CAMPINAS STATE UNIVERSITY FACULTY OF MECHANICAL ENGINEERING

COMMISSION FOR POST-GRADUATE STUDY IN MECHANICAL ENGINEERING

Evaluation of impacts of clean technologies and substitution of cooking fuels in urban residences in

Tanzania

Author: Godfrey Alois Sanga Thesis advisor: Prof. Dr. Gilberto De Martino Jannuzzi

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CAMPINAS STATE UNIVERSITY FACULTY OF MECHANICAL ENGINEERING

COMMISSION FOR POST-GRADUATE STUDY IN MECHANICAL ENGINEERING

PLANNING OF ENERGY SYSTEMS

Evaluation of impacts of clean technologies and substitution of cooking fuels in urban residences in

Tanzania Author: Godfrey Alois Sanga Thesis advisor: Prof. Dr. Gilberto De Martino Jannuzzi Course of studies: Planning of Energy Systems

Academic Master’s degree dissertation presented to the Commission for Post-Graduate Study of the Faculty of Mechanical Engineering, as a requirement for obtaining of the title of Master in Planning of Energy Systems.

Campinas, 2003 São Paulo - Brazil

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Catalogue card prepared by the engineering area library – BAE - UNICAMP

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CAMPINAS STATE UNIVERSITY FACULTY OF MECHANICAL ENGINEERING

COMMISSION FOR POST-GRADUATE STUDY IN MECHANICAL ENGINEERING

PLANNING OF ENERGY SYSTEMS ACADEMIC MASTER’S DEGREE DISSERTATION

Evaluation of impacts of clean technologies and substitution of cooking fuels in urban residences in

Tanzania

Author: Godfrey Alois Sanga Thesis advisor: Prof. Dr. Gilberto De Martino Jannuzzi

Prof. Dr. Gilberto De Martino Jannuzzi, Chair FEM-UNICAMP Prof. Dr. José Tomaz Vieira Pereira FEM-UNICAMP Prof. Dr. Luiz Augusto Horta Nogueira UNIFEI

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Dedication

To my parents, Alois and Maria-Magdalena, for their tireless struggle and dedication, I share all of the happiness which they are

undoubtedly feeling at this time (“in memoriam”)

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Acknowledgements

To the partnership of the interchange project entitled Exchange of sustainable energy

professional, which gave me the opportunity and resources to carry out this work.

To Prof. Dr. Gilberto De Martino Jannuzzi, for guidance in the preparation of the

thesis, a guidance which was sure, attentive, helpful, kind and patient—and critical when

necessary. I value his guidance, which was always given with creativity and the ability to

choose the best path to be followed in the field of scientific improvement and in that of

personal relations.

To Rodolfo Dourado Maia Gomes, Adriano Jerônimo da Silva and Ana Luiza Pompeo

de Tisselli for their help from the first day that I arrived in Brazil and for their suggestions for

improving this work.

To Ema Maria Duarte and Claudiana Ribeiro de Santana for checking the spelling and

grammar of the final work. To my friends Herculano, Rodrigo, Raúl, Cleci, Fabiana, Kamyla,

Fernando and Herivelto, for their help at those difficult times in the preparation of this work.

To the members of the examining board, Prof. Dr. Arnaldo César de Walter and Prof.

Dr. Isaías de Carvalho Macedo, for the criticisms and suggestions which made possible the

improvement of this work.

And to all those who directly or indirectly contributed in any way to the execution of

the study.

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Summary

SANGA, Godfrey Alois, Evaluation of impacts of clean technologies and substitution

of cooking fuels in urban residences in Tanzania; Campinas, Faculty of Mechanical

Engineering, State University of Campinas, 2004. ...p. Dissertation (Master’s degree)

The objective of this work is to quantitatively verify the impacts of improved

efficiency and substitution of cooking fuels in the city of Dar es Salaam in Tanzania, where

approximately 70% of residences use charcoal as the main cooking fuel. The work includes

research on cooking energy and the theories which explain the dynamics in the choice of

cooking fuels, focussing on developing countries. The work also presents the characteristics

defining clean cooking energy, in reference to the recommended standards for the efficiency

of combustion and the emission of air pollutants. One also discusses the mechanisms for

promoting and popularising efficient technologies and clean fuels. And lastly, the work

presents a quantitative analysis on improved efficiency and the substitution of charcoal by

LPG in Dar es Salaam over a twenty-year period. The results are compared within three

scenarios in relation to the demand for cooking fuels, consumption of primary energy sources,

indoor air pollution and the emission of greenhouse gases. The comparison also includes an

analysis of the financial benefits of the use of efficient stoves or of their replacement by LPG.

It is hoped that this work is useful in the formation of policies to improve the supply of

cooking energy in the city, and as well to reduce energy demand, indoor air pollution and the

emission of greenhouse gases coming from the use of charcoal.

Keywords Efficient stoves, fuel substitution, air pollution, greenhouse gases.

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Abstract

SANGA, Godfrey Alois, Evaluation of impacts of clean technologies and cooking fuel

substitution in urban households of Tanzania, Campinas, Faculty of Mechanical

Engineering, State University of Campinas, 2004. ...p. Dissertation for a MSc. Degree.

The objective of this dissertation is to verify quantitatively the impacts of energy

efficiency improvements and cooking fuels substitution in Dar es Salaam, Tanzania, where

approximately 70% of the urban residences use charcoal as the main cooking fuel. The work

includes a study on access to cooking fuels and technologies in developing countries and

establishes characteristics which define them as clean, referring to the established and

recommended combustion efficiency and emissions. Apart from that, various promotion and

popularization mechanisms for the energy efficient technologies and clean cooking fuels are

discussed and analyzed. Finally, the work presents a quantitative analysis on energy

efficiency improvement and its substitution by LPG during the period of 20 years in Dar es

Salaam. The results of the analysis are compared in three scenarios in terms of cooking

energy demand, consumption of the primary energy sources, indoor air pollution and

emission of green house gases. The comparison also includes the financial benefits analysis of

using efficient charcoal stoves or substituting them with LPG. It is expected that this work

will be useful in policy formulation to improve energy supply in Dar es Salaam as well as in

reduction of cooking energy demand, indoor air pollution and emission of green house gases

caused the utilization of charcoal in the city.

Key-words Efficient stoves, fuel substitution, indoor air pollution, green house gases.

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Table of Contents

Dedication ...................................................................................................................... v

Acknowledgements.......................................................................................................vi

Summary .......................................................................................................................vii

Abstract ........................................................................................................................viii

Table of Contents ......................................................................................................... ix

List of Figures............................................................................................................... xi

List of Tables .............................................................................................................. xiii

Nomenclature................................................................................................................xv

Chapter 1 Introduction .................................................................................................. 1

Objective................................................................................................................................. 3

Structure of the work .............................................................................................................. 4

Chapter 2 Literature Review: Cooking Energy....................................................... 6

2.1 Energy consumption and cost .................................................................................... 6 2.1.1 Energy consumption per capita and per quantity of meal prepared. .................. 7 2.1.2 Energy costs per quantity of energy consumed.................................................. 9

2.2 Production and consumption of fuels....................................................................... 11 2.2.1 Bio-mass and the woodfuel gap of the 1970s .................................................. 11 2.2.2 Fossil fuels: mineral coal, kerosene and LPG.................................................. 13 2.2.3 Non-conventional technologies: Biogas, Producer Gas and Dimethyl Ether .. 16

2.3 Tests of efficiency in fuel consumption and production ........................................... 19 2.3.1 Efficiency of stoves.......................................................................................... 19 2.3.2 Efficiency in the production of charcoal .......................................................... 22

2.4 Consumption of traditional fuels and its side effects ............................................... 24 2.4.1 Emission of greenhouse gases.......................................................................... 24 2.4.2 Indoor air pollution........................................................................................... 27 2.4.3 Deforestation and degradation of the Earth...................................................... 35 2.4.4 Definition of clean cooking energy.................................................................. 36

2.5 Energy transition and fuel substitution .................................................................... 38

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2.5.1 Theory and criticism of the “energy ladder” model ......................................... 39 2.5.2 Determinant factors in the choice of fuel ......................................................... 41 2.5.3 Dissemination of efficient bio-mass stoves and kilns ...................................... 42 2.5.4 Programs of subsidies to kerosene and LPG prices. ........................................ 45

2.6 Summary of the Chapter........................................................................................... 52

Chapter 3 Access to and use of cooking energy in Tanzania. ................................ 54

3.1 Socio-economic characteristics................................................................................ 54

3.2 Supply and consumption of the main cooking fuels in Dar es Salaam. ................... 58 3.2.1 Charcoal ........................................................................................................... 59 3.2.2 Kerosene and LPG ........................................................................................... 62 3.2.3 Non-conventional fuels: biogas, mineral coal and natural gas......................... 64

3.3 Comparison of energy costs ..................................................................................... 65

3.4 Cooking energy, air pollution and effects on health ................................................ 68 3.4.1 GG emissions in the consumption of cooking energy...................................... 68 3.4.2 GHG emissions in charcoal production ........................................................... 68 3.4.3 Air pollution and health impacts ...................................................................... 69

3.5 Efficient stove programs in Tanzania....................................................................... 69

3.6 Summary of the chapter............................................................................................ 71

Chapter 4: Quantitative analysis of the impacts of substitution of traditional fuels in Dar es Salaam in Tanzania ............................................................................ 73

4.1 Methodology............................................................................................................. 73

4.2 Tools ......................................................................................................................... 76 4.2.1 Projection of demand ....................................................................................... 76 4.2.2 Greenhouse gases estimates ............................................................................. 79 4.2.3 Concentration of carbon monoxide gas and particulate matter........................ 82

4.3 Description of analysis scenarios ............................................................................ 83 4.3.1. Scenario I: Baseline scenario ........................................................................... 83 4.3.2 Scenario II: Improved efficiency in the production and consumption of charcoal 84 4.3.3 Scenario III: Replacement of charcoal by LPG ............................................... 85

4.4 Results ...................................................................................................................... 86 4.4.1 Demand for cooking energy............................................................................. 87 4.4.2 Consumption of primary energy ...................................................................... 87 4.4.3 Emission of greenhouse gases.......................................................................... 90 4.4.4 Concentrations of carbon monoxide gas and particulates. ............................... 91

4.5 Discussion ................................................................................................................ 92 4.5.1 Savings in the use of efficient stoves and replacement of charcoal ................. 93 4.5.2 Greenhouse gas emissions................................................................................ 95 4.5.3 Concentrations of CO and PM10....................................................................... 95 4.5.4 Imports of LPG and its impacts on Tanzania’s economy ................................ 96

Chapter 5 Conclusions and recommendations. ..................................................... 100

Bibliographic References ......................................................................................... 103

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List of Figures

Figure 1: Population variation and consumption of useful cooking energy in Brazil, between 1973 and 2002. ........................................................................................................................... 8 Figure 2: Percentage of expenditures on energy within family income................................... 11 Figure 3: Trend in average prices for LPG and kerosene in the Persian Gulf between 1993 and 2003.......................................................................................................................................... 16 Figure 4: Modernisation of the use of coal and bio-mass in the production of DME in China18 Figure 5: Variations in overall efficiency by type of stove...................................................... 22 Figure 6: Distribution of the population exposed to air pollution............................................ 28 Figure 7: Variation in concentrations of particulate matter and in ventilation ........................ 30 Figure 8: Variation in the concentration of CO from the burning of firewood........................ 32 Figure 9: Variation in the quantities of emissions for different combinations of fuels and stoves. ....................................................................................................................................... 36 Figure 10: Variations between efficiency and the Environmental Index of the Stove (EIS)... 38 Figure 11: Trend in the consumption of cooking fuels in Brazil between 1973 and 2002 ...... 39 Figure 12: Comparison of stove efficiency and initial costs in the energy ladder model. ....... 40 Figure 13: A Kenyan ceramic stove (KCJ) .............................................................................. 45 Figure 14: Trend in LPG consumption in various market segments in Senegal, 1974 to 1999................................................................................................................................................... 46 Figure 15: Consumption of LPG by social classes in India. .................................................... 48 Figure 16: Variations in the price of production, refinery price and percentage of subsidy on LPG in Brazil between 1998 and 2001. ................................................................................... 49 Figure 17: Trend in annual consumption of LPG [TJ], end price (current) and per capita subsidy, in Brazil between 1973 and 2001............................................................................... 51 Figure 18: Trend in GDP/capita between 1988 and 2002 in Tanzania. ................................... 56 Figure 19: Comparison of the Human Development Index (HDI) and energy consumption per capita of Tanzania and other countries in 2002........................................................................ 57 Figure 20: Trend in consumption of useful energy in the residential sector in Tanzania between 1988 and 1996............................................................................................................ 57 Figure 21: Charcoal marketing chain in Tanzania. .................................................................. 61 Figure 22: Trend in the consumption of kerosene and LPG in Tanzania between 1989 and 2002 [thousand tonnes]. ........................................................................................................... 64 Figure 23: Trend in the price of charcoal in Dar es Salaam, between 1995 and 2000............. 67 Figure 24: Charcoal stoves in Tanzania. .................................................................................. 70 Figure 25: Structure of analysis of the impacts of replacement amongst fuels. ...................... 76 Figure 26: Projection of population between 2002 and 2025. ................................................. 79 Figure 27: Projection of percentages of consumers of different cooking fuels in Scenario I .. 84 Figure 28: Scheme of hypotheses for Scenario II .................................................................... 84 Figure 29: Projection of percentages of consumers of different cooking fuels in Scenario II. 85 Figure 30: Scheme of hypotheses for Scenario III ................................................................... 86

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Figure 31: Projection of percentages of consumers of different cooking fuels in Scenario III86 Figure 32: Projection of demand for cooking energy. ............................................................. 87 Figure 33: Trend in efficiency in charcoal consumption, 2005-2025. ..................................... 88 Figure 34: Projection of demand for charcoal.......................................................................... 88 Figure 35: Trend in efficiency in charcoal production, 2005-2025 ......................................... 89 Figure 36: Projection of wood consumption in the production of charcoal............................. 89 Figure 37: Overall efficiency in the conversion of wood into useful energy........................... 90 Figure 38: Carbon dioxide gas emissions in the consumption of cooking fuels...................... 90 Figure 39: Carbon dioxide gas emissions in the consumption of energy products for cooking and in the production of charcoal. ............................................................................................ 91 Figure 40: Projection of greenhouse gas emissions. ................................................................ 91 Figure 41: Concentrations of CO per capita in [g/m3]. ............................................................ 92 Figure 42: Concentration of TSP per person [µg-PM10/year]. ................................................. 92 Figure 43: Percentage of expenditures for charcoal by quartiles. ............................................ 94 Figure 44: Percentage of expenditures for LPG, with and without taxes ................................ 95 Figure 45: Trend and projection of Tanzania’s exports and imports, 1995-2010.................... 97 Figure 46: Projection of collections and exemptions on the sales of LPG. ............................. 98 Figure 47: Percentage of subsidies needed for various expenditure quartiles. ........................ 99

xiii

List of Tables

Table 1: Estimates of per capita consumption of useful cooking energy, in [GJ/year] ............. 8 Table 2: Comparison of efficiency and consumption of cooking energy in Ungra, India. ........ 9 Table 3: Monthly cooking costs, equivalent to the consumption of 15 kg of LPG in Nigeria in 1987.......................................................................................................................................... 10 Table 4: Percentage penetration of LPG, kerosene and electrical power................................. 15 Table 5: Performance characteristics of charcoal stoves in nine countries.............................. 20 Table 6: Average efficiencies of combinations of stoves and fuel .......................................... 21 Table 7: Comparison of efficiency and economy in the production of charcoal in Thailand.. 23 Table 8: Comparison of kiln yield in charcoal production in Kenya and Brazil ..................... 23 Table 9: Emissions of CO2-equivalents in g-C released, for each 1 MJ of useful cooking energy....................................................................................................................................... 25 Table 10: Global warming potential (GWP) and continuance of the greenhouse gases in the atmosphere ............................................................................................................................... 26 Table 11: Time exposed to pollution for different age groups in Kenya ................................. 27 Table 12: Indoor TSP concentration levels in the developing countries.................................. 29 Table 13: Doses of TSP per quantity of useful energy produced............................................. 29 Table 14: Carbon monoxide gas emission factors by type of fuel used................................... 31 Table 15: Ambient air quality standards in the United States.................................................. 33 Table 16: Determinant factors in the choice of fuel................................................................. 42 Table 17: Price structure of the 13-Kg bottle of LPG and price liberalisation in January 2002 in Rio de Janeiro....................................................................................................................... 50 Table 18: Expenditures of available income per capita, by quartile over a 28-day period in Tanzania. .................................................................................................................................. 56 Table 19: Preferences in the use of cooking fuels in Dar es Salaam in 2001. ......................... 58 Table 20: Percentage of use of different kinds of stoves in Dar es Salaam. ............................ 59 Table 21: Costs of using various cooking fuels in Dar es Salaam, in 1990 ............................. 66 Table 22: Costs of cooking energy per quantity of energy produced, in Dar es Salaam in April 2002.......................................................................................................................................... 67 Table 23: Estimates of GG emissions from the residential and commercial sector in Tanzania in the year 1990 [Gg] ............................................................................................................... 68 Table 24: Greenhouse gas emissions from charcoal production in Tanzania (1990), in Mt.... 68 Table 25: Number of out-patients with diseases caused by acute respiratory infections in Tanzania amongst children under five years of age. ................................................................ 69 Table 26: Number of deaths caused by ARIs in Tanzania amongst children under five. ........ 69 Table 27: Interventions to reduce the disadvantages of use of traditional fuels. ..................... 75 Table 28: Trend in the population of Dar es Salaam between 1967 and 2002 ........................ 78 Table 29: Projection of demand for useful cooking energy..................................................... 79 Table 30: GG emission coefficients and factors ...................................................................... 81 Table 31: Greenhouse gas emission factors for kerosene and LPG [Gg/PJ]. .......................... 81

xiv

Table 32: Costs of use of LPG with prices net of taxes. .......................................................... 94 Table 33: Comparison of greenhouse gas emissions in the production of charcoal in Tanzania, in Mt. ........................................................................................................................................ 95

xv

Nomenclature

Latin letters C The chemical element carbon CH4 Methane gas CO Carbon monoxide CO2 Carbon dioxide H The chemical element hydrogen M Mass [kg] N2O Nitrous oxide NO Nitric oxide NOx Oxides of nitrogen O The chemical element oxygen O2 Oxygen gas Q Energy demand [joules] Greek letters

a, ß Proportions in percentages [%] ? Efficiency S Summation Units GgC Gigagrams of carbon equivalent GJ Gigajoule [109 Joule] h Hectare, equivalent to 10,000 m2; hour J Joule kg Kilogram kgep Kilograms of petroleum equivalent kJ Kilojoule [103 Joule], 1 kcal=4,186 kJ kW Kilowatt kWh Kilowatt-hour [3.6 x 106 Joules] MJ Megajoule [106 Joule] Mt Megatonne (106 tonnes) Mtep 106 tonnes of petroleum equivalent MW Megawatt MWh Megawatt-hour [3.6 x 109 Joules] PJ Petajoule [1015 Joule] t Tonne tpe Tonnes of Petroleum Equivalent TJ Terajoule [1012 Joule] W Watt Acronyms and Abbreviations AFRPREN African Energy Policy and Research Network . ANP National Petroleum Agency of Brazil ARI Acute Respiratory Infection BEN National Energy Balance Sheet

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CAMARTEC Centre of Agriculture Mechanisation and Rural Technologies

CDM Clean Development Mechanism CEEST Centre for Energy, Environment, Science and

Technology . .

CENBIO Biomass Reference Centre NMOC Non-methane Organic Compounds DME Dimethyl Ether FAO Food and Agriculture Organisation FEI Fuel emission indicator GG Greenhouse gas GEF Global Environmental Facility LPG Liquid Petroleum Gas IBGE Brazilian Institute of Geography and Statistics. HDI Human Development Index IPCC Intergovernmental Panel on Climate Change

Scientific Assessment

ITDG Intermediate Technology Development Group JI Joint Implementation (in the Kyoto Protocol) KCJ Kenya Ceramic Jiko [stove] KENGO Kenya Energy and Environment Organisations . MAI Mean Annual Increment [m3/ha/year] MDG Millenium Development Goals NAAQS (United States) National Ambient Air Quality

Standards

OECD Organisation for Economic Co-operation and Development

OTA Office of Technological Assessment (United States).

GWP Global Warming Potential LHV Lower Heating Value [kJ/kg] HHV Higher Heating Value [MJ/kg, MJ/t] GDP Gross Domestic Product GNP Gross National Product GNI Gross National Income SEI Stockholm Environmental Institute TaTEDO Tanzania Traditional Energy Development and

Environment Organisation .

CCT Controlled Cooking Tests KPT Kitchen Performance Tests WBTs Water Boiling Tests TSH Tanzanian Shilling 1 TSP Total Suspended Particles UNDP United Nations Development Program UNEP United Nations Environmental Program UNICEF United Nations Children Fund . URT United Republic of Tanzania USD Dollar, United States currency EPA (United States) Environmental Protection Agency WEA World Energy Assessment WEC World Energy Council WHO World Health Organisation WLGPA World LP Gas Association

.

1 1 USD = 1007 TSH (Bank of Tanzania, September 2004)

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Chapter 1

Introduction

In the majority of the rural areas and in the small cities, the availability of clean fuels2

(kerosene, LPG and natural gas) is intermittent or non-existent, due to the lack of distribution

and marketing infrastructure. That being the case, these fuels are relatively more expensive

than the traditional ones (firewood and charcoal) available in these areas. In countries which

do not produce petroleum or natural gas, they are imported and their prices vary constantly, in

line with the price of petroleum on the international market. The precarious socio-economic

situation and the low buying power of the population3 impede penetration by these fuels into

these areas. In these cases, the population has no other option but to continue using traditional

fuels in inefficient stoves, which are available in abundance at low or even zero cost.

One of the disadvantages of the use of the traditional stoves and fuels, is the low

combustion efficiency. The efficiency of a wood stove is frequently less than 10% (Kammen,

1995; WEC, 1999; Goldemberg and Villaneuva, 2003) and the incomplete burning of the

traditional fuels generates, in addition to carbon dioxide gas (CO2), the products carbon

monoxide (CO), oxides of nitrogen (NOx), nitrous oxide (N2O), methane (CH4), non-methane

organic compounds (NMOC) and total suspended particles (TSP).

The indoor concentrations of air pollutants, even with the use of efficient stoves4, are

higher than the levels recommended by the World Health Organisation (WHO), and the

2 Also known as commercial or modern fuels, these refer to a source of energy which is of high quality and

efficiency of combustion. Normally they are marketed in open markets, and include, for example, electrical power and petroleum derivatives, and exclude the traditional sources such as firewood and dung.

3 The total number of persons who are residents of a country, whether or not they are citizens 4 An efficient stove is a stove which has a greater capacity for transferring the energy generated by the burning of

fuel, to the pot; it thus has as it principal characteristic, greater economy in its consumption. Today, in addition to high thermal efficiency, an efficient stove ought to produce less pollutant gases and particulates during its use.

2

United States Environment Protection Agency (EPA). For example, a traditional stove5 and

an efficient stove produce TSP in concentrations which are seven and three times greater

respectively than the level recommended by the WHO and EPA, which is 120 mg/m3 (Section

2.4.3). High concentrations of TSP indoors increase the risk of acute respiratory infections

(ARI)6 and other diseases such as cancer and tuberculosis. These infections are among the

four greatest causes of death and disease in the developing countries (Bruce, 2002).

The effects of the emission of air pollutants extend globally, since the burning of the

traditional fuels produces greenhouse gases7 (GG). The contribution to the inventory of

greenhouse gases by the burning of traditional fuels is potentially greater, since more than

half of the world’s population uses this kind of fuel (UNDP, 2002). The greenhouse gases

CO2 and CH4 are the main ones which most cause global warming. The burning of bio-mass

contributes to the inventory of GGs, when harvested in a non-sustainable way. In the cases in

which the rate of replanting and reforestation is greater than the rate of harvesting, CO2

absorption occurs, in this way annulling the net effect of the CO2 in the atmosphere. A higher

rate of consumption of bio-mass (firewood and charcoal8) relative to its replanting, is one of

the biggest causes of deforestation. In some locations, the lack of its supply obliges

consumers to use agricultural residues and dung instead of firewood.

The use of efficient stoves, replacement of traditional fuels and improvement in

ventilation, are the solutions found for reducing indoor and outdoor air pollution. These

measures follow that which is known as the energy ladder model, which explains the theory

of dynamics of choice, adaptation and use of various combinations of stoves and fuels

(Section 2.51). The energy ladder theory suggests that with increased affluence, consumers

progressively exchange traditional fuels (dung, agricultural residues, firewood, charcoal) for

the modern ones (kerosene and LPG), as if going up a ladder. There is increased efficiency

and reduced pollution as one rises up the energy ladder. However, it has been proven that fuel

5 This refers to an inefficient stove which uses traditional fuels such as firewood, agricultural residues and dung 6 Respiratory tract infections caused by inhalation of air containing harmful gases 7 Greenhouse gases accumulate in the atmosphere and act as a blanket preventing the escape of the infrared energy

reflected from the earth’s surface, and in that way, the temperature of the earth increases 8 Charcoal is a product derived from wood, characterised as a solid, porous material which is easily combustible

and capable of generating large quantities of heat (30.8 MJ/kg). It may be produced artificially by pyrolysis of wood, or originate from a long natural process called carbonisation. In carbonisation, organic substances, principally vegetable, are submitted to the action of the earth’s temperature during around 300 million years and get transformed into mineral coal. As a function of the nature of the two processes, charcoal is also called artificial, and mineral coal natural (Barsa (1998), in Barcellos (2002)).

3

choice is not one-dimensional; consumers normally use more than one kind of fuel and stove,

depending on their accessibility, availability and convenience (Masera et al, 2000). In that

way, energy consumption for cooking is made up of multiple fuels, which do not follow a

progressively linear transition as suggested in the energy ladder theory.

Dar es Salaam, the largest city in Tanzania, is one of the cities in sub-Saharan Africa

which are highly dependent on charcoal as a cooking fuel, both in the residential as well as

the commercial sector. The current population of Dar es Salaam is approximately 2.5 million

inhabitants, and the rate of urbanisation is between 4 and 6% per year. This population

number is expected to double within twenty years. Around 70% of the population of the city

uses charcoal as their first choice amongst the sources of energy for cooking (Section 3.2.1).

The energy transition is slow toward the modern fuels, and there are no expectations in the

short term of an increase in the use of clean fuel technologies.

Objective

This work seeks to quantitatively analyse, over a twenty-year period, the impacts of

improved efficiency in the consumption and production of charcoal, and of the introduction of

LPG on a large scale in the consumption of cooking fuels in urban households in Tanzania.

This objective is based on the assumption that improved efficiency or the use of gas or liquid

fuels, reduces energy demand and the consumption of primary energy resources, as well as

indoor air pollution and the emission of greenhouse gases.

This work fits within the overall objective of the United Nations (UN), oriented to

achieving sustainable development in its Millenium Development Goals (MDGs). UN (2004)

finds that improvements in the supply of cooking energy are needed in order to reach more

respectable living conditions for the population. The MDGs aim to reduce the number of

persons without electrical power and of those who do not have access to clean cooking fuels.

LPG is mentioned as the cooking fuel which is in line with these goals, and its minimum

consumption is defined as around 1 GJ/year. The sixth MDG mentions an increase in access

to modern fuels as one of the interventions in order to ensure a sustainable environment.

According to the UN, clean fuels will reduce the residential demand for bio-mass, in this way

reducing the clearance of trees and the degradation of the earth, and as well reducing

greenhouse gas emissions and indoor air pollution. The MDG guidelines require that each

4

country institute sustainable development policies aimed at reducing the degradation of

natural resources.

The result of this work may also be important in the international negotiations on the

reduction of greenhouse gas emissions, given that Russia has ratified the Kyoto Protocol on

climate change9 and it will enter into effect on February 16, 2005. The Kyoto Protocol, signed

in December 1997, created mechanisms to combat the emission of greenhouse gases: carbon

market, Joint Implementation (JI) and Clean Development Mechanism (CDM). The Protocol

stipulated, as a overall rate, that the industrialised countries reduce their emissions of such

gases by 5% (between 2008 and 2012), in relation to the volume emitted in 1990. In carbon-

emitting businesses, the industrialised countries—the greatest polluters—may invest in

reducing greenhouse gases in other countries and thus gain carbon credits. In addition to

reducing greenhouse gas emissions (discussed in Section 2.4), the JI and CDM projects may

also diminish local pollution and reduce its impacts on health, improve energy supply

security, create jobs and make possible technology transfer. These secondary benefits may

push the government of Tanzania to negotiate climate change projects, in the area of use of

bio-mass for cooking, together with other outside investors or through the CDM.

Structure of the work

This work is organised into five chapters. Chapter 1 is the introduction, while Chapter 2

provides a literature review on clean cooking energy in the residential sector, with the

objective of analysing cooking fuels and technologies, indoor and outdoor air pollution,

definition of clean cooking fuel and the determinant factors in choice of fuel. Chapter 2 also

presents the international experience in accelerating the penetration of the clean cooking

technologies and fuels. The initiatives are also discussed, of accelerating the penetration of

efficient stoves and modern fuels for food cooking in the rural and semi-urban areas.

Chapter 3 presents the current situation as regards supply of cooking energy in the

urban areas of Tanzania, and contains information on socio-economic characteristics, demand

for and consumption of cooking energy, emission of air pollutants and initiatives for

improvement in the supply and consumption of cooking energy.

9 Further information at the following site: http://unfccc.int/kyoto_mechanisms/items/1673.php

5

Chapter 4 uses the information developed in Chapters 2 and 3 in order to identify the

possibilities for meeting the demand for cooking energy in Dar es Salaam and to

quantitatively analyse the impacts of efficiency improvement and fuel substitution. The

possibilities are grouped into three scenarios, which are analysed in terms of demand for

cooking energy, consumption of primary energy, indoor air pollution, emission of greenhouse

gases and costs per unit of energy produced. Chapter 5 is the conclusion of the work.

6

Chapter 2

Literature Review: Cooking Energy

The use of traditional fuels coming from bio-mass, in inefficient stoves, is common in

the rural areas and in the poor outlying urban areas of the developing countries. More than

half of the world’s population continues to use solid cooking fuels (UNDP, 2002). The

inefficient use of bio-fuels increases the consumption of bio-mass and is associated with both

indoor and general air pollution. Due to the lack of marketing infrastructure for the modern

fuels, which are considered cleaner, replacement of the traditional fuels has been slow and

inconsistent. This chapter discusses alternative cooking fuels and technologies, indoor and

general air pollution and the determinant factors for fuel replacement.

2.1 Energy consumption and cost

Amongst poor families, energy for food cooking and heating makes up 90% to 100% of

residential energy consumption10 (WEC, 1999). According to the WEC, the most common

cooking fuels are grouped into three categories: modern (electrical power, LPG), intermediate

(kerosene, charcoal) and traditional (firewood, dung, agricultural residues). Approximately

three billion people, the majority in developing countries, prepare their meals using solid fuels

coming from bio-mass or coal (UNDP & World Bank, 2002).

It is calculated that more than 2.5 billion people use bio-mass, including firewood,

charcoal, agricultural residues and dung, as the primary source of cooking energy (Reddy,

1997). In several underdeveloped countries, the use of bio-mass accounts for as much as 95%

of home energy consumption (Arungu-Olede, 1984, in Saldiva and Miragila, 2004). Despite

the decrease in the consumption of bio-mass in the world, it has been proven that its use has

10 This is the energy needed for cooking food, heating, lighting, refrigeration and communication via radio,

telephone or television.

7

increased amongst the poorest (Bruce et al., 2002). The contribution of bio-mass to the

consumption of primary energy varies between 80% to 90% (poor countries), to 55% to 65%

(middle-income countries) and 30% to 40% (high-income countries). Charcoal is extensively

used in the majority of the urban areas in Africa, while coal is common in countries such as

China, South Africa and Mozambique (UNDP, 2000). Other cooking fuels include those

derived from petroleum, like kerosene and LPG.

2.1.1 Energy consumption per capita and per quantity of meal prepared. Per capita consumption of traditional fuels in the rural areas varies significantly,

depending on the efficiency of the stoves and the kind of fuel used. Consumption of firewood

or agricultural residues in meal preparation varies between 11.5 and 49 MJ/day per capita

(WEC, 1999). In Bangladesh, for example, between 1976 and 1982 cooking energy

consumption per capita varied between 1.6 and 8.1 GJ/year, resulting in an average of 4.7

GJ/year (Ali, 2002). Geller and Dutt (1993), citing Astra (1981), show that at the beginning of

the eighties, per capita final energy consumption11 for cooking in South India was around 8.0

GJ/year, a value comparable to that estimated by Ali (2002).

In residences where there is employment of modern fuels, high-efficiency stoves and

preparation of light meals, per capita consumption of useful cooking energy12 varies around

2-3 MJ/day (WEC, 1999). In the 1970s in the United States, average per capita consumption

of cooking energy varied around 1.5 to 2.0 GJ/year, using a gas stove (Openshaw, 1978, in

Geller and Dutt, 1983).

In Brazil, consumption of useful energy per capita declined from 1.13 GJ/year in 1973

to 0.90 GJ/year in 2002, with average consumption being around 0.98 GJ. During this period,

consumption of useful cooking energy13 increased at approximately the same rate as

population growth, and one observes that there is no direct relationship between growth in

consumption and growth in the Gross Domestic Product (GDP)14 of the country (BEN, 2003)

11 The energy contained in the form which is ready for use, for example charcoal, firewood, kerosene, LPG and

electrical power. 12 The proportion of final energy which gets to the pot and is in fact used for the cooking, depending on the

efficiency of the stove. 13 Only the main fuels were considered: firewood, LPG, piped gas and charcoal. 14 Gross Domestic Product refers to the total of goods and services produced and marketed within the domestic

territory of a given country.

8

as presented in Figure 1. Consumption of useful cooking energy increases with the increase in

population.

Figure 1: Population variation and consumption of useful cooking energy in Brazil, between 1973 and 2002.

0

50

100

150

200

1973 1978 1983 1988 1993 1998

, ]P

opul

atio

n [m

illio

ns]C

onsu

mpt

ion

[GJ

0

250

500

750

1000

GD

P [b

illio

n U

SD] population

Consumptionof usefulenergyGDP [currentdollar]

Source: BEN (2003), IPEA (2004).

Large families enjoy an economy of scale in the consumption of fuels, and in general

that consumption declines the greater the family size (Chaudhuri and Pfaff, 2003). The

consumption of useful cooking energy per capita is also discussed in the works of Revelle

(1976), Bravo (1979), Goldemberg (1983) and Goldemberg et al. (1987), as cited by Pachauri

and Spreng (2003). From the three paragraphs above, per capita consumption of useful

cooking energy may be estimated at a constant value of around 1 GJ/year, as presented in

Table 1.

Table 1: Estimates of per capita consumption of useful cooking energy, in [GJ/year]

Author/Source Kind of Fuel Per Capita Consumption

Average Consumption15

[GJ/year] WEC (1999) Firewood, agric. residues. 11.5 – 45 MJ/day 1.546 Ali (2002) Firewood, agric. residues. 1.6 - 8.1 GJ/year 0.727 Geller and Dutt (1993) Firewood, agric. residues. 8.0 GJ/year 1.200 WEC (1999) LPG (useful energy) 2.0 - 3.0 MJ/day 0.913 Geller and Dutt (1993) LPG/Natural gas 1.5 - 2.0 GJ/year 0.875 BEN (2003) LPG/firewood 0.9 - 1.13 GJ/year 1.015

Average

(GJ/year/capita) 1.046

Energy consumption also depends on the kind of foodstuffs and the number of meals

prepared per day (WEC, 1999). The preparation of the main foodstuffs (rice, maize, beans)

uses more energy than the preparation of the subsidiary ones (vegetables and meats). Using a

wood stove for a medium-sized family of five people, preparation of the majority of the

15 Efficiency in the consumption of bio-mass and LPG was considered as around 15% and 50% respectively.

9

foodstuffs consumes between 12 and 38 MJ/kg, while the cooking of the beans consumes up

to 225 MJ/kg, according to WEC (1999).

The consumption of energy in meal preparation depends, therefore, on the efficiency of

the combination between stove and fuel. Dutt and Ravindranath (1993) show that the use of

an electric stove in Ungra, in India, expends less energy than other kinds of stoves in the

preparation of a typical meal (rice, cowpeas, millet and greens). The traditional wood stove

consumes 3.76 and 4.74 times more energy than the kerosene stove and the LPG stove

respectively, as presented in Table 2. The combination of stove and fuel with greatest

efficiency, consumes the least energy. One observes as well that the three-burner wood stoves

have greater power and the preparation of the meal takes less time when using these stoves.

Table 2: Comparison of efficiency and consumption of cooking energy in Ungra, India.

Specific consumption of the fuel Fuel Stove Efficiency

[%] Physical unit

[MJ/kg of meal]

Average cooking

time [minutes]

Firewood 3-stone wood fire 15.6 217 g 3.44 101 Traditional, 3-burner 14.2 271 g 4.31 62 ASTRA ole, 3-burner 33.5 141 g 2.24 62 Swosthee MS-4 17.2 183 g 2.91 111 Charcoal Traditional (metal) 23.2 95 g 2.38 n/a Dung (in pieces) Traditional, 3-burner 11.1 304 g 4.00 n/a Sawdust Improved IISc16 30.4 253 g 4.02 n/a Biogas KVIC burner 45.1 0.05 m3 1.23 103 Kerosene Nutan 60.2 26.1 g 1.13 106 Perfect 40.4 26.6 g 1.15 131 LPG Superflame 60.4 20.1 g 0.91 76 Electrical power Hot plate 71.3 0.17 kWh 0.64 99

Source: Dutt and Ravandranath (1993)

2.1.2 Energy costs per quantity of energy consumed The unit cost of cooking energy varies significantly between the various combinations

of stoves and fuels. In the cases in which the cost of the bio-mass is zero, it becomes the

cheapest cooking fuel. In Table 3, Leach and Gowen (1987), in Baranzini and Goldemberg

(1996), presented costs for the use of various fuels, equivalent to the use of 15 kg of LPG in

Nigeria in 1987. One observes that the use of firewood represents the most expensive

alternative for cooking. Considering the proportion represented by energy expenses to be

around 5%, monthly family expenditures should be around 192 USD if firewood is used; 68

16 Indian Institute of Science (IISc)

10

USD if it is charcoal; 14 USD for kerosene; 25 USD with LPG; and 45 USD if it is electrical

power.

Table 3: Monthly cooking costs, equivalent to the consumption of 15 kg of LPG in Nigeria in 1987 Fuel Cost of fuel

[k/unit] Calorific

value [MJ/unit]

Efficiency of stove

[%]

Actual cost of

the energy [k/MJ]

Average expenditures [USD/month]

Firewood (dry) 17/kg 14.7/kg 8-13 8.9-14.5 9.4 Charcoal 22/kg 25.1/kg 20-25 4.4-5.8 3.4 Kerosene (wick, one burner) 10/litre 34.8/litre 30-40 0.7-1.0 0.7

LPG 34/kg 49.0/kg 45-55 1.3-1.5 1.3 Electrical power 6/kWh 3.6/kWh 60-70 2.4-2.7 2.2

Note: Original prices expressed in kobo (one cent of a Naira, the Nigerian currency, equivalent to 0.25 USD in 1987) Source: Leach and Gowen (1987) in Baranzini and Goldemberg (1996)

In home energy consumption, poor families spend less financial resources on energy

than the rich families, since they consume less commercial fuels. Meanwhile, they spend the

greater part of their time in the collection, production and use of energy. According to Reddy

(1997), in Pakistan 5.4% of the poorest families’ expenditures is dedicated to energy, while

the rich families spend 22.2%. As income level rises, the proportion of consumption on

cooking declines, while the proportion of consumption for heating of water and the use of

electrical appliances increases. In addition, rich families use the most efficient stoves, thus

significantly reducing their consumption of cooking energy. Efficient stoves are more

expensive than the traditional ones, and therefore their use is most common only amongst the

families with a high income level.

In the urban areas, unlike the situation in the rural areas, consumers pay for the energy

which they consume. Barnes (1995) shows that in 20 thousand urban homes in 45 cities in 12

countries, poor families spend from 15% to 22% of the monthly income on energy. According

to the author, around 20% of homes correspond to the poorest, presenting a monthly income

of 7 to 11 USD per capita, as presented in Figure 2. The ideal percentage of expenditures on

energy is between 5% and 10%, as occurs with consumers of the modern fuels (Barnes,

1995).

11

Figure 2: Percentage of expenditures on energy within family income

0

5

10

15

20

25

7 11 14 19 24 31 41 62 107 216Monthly per capita income [USD]

Ene

rgy

expe

nses

: P

erce

ntag

e of

in

com

e[%

]ElectricalpowerLPG

Kerosene

Charcoal

Firewood

Source: Barnes et al. (1994).

2.2 Production and consumption of fuels

2.2.1 Bio-mass and the woodfuel gap of the 1970s The woodfuel gap arose in a period in which there was a concern that the rate of

consumption of woodfuel was greater than that of reforestation (WEC, 1999). The Food and

Agriculture Organisation (FAO) revealed in 1980 that more than one billion people were in a

situation of woodfuel shortfall. In the countries of the Sahel17, the rate of firewood

consumption was greater than that of reforestation, by 70% in the Sudan, 75% in the north of

Nigeria, 150% in Ethiopia and 20% in Niger. In 1988 the World Bank recommended that the

rate of reforestation in sub-Saharan Africa18 would have to increase in 2000 by fifteen times

in order that the rate of consumption be equal to the reforestation rate.

However, contrary to this hypothesis, it was shown that only a small part of the bio-

mass used in rural homes had its origin in the forest reserves and commercial plantations. The

main sources of bio-mass are areas around homes, along roads and in the tracts of cultivated

land, amongst others (Dutt and Ravindranath, 1993). In India, for example, around 80% of all

of the bio-mass consumed does not involve cutting down of trees, but rather involves the

collection of bio-mass like twigs, branches, roots and agricultural residues, according to Dutt

and Ravindranath (1993). Since the importance of these sources was neglected, the estimates

17 The Sahel is a semi-arid region to the south of the Sahara Desert, making up a transitional zone between the

desert and the tropics, running in an East-West direction and including countries like Senegal, Chad, Mali, Burkina Fasso, Niger, Nigeria, Sudan, Ethiopia, Eritrea, Djibouti and Somalia.

18 Sub-Saharan Africa includes all of the countries of the African continent except the Republic of South Africa (in this document referred to simply as South Africa), and the countries of north Africa: Algeria, Egypt, Libya, Morocco and Tunisia.

12

were highly exaggerated. The Food and Agriculture Organisation (FAO) highlights that

clearing for agricultural activities is the largest cause of deforestation, being responsible for

70% of the deforestation in Africa between 1950 and 1983 (FAO, 1995b). According to the

organisation, the consumption of woodfuel corresponds to only 7% of deforestation.

The greatest concern, however, is the growing consumption of bio-mass in the urban

areas, principally in the production of charcoal. FAO (1995b) reports that 26 million tonnes of

charcoal were produced in the world in 1995, and the rate of production was increasing by

approximately 3% per year during the period from 1991 to 1995. Charcoal represents around

12% of energy consumption from fuels which come from bio-mass. Pennise et al. (2004) cite

the estimate made in Rosillo-Calle et al. (1996), in which they point to the production of 100

million tonnes of charcoal in 1995. The authors explain that this large variation between the

data from the FAO (1997) and from Rosillo-Calle et al. (1996) is due to the fact that a large

part of the charcoal is produced and marketed informally, which makes more precise

estimates difficult.

Brazil is the largest producer of charcoal in the world, producing in 1999 7.1 million

tonnes or 25% of world production (Pinheiro and Sampaio, 2001, in Barcellos, 2002). In

2002, the country produced 7,353 thousand tonnes (BEN, 2003), with the industrial sector

being the largest consumer of charcoal, responsible for 89%, followed by the residential

sector (9.5%) and the commercial sector (1.5%). Seventy-five percent of all of the charcoal

produced in Brazil derives from reforestation timber, with 52% of the forests planted being

composed of eucalyptus. The production of charcoal is what consumes the most reforestation

timber, almost 30% of total Brazilian industrial timber consumption. Only 25% of the

production of charcoal comes from first-growth forests (Barcellos, 2002).

Due to its great fragility, charcoal generates fine particles arising from its breakage

during production, transport and handling. Charcoal fines are not used in residential

consumption, since they burn slowly and produce a great deal of smoke, due to the high

quantity of sand and clay in its composition19. Antunes (1982), cited by Cortez (1997),

calculates that approximately 20% of the total volume of the charcoal produced gets

transformed into fines.

19 Sand and clay are entrained from the soil during charcoal production.

13

2.2.2 Fossil fuels: mineral coal, kerosene and LPG (Mineral) coal

Coal provides 25% of total energy demand in the world, mainly for generation of

electrical power and heat (World Bank, 2004). Between 1980 and 1995 the demand for coal

increased to one billion tonnes, mainly for the generation of electrical power and production

of steam. China is the largest consumer of coal, in 1996 consuming 1,500 million tonnes,

while India as a country is the third largest producer of the fuel. Mineral coal is also used for

cooking in the residential sector in China, South Africa, India and Mozambique (Ellegard,

1993; Edward et al. (2003)). Van Horen and Eberhard (1999) highlight that the consumption

of coal in the residential sector of South Africa varies between 1.5 and 7.4 million tonnes per

year, and they suggest that consumption ought to reach three million tonnes/year. Van Horen

et al. (1993) evaluate that one million homes (five to six million people) were using

bituminous coal for cooking in South Africa.

Coal contains sulphur and a large portion of ash, it thus being one of the most

dangerous fuels for human health. In South Africa, for example, the sulphur content in coal is

around 1%, relatively low in relation to international standards, but nevertheless the ash

content is around 40%. Thus the burning of coal in domestic stoves emits a high quantity of

particulates (van Horen et al., 1996). Accordingly, the production of coal for domestic use

requires a great deal of cleaning in order to remove all of the impurities and improve its

combustion characteristics, and consequently diminish the emission of air pollutants.

Coal is also the worst in terms of chemical reactivity, due to difficulties in lighting and

burning it; for example, when the quantity of coal in the stove declines, the liveliness of the

combustion also declines (Foley and Buren, 1980). With a density three to four times greater

than charcoal, a given volume of coal can produce three to four times more heat than the same

volume of charcoal. This is the cause of cases of overheating and unexpected burns when

used for cooking, since it is very probable that out of forgetfulness, the user uses it in the

same quantity in which they use charcoal. The lower heating value of charcoal varies between

20.1 GJ/t and 29.30 GJ/t (TaTEDO, 2001; Baranzini and Goldemberg, 1996 and BEN, 2003).

14

Kerosene

Kerosene is a liquid fuel derived from the refining of petroleum and used for cooking in

pressurised stoves20 or in the normal ones with wick burners. With a lower heating value of

around 44.75 GJ/tonne (BEN, 2003) its greatest use, however, is in lighting, mainly in the

countries with poor access to electricity. This leads to its penetration in the rural areas being

greater than that of LPG. Kerosene vaporises rapidly and burns more neatly than the solid

fuels. Meanwhile, its greatest disadvantages include the high fire risk, poisoning of foodstuffs

and the low power of kerosene burning devices, in comparison with the burning of LPG,

charcoal or firewood. Eberhard (1999) shows that a kerosene stove has a power rating of

around 2 kW, while that of a wood stove is 6 kW. Accordingly, its use is primarily for

cooking of light foods and boiling water.

Liquid petroleum gas, LPG.

LPG is a gaseous fuel, a petroleum derivative with a lower heating value of 47.4 GJ/t,

according to BEN (2003). Consumption of LPG has been growing in recent years, mainly

amongst high-income families in the urban areas. For example, in Africa consumption of LPG

grew from 1,898 thousand tonnes in 1980, to 5,424 thousand tonnes in 1995, giving an

increase in residential consumption of 5.2% to 14% (FAO, 1995). World LPG demand in

2000 was around 200 million tonnes, with an expectation of it increasing to 237 million

tonnes in 2005, according to the World Liquid Petroleum Gas Association (WLPGA, 2004).

Average growth in the consumption of LPG is around 5% per year.

According to WLPGA (2004), Asia is the largest consumer of LPG in the world. In

2003 the continent used 60 million tonnes, with 65% of consumption directed to the

residential and commercial sectors. Over the last five years, demand for LPG in China has

increased from eight to sixteen million tonnes, while in India demand grew from five to eight

million tonnes. In Central and South America, LPG consumption is at 27 million tonnes,

while in Africa demand was around eight million tonnes. The use of LPG is common in a

large part of Latin America, mainly in Brazil, where nearly all homes have access to the gas,

even in the remote areas (WLPGA, 2004). The association highlights that in Latin America

20 The pressurised stove has a pump to increase the velocity of the kerosene upon leaving the orifice of the burner.

The kerosene under pressure leaves the orifice of the nozzle (burner), creating an area of low pressure around the nozzle, suctioning the air to the kerosene jet. This creates a kerosene mixture rich in air, facilitating its burning. That being the case, pressurised kerosene stoves have greater thermal efficiency and power than the other non-pressurised ones.

15

the use of piped natural gas in the urban areas was one of the factors which reduced the

growth rate in demand for LPG on this continent.

In Africa and in the poor countries of Asia, the lack of distribution infrastructure and

the high costs for LPG and gas stoves, impede its greater penetration in the rural areas. Floor

and Groove (1990), in Beranzini and Goldemberg (1996), show that the majority of the poor

families do not save enough, thus making impossible the spending of a lot of money, for

example in the purchase of gas stoves. Table 4 presents rates of penetration of LPG in various

developing countries.

Table 4: Percentage penetration of LPG, kerosene and electrical power Country LPG Kerosene Electrical

power All non-solid fuels

Brazil 92.3 0.1 1.6 92.8 Nicaragua 29.0 1.8 1.0 31.7 South Africa 7.9 43.2 45.8 85.8 Vietnam 22.3 8.0 13.1 33.0 Guatemala 44.9 5.5 2.0 50.1 Ghana 5.4 1.1 0.4 6.9 Nepal 1.6 7.1 0.3 9.0 India 16.0 7.9 0.2 24.3

Source: World Bank (a) (2003).

In the unregulated market, the prices for kerosene and LPG have varied significantly in

recent years, in accordance with the international prices of these fuels. The prices for kerosene

at the petroleum refineries21 in the Persian Gulf, varied between 12 USD/barrel and 36

USD/barrel, between January 1993 and January 2003 (Petroleum Economics Limited, 2004).

Over the same period, LPG prices varied between 150 USD/t and 370 USD/t in 2003, as

presented in Figure 3. LPG and kerosene prices also vary significantly over the year; for

example, between June 1996 and January 1997, prices rose from 150 USD/t and 22

USD/barrel, to 340 USD/t and 33 USD/barrel, for LPG and kerosene respectively.

21 An industrial facility where crude oil gets processed into other derivative products such as kerosene and LPG.

16

Figure 3: Trend in average prices for LPG and kerosene in the Persian Gulf between 1993 and 2003

0

100

200

300

400

jan.93 jan.95 jan.97 jan.99 jan.01 jan.03

LP

G [U

SD/t

]

0

10

20

30

40

Ker

osen

e [U

SD/b

arre

l]

LPG

Kerosene

Source: Petroleum Economics Limited (2004).

Due to the great fluctuation in LPG and kerosene prices on the international market, in

some countries subsidy programs have been introduced to keep prices to the consumers

stable. However, deregulation of the oil sector progressively exposed consumers to price

volatility, according to the 2002 UNDP energy report, World Energy Assessment, WEA.

2.2.3 Non-conventional technologies: Biogas, Producer Gas and Dimethyl Ether Biogas

Biogas is produced by the anaerobic decomposition of organic matter. Biogas is

inflammable, made up mainly of methane gas (CH4) in proportions of 40 to 70% of total

volume22. The composition of the biogas depends on the raw material which originates it, and

the gas’ temperature and pressure. According to Coelho et al. (2000), the lower heating value

of raw biogas is around 21.6 MJ/m3, which compares to the energy content of one litre of

diesel oil, but is less than the heating value of purified biogas, which is 34.2 MJ/m3. The

volume of 1 m3 of gas can provide energy for the preparation of three meals for a family of

five to six persons (Kristoferson 1991, in ITDG 2003).

In communities where there is availability of inputs like manure and water, the use of

biodigestors has greater potential for domestic use. China and India are the countries known

for having the largest programs for dissemination of this technology. Over the period from

1973 to 1978, the biogas program in China had built seven million biodigestors for domestic

use, and in 1994, five million biodigestors were operating satisfactorily (UNDP, 2002). The

dissemination of biodigestors did not meet with success in Africa, due to the high costs for

22 Other constituents and their proportions by volume, include carbon dioxide (30-60%), hydrogen (0-1%),

hydrogen sulphide (0-3%) and other gases (1-5%) (Coelho et al., 2000).

17

installation and maintenance, and the lack of technical support for users. According to the

UNDP (2002), the experience in dissemination of biodigestors for cooking shows that in the

short term, the expectation is very low for expansion of its domestic use.

Producer gas

Producer gas is produced by the gasification of bio-mass or other hydrocarbons like

(mineral) coal. The gas, basically composed of the gases carbon monoxide, hydrogen and

nitrogen, has been used for heating and cooking within the industrial and residential sectors

(FAO, 1986). During the Second World War, this gas was the principal fuel driving stationary

and automobile motors. Following the war, there was an increase in the supply of fossil fuels,

which were cheaper, and interest in the use of the gas declined. The lower heating value of

producer gas is 5.2 MJ/Nm3, less than that of natural gas (34.6 MJ/Nm3) and of LPG (86.4

MJ/Nm3) (FAO, 1986). Despite the low heating value of producer gas, the quantity of

emissions from its use is relatively less than that of LPG or kerosene. Producer gas is also

known as an alternative gas to biogas, and has been used as a fuel for the cooking of

foodstuffs in many European and Asian countries since the seventeenth century (UNDP,

2002).

Recently, interest has grown in the producer gas produced from coal and bio-mass, as

an intervention to reduce air pollution from the burning of unprocessed bio-mass and mineral

coal. In China, domestic use of producer gas for food cooking has now been relatively

developed since 1996, when research programs began which drove the development of this

technology. In the Shangdong region, twenty gasifiers already exist which produce gas and

supply homes through a system of piped gas. In 1996, there were 216 homes in Tengzhai in

the Shangdong region which were benefiting from this technology (UNDP, 2002). It is

estimated that in China, with the use for energy purposes of 60% of the available agricultural

residues, it will be possible to generate energy to meet the demand for cooking in all rural

areas of the country (UNDP, 2002). However, research efforts are being carried out aimed at

reducing environmental impacts from the tar produced during production of the gas. The tar

produced with producer gas may contaminate and pollute the water on the surface and in the

soil. These research efforts also aim to avoid accidents which may take place due to CO

leakage during burning of the gas, given that 20% of the gas is composed of CO.

18

Dimethyl Ether Gas (DME)

Dimethyl ether gas (DME) has characteristics similar to those of LPG and is used as a

cooking gas, in addition to other energy and industrial uses. It is produced on the basis of

various carbonaceous substances, such as natural gas, mineral coal and bio-mass. The

transport and distribution of DME may use the same distribution infrastructure as LPG, in

addition to the advantages mentioned previously. The technological development and

production of the gas on a large scale are in the initial phases. World production of the gas is

around 150,000 t/year and it is foreseen that the technology will be ready in commercial terms

to enter the market between 2010 and 2015 (Larson and Tingjin (2003) and UNDP (2002)).

In China there are significant initiatives underway to increase the production of DME

from coal. In 2002 the government of China authorised construction of a plant with the

capacity to produce 830,000 t/year for domestic use, in the Ningxia region (Jun et al, 2003).

The authors show that the polygeneration of synthetic gases produced by the gasification of

mineral coal, can supply more competitive liquid fuels, reaching costs of 20 USD per barrel

or less. The system of polygeneration based on gasification may produce a variety of

chemical and energy products, as presented in Figure 4.

Figure 4: Modernisation of the use of coal and bio-mass in the production of DME in China

Source: Jun et al, (2003).

Inputs • Mineral coal • Heavy oils • Petroleum residues • Biomass • Natural gas

Short term Means End uses • Electricity • Steam • City gas • Gasoline/diesel

mixture • DME

• Industrial • Transport • Residential • Agriculture • Commercial

Gasification (Production of synthetic gas)

Long term Means Usos finais • Electricity • Steam • Hydrogen • DME

• Industrial • Transport • Residential • Agriculture • Commercial

Pol

ygen

erat

ion

Development of Infra-struture

19

Solar cooker

In addition, there are various research efforts under way aimed at replacing the

inefficient use of traditional fuels with renewable sources such as solar power. Solar cookers

are used in small quantities in India, China, Kenya, Zimbabwe and Peru. There are different

kinds of designs for these cookers, but the most common is the solar box cooker. The box

cooker is a box made up of a metal plate for absorption of the energy from the sun’s rays, four

walls of reflective material and the pane of glass on top, which acts as the lid through which

the rays pass and enter the box.

In addition to cooking of foodstuffs in general, mainly in the rural area, the solar

cooker is also used for heating water and for drying agro-livestock products. It avoids

deforestation or the burning of fossil fuels, and does not release smoke, which is harmful to

the atmosphere. The problem is that the oven does not work on days of low solar radiation,

and in this case requires support from one of the conventional stoves. Its use requires a site

with a good level of direct solar radiation, free of shadows and/or a lot of wind.

2.3 Tests of efficiency in fuel consumption and production

2.3.1 Efficiency of stoves

Dutt and Ravindranath (1993) mention three standardised tests to measure the

efficiency of stoves: water boiling tests (WBT), controlled cooking tests (CCT) and kitchen

performance tests (KPT). In the WBT test, a predetermined quantity of water is slowly boiled

while recording the variations in the water temperature and the fuel consumption. The

efficiency of a stove is calculated from the ratio between the heat absorbed by the water in the

pot, Eabsorbed (including any water evaporated in the process, Elatent) and the higher heating

value of the fuel23 (HHV) as presented in Equation i.

PCSEE latentabsorbed +=η Equation i

In the CCT tests, various stoves are tested in the preparation of a typical regional meal.

Comparison is made between various stoves, in relation to the quantity of energy consumed

23 Quantity of heat released by the complete combustion of a volume or mass unit of a fuel, when burned completely at a certain temperature, with one taking the combustion products (by cooling) to the temperature of the initial mixture, at which the water vapour is condensed and the heat recovered.

20

(in MJ) and the mass of the meal prepared in kilograms. Since these tests are carried out

under controlled conditions, they do not present the cooking conditions found in practice.

Accordingly, they do not reflect actual consumption of fuel, since it is unlikely that the stoves

get used in conditions which are similar to those in these tests.

The TDCs are the tests carried out in order to evaluate fuel consumption in a certain

number of homes as selected according to the statistical criteria, normally 100 or more

samples. The results of these tests consist in the quantity of energy consumed per person per

day, in MJ.

In evaluating the performance of charcoal stoves, Dutt and Ravindranath present results

of WBT tests for twelve kinds of stoves, carried out by Earnst Sangen and Piet Visser of the

Technological University of Eindhoven in the Netherlands. According to the authors, the

majority of the stoves shows efficiency greater than 40% in the high power test, as presented

in Table 5. The high power test is performed by the heating and boiling of water for thirty

minutes, controlling the power by adjusting the air flow in the combustion chamber. In the

low power TFA test, water is slowly boiled for sixty minutes, with a reduction of the air flow

in the combustion chamber.

Table 5: Performance characteristics of charcoal stoves in nine countries

Power [kW]

Ratio of CO/CO2 in

the combustion

gases

Stove

Damper to control the supply of

combustion air

High Low Eff

icie

ncy

[%]

High Low

Time to boiling point

[minutes]

DUB 9 – Burundi Yes 2.0 0.9 43.1 0.12 0.10 40 Efficient stove – Haiti Yes 2.0 0.6 45.6 0.12 0.15 35 Traditional stove – Ethiopia No 0.9 - 43.0 0.12 - 75 CEPPE – Ethiopia No 2.5 - 45.1 0.10 - 25 Sakkanal - Senegal Yes 2.4 1.5 29.3 0.16 0.13 60 Feu Malgache - Sahel No 1.8 - 29.2 0.12 - 65 Coalpot efficient stove Yes 3.5 1.2 25.0 - - 25 Traditional stove - Sudan No 1.7 - 41.5 0.14 - 55 Traditional bucket stove - Thailand Yes 3.6 2.0 45.0 0.10 0.06 25

Efficient bucket stove - Thailand Yes 4.0 0.8 48.6 0.04 0.06 25

UNICEF stove – Kenya Yes 3.5 1.1 37.1 0.05 0.09 30 KENGO stove – Kenya Yes 2.8 1.6 45.2 0.08 0.07 30 Source: Sangen and Visser (1986) in Dutt and Ravindranath (1993)

21

In general, the thermal efficiency of stoves increases progressively in the following

order: woodfuel, charcoal, kerosene, LPG and electrical power (Reddy (1997) and Kammen

(1995), in WEC (1999)). The thermal efficiency of various combinations of stoves and fuels,

varies significantly due to the different methods of measurement of efficiency, as presented in

Table 6.

Table 6: Average efficiencies24 of combinations of stoves and fuel

Efficiency [%] Fuel Stove kind/construction Laboratory Field

Acceptable

Three-stone woodfire (clay pot) - 5-10 7 Three stones (aluminium pot) 18-24 13-15 15 Traditional open oven - 3-6 5 Improved mud/clay 11-23 8-14 10 Bricks 15-25 13-16 15

Woodfuel

Metal and portable 25-35 20-30 25 Mud/clay 20-36 15-25 15 Charcoal Metal with ceramic fireplace 18-30 20-35 25 With wick – multi 28-32 25-55 30 With wick – single 20-40 20-35 30 Kerosene Pressurised 23-65 25-55 40 A hot plate 55-80 55-75 65 Electricity Pressure cooker - 85 -

Source: Kammen (1995), cited in WEC (1999).

Studies on overall efficiency25 of these combinations of fuels and stoves, however,

show that there is an exception in this efficiency sequence, as presented in Figure 5. Taking

into account the efficiency of production/processing, transmission and end (thermal) use of

each one of the fuels, the overall efficiency of the charcoal and electric stoves is relatively

lower than the thermal efficiency of these fuels (UNDP (2002) and Reddy (1997)). There are

great losses of energy in the production of charcoal and in the generation of electrical power

based on fossil fuels and mineral coal. For example, when using electrical power generated by

a coal-fired thermal power station, overall efficiency is only 20%.

24 The efficiencies and performances of the stoves, both in laboratories and in practice, are more variable than

those indicated here. There are various factors which affect efficiency, such as stove size and kinds of pots, climate, quality of the fuel and cooking method. For example, in relation to thermal efficiency, aluminium pots are two times more efficient than the traditional ones made of clay.

25 Overall efficiency refers to the product of the efficiencies of production, transport/transmission and consumption

of the fuel.

22

Figure 5: Variations in overall efficiency by type of stove

Hydro

CharcoalCo-generationDiesel

0

20

40

60

TEA TRA TL TCV EL ECV QM QP GLP EE

Ove

rall

effic

ienc

y [%

]Efficiency of conversion into useful energyOverall efficiencyOverall efficiencyOverall efficiencyOverall efficiency

Where:

TD, AR, TF, TCS: traditional stoves fired from dung, agricultural residues, firewood and charcoal; EF and EC: efficient stoves fired by firewood and charcoal; KW and PK: kerosene stove with wick burner and with pressurised kerosene; LPG and EP: gas stove and electrical hot plate stove. Source: Reddy (1997) and own estimates.

2.3.2 Efficiency in the production of charcoal In the production of charcoal,26 the largest quantity of energy is that used in the process

of carbonisation of the wood. It was observed in Rwanda and Madagascar that maximum

charcoal production efficiency was 9% (var der Plas, 1995). Taking into account as well the

low efficiency of charcoal stoves, the use of that coal becomes more inefficient than the direct

burning of wood, seeing that it increases the consumption of woodfuel by three to four times,

for the same quantity of useful energy produced. The yield from kilns in the production of

charcoal is given by Equation ii below.

%100][][

][[%] ×

−=

kgunburntpartkgusedwoodkgproducedcharcoal

Yield 27 Equation ii

The energy efficiency of a kiln is calculated as the ratio between the energy content of

the charcoal produced, and the energy content of the wood used, as presented in Equation iii.

%100][

][[%] ×=

JusedwoodtheincontainedenergyJproducedcharcoaltheincontainedenergy

Efficiency Equation iii

26 Charcoal production (“carvoejamento”) refers to the production of charcoal in which a carbonisation process

occurs by which the wood is submitted to thermal treatment at high temperatures, in a controlled reducing atmosphere.

27 The part of the wood not transformed into charcoal.

23

Dutt and Ravindranath (1993) show that in Thailand the brick beehive kiln, made out of

bricks in the shape of a beehive, is the most efficient of all of those presented in Table 7,

producing high-quality charcoal with lower costs.

Table 7: Comparison of efficiency and economy in the production of charcoal in Thailand. Construction Production costs

Type of kiln Volume [m3]

Costs [USD]

Yield [%]

Thermal efficiency

[%]

[USD/ tonne]

[USD/ GJ]

Traditional Clay mound 0.7 - 31.1 50.9 145 4.99

Mobile Tonga 0.2 13 22.7 36.0 403 13.91 Double drum 0.4 30 23.9 38.7 173 5.96

Permanent Modified Brazilian kiln 8.3 137 34.5 55.1 90 3.11 Hot tail 0.5 22 33.3 47.6 149 5.14 Mud beehive 7.2 38 32.0 44.8 101 3.49 Brick beehive 1 8.3 218 39.6 60.6 82 2.83 Brick beehive 2.3 2.0 105 37.5 62.5 95 3.26

Note: All costs are in 1989 USD. Source: Dutt and Ravinandranath (1993).

Three kinds of kilns are commonly used in Brazil: hot-tail, circular brick and

rectangular, with recovery of tar in the following proportions: 85%, 10% and 5% respectively.

The Brazilian kiln with tar recovery is the most efficient, with a yield of 36.4% and energy

efficiency of 57.1%, as presented in Table 8. This table also presents the characteristics of the

traditional kiln from Kenya, which is most common in the east Africa region.

Table 8: Comparison of kiln yield in charcoal production in Kenya and Brazil Charcoal production (“carvoejamento”) (%) Kiln Time

(hours) Yield Carbonisation Energy efficiency Traditional kilns

(Kenya) 5.0 – 10.0 21.6 – 34.2 36.7 – 58.2 33.9 - 57.4

Hot tail (Brazil) 3.29 34.1 52.1 46.1 Circular brick (Brazil) 1.88 28.7 50.4 40.3 Rectangular with tar

recovery (Brazil) 3.25 36.4 68.9 57.1

Source: Pennise et al. (2004).

The rectangular kilns, also equipped with a vapour condensation system, are the most

advanced in use at the present time in Brazil (CENBIO, 2004). The other kind of kiln, in a

cylindrical shape, the circular brick, has a small production capacity, is not mechanised and

24

lacks the tar recovery system. Masonry kilns, in the traditional shape and with a yield of

approximately 25%, still continue to be the most used in the charcoal works.

2.4 Consumption of traditional fuels and its side effects

In addition to having nearly zero costs, traditional stoves and fuels produce smoke and

soot which get deposited on the utensils, walls, ceiling, people and pots (Goldemberg, 2003).

For example, during the burning of firewood in a traditional stove, the resin contained in the

firewood is vaporised, generating strong flames. However the resin does not burn completely,

and consequently it ends up being deposited in the form of tar on the internal walls of the

oven and/or on the bottom of the pot. The remainder, in the form of vapour, leaves the oven

as smoke, along with the particulate matter and other combustion gases. The supply is limited

of sufficient air for all of the vaporised resin to react chemically with oxygen, due to the rapid

combustion in a short space of time.

The smoke arising from the burning of fuels contains air pollutants which have an

adverse effect on health and the environment (Hinrichs and Kleinbach, 2003). These

pollutants exist in the form of gases, TSP or small droplets of liquid dispersed in the air

(called aerosols). In addition to this, the inefficient burning of the traditional fuels is one of

the causes of excessive use of woods.

2.4.1 Emission of greenhouse gases The gases emitted in greatest quantity by the consumption of cooking energy are the

following three: carbon dioxide gas, carbon monoxide and nitrous oxide. In addition, the

stoves emit high quantities of carbon in the form of incomplete combustion product (ICP),

methane (CH4) and non-methane organic compounds (NMOC). The emission of air pollutants

is around 22 Gt/year of carbon, according to Hinrichs and Kleinbach (2003). According to the

authors, 80% of all of the gases emitted into the atmosphere each year have their origin in

activities related to the production and consumption of energy.

Carbon dioxide gas, CO2

Considering the radiative efficiency and life-time28 in the atmosphere, CO2 gas is

responsible for 55% of all accumulated greenhouse gases (Floor and van de Plas, 1992). The

largest sources of CO2 emissions are the burning of fossil fuels and deforestation. Total CO2

28 The time that the gas remains in the atmosphere.

25

emissions arising from human activities in 1989 are calculated at around 5.8 to 8.7 Gt of

carbon, of which the fossil fuels contributed 71% to 89%, and deforestation 10% to 28%. As

discussed above, deforestation is the result of the increase in agricultural activities, industrial

logging and the commercial production of firewood and charcoal. The use for energy of bio-

mass coming from sustainable sources does not cause a net increase in CO2 in the

atmosphere. Nevertheless, even with reforestation which makes possible the absorption of the

gas, the bio-mass production and consumption cycle emits incomplete combustion products,

which increase the possibility of global warming (Pennise et al, 2004).

Given the predominance of bio-mass within the energy consumption of the developing

countries, the contribution of fossil fuels to CO2 emission is insignificant. In Senegal, for

example, CO2 emission per capita in 1992 by the other (non-residential) sectors was 0.01

t/year, while the residential sector produced 0.4 t/year, or a quantity forty times greater than

the other sectors (Floor and van de Plas, 1992).

Considering the sum of emissions during production, transport and end use, Bailis et al.

(2004) show that for each 1 MJ of useful energy, charcoal produces five to ten times more

emissions of CO2-equivalents than the direct burning of woodfuel, and five times more than

any of the fossil fuels, as presented in Table 9. The largest quantity of emissions is produced

during the production of charcoal, due to low efficiency in the conversion from wood to

charcoal. The CO2 emission factor for the Kenyan kilns varies between 1058 and 3027 for

each Kg of charcoal produced (Pennise et al, 2004). The rectangular Brazilian kiln has the

lowest CO2 emission factor, of approximately 543 g/kg, due to high efficiency and greater

control of the process.

Table 9: Emissions of CO2-equivalents in g-C released, for each 1 MJ of useful cooking energy Energy Production Transport End use Total LPG 8.5 0.6 35.4 44.5 Kerosene (with wick) 5.7 0.7 39.2 45.6 Traditional wood stove (eucalyptus) 0.0 1.1 22.6 23.8 Efficient wood stove (eucalyptus) 0.0 0.7 26.7 27.4 Charcoal 174.1 1.6 39.6 215.3

Source: Bailis et al. (2004)

26

The greenhouse effect and the potential for global warming

Carbonic gas, methane and nitrous oxide, amongst others, are known as greenhouse

gases because they allow the rays of the sun to pass through the atmosphere, and prevent the

heat from escaping back into space, in the same way as a greenhouse. The capacity to prevent

the dispersion of the heat depends on the concentration of these gases, and thus the greater

their concentration, the greater is the warming. In addition, atmospheric warming from

greenhouse gases depends on the life-time of the gases in the atmosphere. According to OTA

(1991), in Floor and van der Plas (1992), in 1991 the contribution of each one of the

greenhouse gases arising from human activities was as follows: CO2 (55%), various CFCs

(chlorofluorocarbons - 24%), CH4 (15%) and N2O (6%). The United States contribute 21% of

all of the greenhouse gases, with the rest having its origin in the countries of the OECD,

Eastern Europe and Russia (22%), China and Central Asia (7%) and other developing

countries (27%).

Global warming is the increase in the greenhouse effect due to human activities.

Carbon dioxide gas (CO2) and methane (CH4) are the main GGs which have the greatest

potential to cause global warming, as presented in Table 10. The global warming potential

(GWP) of a greenhouse gas is the equivalent quantity of CO2 which would cause the same

global warming effect, expressed in gigagrams of carbon dioxide equivalent (GgCO2). GWP

is calculated by Equation iv.

PAGii fmPAG ×= ∑ Equation iv

in which:

mi emission of greenhouse gas i in mass, Gg - carbon equivalent (GgC);

fPAG i GG warming potential factor i, following the IPCC’s methodology, equal to 1.56

and 280 for the gases CO2, CH4 and N2O respectively, over a twenty-year period

as presented in Table 10.

Table 10: Global warming potential (GWP) and continuance of the greenhouse gases in the atmosphere Global warming potential (GWP)

Gas

Average life in the

Atmosphere [years]

20 years 100 years 500 years

CO2 50-200 1 1 1 CH4 12±3 56 21 6.5 N2O 120 280 310 170

Source: IPCC (1996)

27

According to Table 10, over a period of 100 years methane possesses a warming

potential 21 times greater than carbon dioxide, which has the value 1 in the above-cited scale.

Although nitrous oxide (N2O) has an apparently small participation in greenhouse gases (6%),

it possesses a life-time of 120 years and a GWP 310 times greater than that of CO2. The

process of global warming tends to increase natural disasters such as floods, avalanches,

blizzards, hurricanes, tornados and storms.

2.4.2 Indoor air pollution It is believed that indoor air pollution has been an important issue ever since prehistoric

times, since humanity began to live in temperate climate regions, approximately 200 thousand

years ago. The cold climate obliged it to build and live in shelters, and to use fire for cooking,

heating and lighting. Ironically, fire, which made it possible for humanity to enjoy the

benefits of shelters, resulted in indoor air pollution, as is noted by the soot which one finds in

prehistoric caves (Albalak, 1997 in Bruce et al, 2002b).

Indoor air pollution is the greatest potential risk to health, since generally people remain

within houses during the greater part of the day (von Schirnding et al, 2000). Ezzati and

Kammen (2002) show that women and children are most harmed, because they remain for

greater periods of time inside the home and in the kitchen preparing meals. For example, in

Kenya women in the age range between fifteen and forty-nine years of age are most

responsible for the preparation of food, thus remaining approximately five hours inside the

home and close to the stove, as presented in Table 11. In this way, the effects of this pollution

are felt in common between children and women.

Table 11: Time exposed to pollution for different age groups in Kenya

Age group Amount of the time inside the home

Amount of time near the stove

Probability of preparing food

Women Men Women Men Women Men 0-4 0.43 0.44 0.20 0.20 0.00 0.00

4-14 0.40 0.26 0.23 0.13 0.39 0.02 15-49 0.54 0.24 0.38 0.06 0.98 0.11 50+ 0.39 0.30 0.24 0.13 0.27 0.19

Average 0.45 0.30 0.27 0.13 0.48 0.06 Source: Ezzati and Kammen (2002).

28

Indoor air pollution predominates in developing countries, as presented in Figure 6, and

its victims add up to more than one billion people (Goldemberg and Villanueva, 2003). This

kind corresponds to around 90% of all pollution. One observes as well that two-thirds of

exposure to the pollution take place in rural residences in the developing countries. In the

developed countries, concentrations of indoor air pollution are similar to the concentrations in

the open air (Reddy et al, 1997), caused mainly by the industrial and transport sectors.

Figure 6: Distribution of the population exposed to air pollution

%9 %21

%58

5 %

0.4%

1%

0.1%

5%

Urban outdoors Urban indoors Rural outdoors Rural indoors

Developedcountries

Developingcountries

Source: Reddy et al. (1997), adapted from Smith (1993).

Total suspended particles (TSP)

In the developing countries, residential consumption of solid fuels such as mineral coal,

firewood and charcoal, causes elevated risks to health due to the emission of particulate

matter. In the majority of these countries, the average levels of total suspended particles29

(TSP) exceed by as much as twenty times the standard levels recommended by the WHO.

Particulates may affect respiration, aggravate pre-existing cardio-vascular diseases, and

possibly compromise the body’s immune system. Smith (1993) presents the levels of

concentration30 of TSP related to cooking, as shown in Table 12, which also agrees with the

results of another research study carried out in Kenya by Ezzatti et al. (2000).

29 TSP are small substances, with a diameter of between 0.01 and 50 microns (10-6 metre). 30 The concentration of a particular pollutant in air is measured by means of the mass of pollutant found in a given

volume of air, and is expressed in micrograms per cubic metre of air, µg/m3.

29

Table 12: Indoor TSP concentration levels in the developing countries

Country Year Sample characteristics Levels of TSP (µg/m3)

Kenya 1999 during combustion 3,764

Three-stone cookfire not during combustion 1,346

during combustion 1,942

Efficient wood stove not during combustion 312

during combustion 823

Traditional charcoal stove not during combustion 388

during combustion 316

Efficient charcoal stove (KCJ)31) not during combustion 50

India 1982 Cooking for fifteen minutes Firewood 15,800 Dung 18,300 Charcoal 5,500

China 1987 Cooking with woodfuel – for 24h 2,600 (respirable particles)

Source: Smith (1993) and Ezzatti et al. (2000).

TSP emissions per quantity of useful energy in the pot also vary, in accordance with the

efficiency of the stove/fuel combination. Smith (2000) presents estimates of TSP per quantity

of useful energy produced, in various combinations of fuels and stoves, as presented in Table

13.

Table 13: Doses of TSP per quantity of useful energy produced

TSP Fuel [g/MJ of useful

energy] [g/kg of fuel]

LPG 0.0209 0.514 Kerosene 0.0239 0.516 Charcoal 0.5277 2.375 Firewood/traditional stove 0.3776 1.038

Source: Smith (2000)

There is no direct relationship between the quantity of fuel used, and the emission of

TSP. The emission of TSP depends, in part, on the kind of stove and on the ventilation of the

place where the stove is being used (Zhang, 1999). Increased ventilation may significantly

diminish the concentration of the particulate matter, as presented in Figure 7.

31 This refers to the Kenya Ceramic Jiko, an efficient stove which uses charcoal and is built out of ceramic material

in order to improve its thermal efficiency.

30

Figure 7: Variation in concentrations of particulate matter and in ventilation

0

510

15

2025

30

0 5 10 15 20 25 30 35Air exchanges per hour

Con

cent

rati

on o

f TSP

du

ring

coo

king

[m

g/m

3]

Note:

The concentrations reflect typical conditions in the use of charcoal at the rate of 1.5 kg/h, TSP emission factor of

2g/kg, cooking time of three hours, and volume of the kitchen of 40 m3.

Source: Smith (1987), in Wallenstein (2003)

PM10

Another important parameter of indoor air pollution is the respirable particulates with a

diameter equal or less than 10 microns, called PM10. The PM10 manage to reach the lowest

regions of the respiratory system, and may increase the seriousness of respiratory infections,

particularly increase frequency of chronic bronchitis and increased risk of lung cancer and

premature death (Ezzatti, 2000).

Daily exposure to PM10, also called exposure indicator (E) for a person, is calculated by

equation v

i

m

ii tCE ×= ∑

=1

Equation v

in which,

Ci concentration of PM10 in atmosphere i in [µg/m3]

ti period of time in atmosphere i, ∑=

=m

ii hourst

1

24 .

m number of atmospheres in which the person stays in one day.

Average exposure, Caverage per day, is calculated by equation vi:

31

24E

Caverage = Equation vi

Carbon monoxide gas, CO

CO is a colourless, odourless and toxic gas, mainly produced in the incomplete

combustion of a fuel when there is insufficient air. The human body’s senses do not detect

CO; thus the levels of pollution from CO may increase up to fatal levels, without manifesting

any sign like throat irritation or cough. CO passes via the lungs through to the bloodstream

and attaches to the haemoglobin, preventing it from carrying oxygen from the lungs to the

cells of the body.

Charcoal has the highest CO emission factor of all of the fuels, as presented in Table 14.

The production of charcoal from wood eliminates the greater part of the TSP, PM10 and

hydrocarbon emissions; notwithstanding, it does not eliminate the CO (Smith, 2000).

However, there exists a limited number of research studies on CO poisoning due to the

consumption of charcoal.

Table 14: Carbon monoxide gas emission factors by type of fuel used CO Fuel

[g/MJ of useful energy] [g/kg of fuel] LPG 0.6076 15.0 Kerosene 0.8186 18.0 Charcoal 61.13 275.0 Woodfuel/traditional stove 24.19 66.5

Source: Smith (2000).

Since CO poisoning interferes with oxygenation of the blood (chronic anoxia), this may

result in damage to the heart and brain, impaired perception and asphyxia. In smaller doses,

poisoning may cause fatigue, headaches and nausea (Malilay, 1999). People with cardio-

vascular or respiratory diseases, children, elderly persons and pregnant women, are high-risk

individuals for CO poisoning. The standard limit for CO pollution is a maximum of 10,000

µg/m3 (10 mg/m3) over eight hours and 30 mg/m3 for one hour. During the use of charcoal in

typical conditions in a 40 m3 kitchen, with consumption of 1.7 kg/h, an emission factor of 74

g/kg and air circulation of 5-20 times per hour, the CO concentration is estimated at around

528 mg/m3, 13 times greater than the standard recommended by the WHO (Zhang et al,

1999). The CO concentration depends on the volume of the kitchen and on the air ventilation,

as presented in equation vii.

32

)()(

tCSV

EFttC f ×−

×=

∂∂

Equation vii

where:

C CO concentration

F the rate of burning of the fuel [kg/h]

Ef CO emission factor of the fuel [g/kg]

T cooking time [h]

V volume of the kitchen [m3]

S rate of air exchange (circulation) in the kitchen [h-1]

The greater the rate of air circulation in the kitchen, the more the CO concentration is

diminished, as presented in Figure 8.

Figure 8: Variation in the concentration of CO from the burning of firewood.

Note: The firewood was used in a stove without a chimney, in a kitchen with variable air circulation. The cooking

time, t, was equal to zero on lighting of the firewood and t=60 when the fire was put out.

Source: Zhang et al. (1999).

The results obtained by Zhang et al. (1999) suggest that CO concentrations in study conditions

are typically less than those causing acute poisoning. Notwithstanding the alteration of some

33

parameters such as ventilation, volume of the kitchen and burning time of the fuel, could increase the

concentration to fatal levels. However, in this study it was concluded that the users are exposed to

sufficiently high levels to cause chronic poisoning, with concentrations above 30 mg/m3 over eight

hours.

Indoor air pollution standards and limits

In 1970 in the United States, as part of the efforts to combat the impacts of air pollution,

the law was instituted known as the Clean Air Act Amendments, which established a series of

ambient air quality standards in the United States, the National Ambient Air Quality

Standards, NAAQs. The NAAQS for six pollutants responsible for effects on human health

were to be met by the beginning of 1975. Amongst the gases included are sulphur dioxide,

nitrogen oxides and carbon monoxide. There are two kinds of ambient air quality standards in

the United States: primary and secondary. Primary standards are meant to preserve human

health, while secondary standards protect human well-being, including from the effects of air

pollution on the vegetation, visibility, etc., as presented in Table 15. Agreement on safe levels

for air quality is still difficult, due to complexity in the definition and in establishment of the

standards. There is a large variation in susceptibility of different persons to the different

pollutants, and as well there is no disease that may be caused solely by air pollution (USEPA,

2004).

Table 15: Ambient air quality standards in the United States. Pollutant Exposure time Primary standard Secondary standard

Annual 50 µg/m3 Particulate matter (PM10) 24 hours 150 µg/m3

Same as the primary

Annual 15 µg/m3 Particulate matter (PM2.5) 24 hours 65 µg/m3

Same as the primary

Annual 10 mg/m3 (9 ppm) Carbon monoxide 24 hours 40 mg/m3 (35 ppm)

None

Oxides of nitrogen Annual 100 µg/m3 (0.05 ppm) Source: US-EPA (2004)

Effects of indoor air pollution on health

The adverse effects of particulate matter on health, for example those of PM10, are

serious in the greater part of the developing countries, due to the increased consumption of

solid fuels and consequent indoor air pollution. According to World Bank (1993), indoor air

pollution is responsible for approximately half of all diseases caused by the dreadful domestic

environmental conditions in these countries. The number of research efforts on this matter is

34

relatively minor; however the available information shows that indoor air pollution causes

various diseases and infections, grouped into five categories and discussed below.

Acute Respiratory Infections (ARI): There is evidence of a causal link between poor

health and acute infections of the airways, caused by the burning of solid fuels (Ezzatti and

Kammen, 2002). Infections are the primary cause of morbidity and mortality amongst

children under five years of age, provoking a greater number of deaths than

undernourishment, diarrhoea or other childhood diseases like measles and mumps. The

diseases caused by these infections cause more than four million deaths per year amongst

children under five years of age, contributing 25% of all deaths in that age bracket (WHO,

1995 and Ezzati and Kammen, 2002). In India, the infections and diseases caused by indoor

air pollution are responsible for the death of 270 thousand children under five years of age

(Smith, 2000).

Van Horen and Eberhard (1994), presenting the situation in Zimbabwe, noted that the

risk of contracting a disease of the airways was five times greater in rural homes without

electrical power, than in urban homes with electrical power. Rural homes use firewood for

cooking and lighting, while the urban homes use electrical power for lighting and cooking,

along with other fuels such as kerosene and LPG, thus reducing indoor air pollution. Poorly

ventilated buildings, and the setting up of kitchens inside the homes, increase the seriousness

of the pollution. In Kenya, for example, the number of infections caused by pollution is

greater in the rural areas where the majority of the homes generally consists of small multiple-

use buildings. In these areas, the same room is used for cooking, sleeping and working, and in

many cases, the total internal volume of air is less than 40 m3 (Goldemberg, 2003).

Adverse effects during pregnancy: Women exposed to air pollution during their

pregnancy have a higher probability of losing the child before birth (stillbirth) or of the child

being born underweight. In Guatemala, for example, children born in homes where there is

use of bio-fuels weigh less than children born in homes with use of cooking gas (Saatkamp,

2000).

Chronic Obstructive Lung Disease (COLD) and other heart diseases amongst adults:

This is a disease which develops after a long exposure time to the air pollutants, and when it

happens in the developing countries, it is directly related to the burning of solid fuels.

35

Lung cancer: Beyond the presence of carcinogenic compounds in the smoke coming

from the burning of firewood, the relationship is still not proven between the burning of bio-

mass and pulmonary cancer. However, the greater number of cases of lung cancer amongst

non-smoking women in the underdeveloped countries, suggests that there is a relationship

between the two (Bruce et al, 2000). Smith et al, 1999 shows that the use of mineral coal for

cooking and space heating in China, increases the risk of lung cancer to people exposed to

pollution by a factor of three to nine.

2.4.3 Deforestation and degradation of the Earth Deforestation is a complex phenomenon which is harming the quality of life of current

and future generations. According to UNEP (2002), two-thirds of all countries, or one billion

people, are victims of the ecological, economic and social consequences of deforestation. The

causes of deforestation include climatic changes and human activities such as the collection

and use of woodfuel.

As it is in principle a renewable source of energy, the use of bio-mass may be the most

sustainable option of all. However, it has been proven that the use of firewood and charcoal is

related to deforestation, principally when the consumption of these fuels is greater than

reforestation. Considering the relationship between the consumption of bio-mass for energy

purposes and its non-energy uses, Kammen et al. (2002) remind us that one cannot conclude

that the residential consumption of bio-mass is the only cause of deforestation and

degradation of the earth. The authors insist that, on the contrary, deforestation is frequently

the cause of a shortage of bio-mass. Consumption of energy from bio-mass may, however,

increase the degradation of the earth in some cases, for example the harvesting of firewood

from a forest which is already degraded or completely unrecoverable. Its consumption in this

case may prevent the forest from recovering.

The biggest problem is when the supply of bio-mass to meet the demand for firewood

declines. In these cases, poor families return to using agricultural residues and dung in the

place of woodfuel, thus reducing the supply of fodder for animals and for soil protection. In

addition, the exorbitant consumption of bio-mass may even result in imbalance in biodiversity

36

and hydrology, especially when there is a preference or planting of certain species of woods

for energy use, instead of the natural forests and vegetation of the location (Kammen, 2002).

2.4.4 Definition of clean cooking energy Clean cooking energy is produced efficiently, generating fewer pollutant substances

such as CO2 and incomplete combustion products: CO, CH4, NMOC and TSP. This part

presents the classification of different combinations of stoves and fuels which are responsible

for pollution, in order of efficiency and of emission of combustion gases.

Less indoor air pollution

The burning of solid bio-fuels releases a greater quantity of CO2 and TSP per MJ of

energy produced, than the burning of the gaseous and liquid fuels (Kammen, 1995 in

Goldemberg and Johansson, 1995 and Zhang, 2000). In some cases, emissions from the bio-

fuel stoves are as much as fifty times higher than those from gaseous fuels. One concludes,

therefore, that all of the stoves which use gaseous or liquid fuels are relatively cleaner, as

presented in Figure 9. The lower the efficiency of the combination of stove and fuel, the

greater is the emission of particulate matter.

Figure 9: Variation in the quantities of emissions for different combinations of fuels and stoves.

0

20

40

60

80

B

PK

K-w

ick

LPG

L_t

m

L_3

s

D_t

m

C_t

m

KC

J

C_j

iko

Eff

icie

ncy

[%]

0.01

0.1

1

10

100

Em

issi

ons

per

usef

ul

ener

gy [

g/M

J]

Efficiency

CO

TSP

Note:

B: biogas stove; PK: pressurised kerosene stove; K-wick: kerosene stove with wick; LPG: LPG stove; L_tm:

traditional metal wood stove; L_3s: three-stone cookfire; D_tm: traditional metal dung stove; C_tm: traditional

metal charcoal stove; KCJ: efficient charcoal stove from Kenya; and C_jiko: traditional charcoal stove from

Kenya.

Source: Smith et al. (2000) and Zhang (2000).

37

Less environmental pollution

From the environmental viewpoint, Smith et al. (1998) show that the most important

parameters for evaluating the polluting potential of a given combination of stove and fuel, are

the indicators of the quantity of emissions (IQE), and overall efficiency in its consumption

(?). Above all, most important is the environmental index of the stove (EIS), which relates the

indicators of emission to overall efficiency in the use of the fuel, in equation viii.

( )[ ]IQEIAF −= 1ln η Equation viii

in which:

( )1/1 += kIQE Equation ix

in which:

k is the sum of weighted ratios of CO/CO2, CH4/CO2, CCONM/CO2 and TSP/CO2.

As well, overall efficiency is calculated by equation x,

ETCENC ×=η Equation x

In which ENC represents the efficiency of transformation of the energy contained in the

fuel (in the chemical form) into heat (thermal energy) by combustion, while ETC is the

efficiency of heat transfer to the pot (useful energy).

All of the parameters in equations v, vi and vii are obtained through emission tests for

the stoves. The combinations of stoves and fuels with higher EIS are the cleanest, and thus

they pollute the environment less. The greater the EIS value, the less polluting the

combination of stove and fuel is. All of the stoves operating with gaseous or liquid fuels have

greater overall efficiency and are relatively cleaner, as presented in Figure 10.

38

Figure 10: Variations between efficiency and the Environmental Index of the Stove (EIS).

TRHTCS

EF

TFKW

PKLPG

Biogas

0.001

0.01

0.1

1

10

100

5 15 25 35 45 55 65

Overall efficiency [% ]

Env

iron

men

tal I

ndex

of

the

Sto

ve

Note:

PK: pressurised kerosene stove; KW: kerosene stove with wick burner; TCS: traditional charcoal stove; TF:

traditional wood stove; EF: efficient wood stove; TRH: traditional rice husk stove; ERH: efficient rice husk

stove; TD: traditional dung stove; ED: efficient dung stove.

Source: Smith et al. (2000).

Combining the results from Figure 9 and Figure 10, one concludes that biogas is the

cleanest fuel of all, followed by LPG and pressurised kerosene stove, according to the energy

ladder discussed in Section 2.5.1. In general, all of the gaseous fuels qualify as clean cooking

fuels.

2.5 Energy transition and fuel substitution

Energy transition refers to an increase in the consumption of modern fuels and a

decrease in the consumption of traditional fuels like bio-mass. In general terms, the transition

process is driven by socio-economic development and the improvement in household income.

Energy transition may reduce per capita consumption of energy and the quantities of air

pollutants emitted, due to the introduction of more efficient technologies. As it is an

evolutionary process, energy transition occurs over a long time period. For example, between

1986 and 2002 in Brazil, the contribution of woodfuel to home energy consumption declined

from 48.5% to 28% (BEN, 2003). On the other hand, LPG participation increased, replacing

woodfuel and charcoal by the year 1999. After 1999, woodfuel participation began to increase

and that of LPG to decline, as presented in Figure 11.

39

Figure 11: Trend in the consumption of cooking fuels in Brazil between 1973 and 2002

0 %

20 %

40 %

60 %

80 %

100 %

1973

1976

1979

1982

1985

1988

1991

1994

1997

2000

Per

cent

age

cons

umpt

ion

0

200

400

600

800

1000

Con

sum

ptio

n [P

J]

LPG

WoodfuelOthers

FinalenergyUsefulenergy

Source: BEN (2003)

Since the energy crisis of the 1970s, efficient stove programs have been carried out to

reduce the consumption of bio-mass in the developing countries, initiated by their

governments or by the international organisations. The crisis, also known as the oil shock,

prevented poor families from climbing the energy ladder (Section 2.5.1) to the fossil fuels like

LPG and kerosene; consequently, dependence on bio-mass increased even further (Ezzatti et

al, 2000). The multiple benefits of efficient stoves in the reduction of indoor and general air

pollution, drove the design and implementation of the efficient stove programs.

2.5.1 Theory and criticism of the “energy ladder” model The “energy ladder” model is used to describe the dynamics in choosing home cooking

fuels. Baldwin (1986), Smith (1987), Hossier & David (1988), Leach & Means (1988) and

Leach (1992) in Masera et al. (2000) explain the principal hypothesis of the model: to the

extent that as families improve their living conditions, they abandon the use of traditional

fuels and exchange them for the more efficient, more convenient and less polluting ones.

The various options for supplying energy are characterised by price, efficiency,

cleanliness and convenience of use. Each one of the characteristics correlates to the others in

some way: the traditional fuels are the most polluting and least convenient in their use, for

example; while the modern fuels are the cleanest, most efficient and convenient, they are also

the most expensive. Figure 12 presents these fuels and their relative positions on the energy

ladder. Moving to the right, there is increased cost and efficiency and also an increased level

of marketing of fuels and stoves. Woodfuel, dung and agricultural residues represent the step

40

in the lowest position on the ladder. Charcoal, mineral coal and kerosene represent the next

steps on the ladder and, in the highest position are located electrical power and LPG.

Figure 12: Comparison of stove efficiency and initial costs in the energy ladder model.

0

20

40

60

80

TD AR TF TCS EF EC KW PK LPG EP

Increasing affluence >>>

Eff

icie

ncy

[%]

0

20

40

60

80

Init

ial c

ost

[USD

] Efficiency

Initialcosts

Note:

TD, AR, TF, TCS: traditional dung, agricultural residue, firewood and charcoal stoves; EF and EC: efficient

firewood and charcoal stoves; KW and PK: kerosene stove with wick burner and pressured kerosene stove; LPG

and EP: gas stove and electrical hotplate stove. The efficiencies refer solely to the consumption of the fuels, and

the initial costs are costs for acquiring the stoves.

Source: Reddy (1997)

The energy ladder model is characterised by its simple form of presenting the

relationship between fuel choice and user’s income level. The model presents an idea that

climbing the ladder is associated with the abandonment of the fuels and technologies which

were used previously. However, reality is not in line with this progressive and unidirectional

transition as suggested in this model.

More recently other opinions have arisen to explain the trend to energy transition in

homes, notably the work of Masera et al (2000). The authors emphasise that the energy

transition is a function of four essential factors: (a) costs and accessibility; (b) efficiency and

convenience of use; (c) culture; and (d) quantity of emissions per quantity of energy

produced. Switching fuel, therefore, is an interactive process in which some factors push the

user toward the use of modern fuels, and others pull him/her back to the use of traditional

fuels. It is a bi-directional process: in the same way as the consumer can climb the energy

ladder, he/she can also go down, once again using woodfuel and other traditional fuels in

certain situations.

41

In general terms, woodfuel is rarely completely replaced, even with the availability of

the modern fuels. For example, Reddy (1997) shows that the use of bio-mass in Pakistan and

Vietnam is widespread, for both the poor and rich classes, in proportions of 91.4% and 60.9%

respectively. In the shanty areas of Campinas, Jannuzzi (1991) shows that woodfuel still

corresponded to a significant portion of domestic consumption for cooking, despite the

widespread presence of LPG. Close to 40% of homes used firewood, both in stoves especially

built to this end, as well as in improvised stoves.

2.5.2 Determinant factors in the choice of fuel The choice of a certain kind of fuel is complex and dynamic. Davis (1998), citing the

work of Leach (1987) in a research study in south Asia, lists four of the most important

factors in the choice of fuel. They are: family income, relative prices of the fuels, costs of

stoves and availability of fuels. In some cases, the choice of fuel is made in such a way that it

ensures the security of supply of another energy source. For example, Jannuzzi (1991)

highlights that wood stoves are used in the shanty areas for heating of water for the bath,

because the use of electric showers causes falls in the voltage and blowing of fuses, and

consequently electrical power service interruptions in the residential units. In this case, the

use of firewood was a strategy to minimise risks in the electrical power supply, which is

insecure in the shanty areas due to illegal connections and to the low technical standard of the

installations. Another example occurs in the Philippines, where it shows that firewood and

charcoal are kept in stock as emergency fuels, in the event of a shortage of LPG (WEC,

1999).

The price of the fuels is also important in the choice. Davis (1998) shows that the use of

multiple fuels is widespread in low-income homes, as a budget strategy within the household

economy. The low-Income population is very sensitive to price variations. When a given kind

of fuel becomes more expensive, firewood is the favourite replacement. In the preparation of

meals which consume more energy, the cheapest options are chosen. Jannuzzi (1991) shows

that the low-Income population prefers to use the wood stove as a means for cooking beans

and other foodstuffs with long cooking times, because it is cheaper than use of the gas or

electric stove. In some cases, however, price is not a determinant in the choice of fuel. In a

town in Sierra Leone, two-thirds of the families do not switch from firewood to other fuels,

due to the ease which the wood stove offers in preparation of the meals which are typical of

the region (WEC, 1999).

42

The choice also depends on fuel availability. For example, in the cities of Joe Slovo and

Khayelitsha in South Africa, despite being expensive, kerosene is used by the majority of

homes, due to its availability and sale even in smaller quantities (Mehlwana and Qase, 1996).

Leach and Gowan (1987) in Davis (1998), reviewing various research efforts on cooking

energy, summarise the factors which influence the supply and demand of a given fuel, in

Table 16.

Table 16: Determinant factors in the choice of fuel Supply Demand

• Fuel price and availability • Time and work required in the collection

and use of the fuel • Location: urban or peri-urban • Fuel characteristics, and preferences

• Household income • Number of persons in the family • Climate • Culture (diet, way of preparing meals) • Stove costs and efficiencies

Source: Leach and Gowan (1987), in Davis (1999).

2.5.3 Dissemination of efficient bio-mass stoves and kilns

The use of efficient stoves was considered as the ideal measure for conserving energy

and reducing deforestation and the emission of air pollutants. The majority of the efficient

stove programs had expectations of reaching 75% or greater thermal efficiency, based on the

results of laboratory tests. However, the greater part of them failed in technical and social

terms, because they did not look at cooking conditions in real situations (WEC, 1999).

It was also proven that the use of efficient stoves, nevertheless, does not necessarily

reduce the consumption of cooking fuels, because the savings realised by the efficient stoves

is normally neutralised by the new increase in consumption. Dutt and Ravindranath (1993)

show an example of this situation in Thailand, in which when the family manages to

economise in energy expenditure, costs increase in other necessities, for example, in the

purchase of more foods which require more energy in their preparation. In many countries,

the informal sector is the one most involved in the production and marketing of these stoves.

Nevertheless, limitations in the informal sector in terms of capacity, quality and production

costs hold back greater dissemination of these kinds of stoves (Eberhard, 1992).

The development and dissemination of efficient bio-mass stoves began in the eighties.

Executed by governmental and non-governmental agencies, these programs aimed at

43

accelerating the energy transition toward cleaner fuels and technologies at more affordable

prices. Some examples of these programs, in China, India and Kenya, are presented below.

National Efficient Stoves Program in China

At the beginning of the nineteen-eighties the Chinese government started the National

Efficient Stoves Program, NESP, having as its mission to disseminate efficient bio-mass and

coal stoves for cooking and heating. The program, administered by the Ministry of

Agriculture of China, had installed 130 million efficient stoves at the beginning of the

nineteen-nineties, at the time of its conclusion (Smith and Zhang, 2004). From that point on,

the Ministry directed its attention to supporting companies that manufactured stoves, and in

the middle of the nineties, it introduced the certification and standardisation system for stoves.

At present, the marketing of the efficient stoves is conducted by the private sector and

monitored by municipal administrations. During the period from 1982 to 1999, the Chinese

stove program had installed 175 million bio-mass stoves in rural homes in China (UNDP,

2002). Smith and Zhang (2004) estimate that in 1998, from amongst 236 million rural homes,

185 million had efficient bio-mass or coal stoves. It is calculated that in the last twenty years,

possibly 90% of all efficient stoves in the world have been installed in China.

An efficient stove in China cost around 10 USD, with an indirect subsidy from the

government of 0.84 USD (UNDP, 2002), this being equivalent to 0.5% of the average income

per year of the families in the rural areas (Smith, 1993). The total cost of disseminating 110

million efficient stoves between 1983 and 1989 was approximately 1 billion USD, with only

16% of the amount (158 million USD) being invested by the Chinese government—in

training, promotion, monitoring and subsidies for low-income families (Geller, 2003). The

Chinese program installed research and development units and supported the rural firms in the

manufacture, installation and maintenance of efficient stoves, benefiting from the experience

and wide infrastructure previously developed by the program for dissemination of

biodigestors and for installation of small hydro-electric power stations (UNDP (2002), Geller

(2003)). The majority of the efficient stoves has saved bio-mass by as much as 25% and has

improved indoor air quality for the users, states Smith (1993) in Geller (2003).

National Program on Improved Chulhas of India

The National Program on Improved Chulhas (NPIC) was launched in India in 1984,

aiming to reduce the demand for fuels coming from bio-mass, through improvement in the

44

efficiency of combustion of the traditional stoves, called “chulhas” (Hanbar and Karve, 2002).

The NPIC has components of research and development, technical and entrepreneurship

training, raising of awareness and publicity. The NPIC had as its target to distribute efficient

subsidised stoves to each residence, as part of raising the awareness of Indian society as to the

benefits of improvements in efficiency in bio-mass consumption. The idea was that the

benefits would consist in the incentive for the homes to buy and use efficient stoves, even

without a subsidy from the program. An efficient chulha stove costs around 4.50 USD, of

which the government subsidises half of the price.

In 2001 the program had disseminated efficient stoves to only 32.77 million homes

(27%) from amongst the estimated 120 million homes in India. Today, only one third of

installed stoves work, and the majority of them did not manage to save energy or eliminate

smoke from the kitchens (UNDP, 2002). There is no information on the degree of awareness

achieved, but the program created a good research and development infrastructure and trained

entrepreneurial manpower in various parts of India (Hanbar and Karve, 2002).

Dissemination of the Kenyan ceramic stove

In Kenya at least 700 thousand efficient stoves, the KCJ (Kenya Ceramic Jiko) are

being used in more than 50% of urban homes and 16% of the rural areas (UNDP, 2002). The

dissemination programs for these stoves began in 1982. The dissemination of efficient KCJ

stoves is considered one of the success stories in the Africa region. At present the

manufacture and marketing of the stoves employ around 200 groups of artisans, and

production is at a rate of 13 thousand units/month. The methodology for dissemination of

these stoves was replicated in many other African countries, such as Tanzania, Sudan,

Uganda, Zambia, Rwanda and Burundi (Kammen, 1995). With the growing expansion of the

market, competition between groups of manufacturers and advances in technological

innovations, the unit price of the stoves fell from 15 USD to 1-3 USD, depending on the

stove’s size, design and quality.

The KCJ stove, in Figure 13, which uses charcoal, is composed of a ceramic part which

acts as a heat insulator, thus making possible the transfer to the pot of 25% to 40% of all heat

produced by the burning of the charcoal. The ceramic part absorbs 20-40% of the heat, and

10-30% is emitted along with combustion gases. The KCJ is most common in the urban areas;

its use in the rural areas is limited due to the high costs. A KCJ stove has a life-span of 1.5 to

45

2 years and costs around 5 USD, which is relatively more expensive for the low-income

families (Ezzatti and Kammen, 2002).

Figure 13: A Kenyan ceramic stove (KCJ)

Pot support Oven (ceramic) External part (metal) Grate Air inlet (Ash removal)

Efficient kilns in the production of charcoal in Senegal

The “Casamance” efficient kiln was introduced into Senegal in the 1970s, at a time

when there was greater concern with deforestation. This kiln was developed as an improved

version of traditional kilns, with the objective of reducing deforestation. However, the idea of

efficiency was not well received by the charcoal traders: improvement in the production of

charcoal and other long-term investments, like the reduction of deforestation, did not interest

them because it compromised their economic subsistence. (Denton, 2004). The author

highlights that with greater availability of wood, there is literally no convincing reason for the

producers of charcoal to change the current production technology. The author concludes that

the producers will look at the importance of efficient technologies, if and when wood

becomes a marketed commodity.

2.5.4 Programs of subsidies to kerosene and LPG prices.

Subsidies are considered to be any intervention in order to maintain the prices of fuels

(or other services), or energy production costs, below true market prices. The subsidy may be

applied on the supply side or on the side of consumption of the fuel, or on both. This part

seeks to evaluate the importance of subsidies in the dissemination and use of the commercial

fuels, mainly LPG and kerosene.

“Butanisation” program in Senegal

The objective of the LPG program in Senegal was to replace part of charcoal

consumption by LPG in the urban areas. Sokona (2001) highlights that the program began in

1974 with the removal of Customs duties on the importation of all items connected to LPG.

Consumption grew from 3,000 tonnes in 1974, to 15,000 tonnes in 1987. By 1987, even with

46

a Customs rate of zero, the program still hadn’t managed to attract a greater number of

consumers, as presented in Figure 14.

Figure 14: Trend in LPG consumption in various market segments in Senegal, 1974 to 1999.

Note

Total, popular: is the consumption of LPG in “popular” bottles of 2.75 kg and 6 kg.

Source: Sokona (2001)

In 1987, in order to further motivate the consumption of the gas and to keep end prices

constant, the government introduced the policy of rationing consumption of forest resources,

and subsidising LPG prices. The government increased the stumpage fee, limited production

of charcoal solely to certain specific areas, and increased the end price of charcoal (Denton,

2004). Three price structures were established, for the LPG marketed in bottles of 2.75 kg, 6

kg and 38 kg. Each one of the structures included components of refinery cost, port taxes,

stabilisation (subsidy), distribution margins and value-added tax (VAT). LPG was subsidised

only in smaller bottles (popular bottles of 2.75 kg and 6 kg) for residential use. One of the

results of the application of the subsidy, was an abrupt increase in consumption of LPG in

popular bottles of 2.75 kg and 6 kg, and in general, consumption increased from 15 thousand

tonnes in 1987 to 100 thousand tonnes in 2000, as is presented in Figure 14.

In 1998, foreseeing the liberalisation of the country’s oil sector, the government

approved a law which required monthly review of prices and the gradual removal of the

subsidy, which was at a rate of 20% by the year 2002. The Department of Energy of Senegal

estimates that the butanisation program had as its result, a savings of 70 thousand tonnes of

wood and 90 thousand tonnes of charcoal. In short, consumption of wood declined by 700

47

thousand m3, equivalent to 15% of the country’s current woodfuel consumption (Daton,

2004). Today, 80% of homes in Dakar, the capital of Senegal, use LPG for cooking, and the

butanisation program in this country is considered a success in the marketing of LPG in the

urban areas in Africa.

Nevertheless, rural consumers were excluded and the reduction of prices for LPG did

not benefit them (Daton, 2004); on the contrary, the rural population still continues to use

woodfuel and charcoal. The high costs of gas stoves and LPG in the rural areas confirm the

impracticality of consumption in these areas, where the population faces financial difficulties

even to buy kerosene for lighting. The cross-subsidy policy imposed taxes on the prices of all

fuels derived from petroleum, including kerosene. Thus, poor consumers in the rural areas

unfairly pay more on their purchases of kerosene, in order to favour LPG consumption in the

urban areas.

Subsidy to LPG and kerosene in India

In India, the government still subsidises the price of LPG and that of kerosene sold by

state enterprises (Gangopadhyay et al, 2004). Private enterprises do not sell subsidised LPG;

even so, they are active in some regions where the market is favourable. LPG is considered a

fuel for high-income-level families; for that reason, per capita consumption is greater for the

rich families than for the poor ones. As presented in Figure 15, the rich families are

responsible for 50% at all consumption in the rural areas, while this proportion is 63% in the

urban areas where the gas is used most amongst the five highest-ranked levels in terms of

volume of expenditures. One observes that the penetration of LPG is more concentrated in the

urban areas, where nearly all of the families have access to the fuel. As such, urban families

benefit more from the subsidy on the gas and this shows that the subsidy mechanism is highly

inefficient in improving the well-being of the poor, and in the reduction of consumption of

traditional fuels in India.

48

Figure 15: Consumption of LPG by social classes in India.

0

10

20

30

40

50

1 2 3 4 5 6 7 8 9 10

Volume of expenditures

Con

sum

ptio

n [%

]

RuralUrban

Source: Gangopadhyay et al. (2004)

Kerosene directed to residential consumption is also subsidised in India. Nevertheless, a

large part of it is illegally diverted for consumption in other sectors, mainly in the adulteration

of gasoline and diesel, within the automobile sector (Gangopadhyay et al, 2004). According

to the authors, 50% of subsidised kerosene is diverted in this way. In 1999-2000 the

government of India invested 1.56 billion USD as a subsidy on kerosene prices; however,

only half of this amount (0.78 billion USD) benefited residential consumers. The great

difference between the price of diesel and the price of subsidised kerosene, constitutes the

reason attracting a greater number of people into this fraud. Between 1999 and 2000 the price

of diesel was three times higher than that of kerosene: the average price of diesel varied

between 0.20 and 0.24 USD/litre, while the price of kerosene varied between 0.06 and 0.08

USD.

Subsidy on the price of LPG in Brazil32

Around 98% of the 46.5 million homes in Brazil have access to LPG, and its

penetration in the rural areas is around 93% (IBGE, 2002). Domestic use of the gas, marketed

in bottles of 13 Kg, began in 1937, and its production in Brazil began in 1955. In 2002

production was around 8,902 million m3, and the difference between demand and production

of approximately 40%, was made up from imported LPG. LPG consumption per capita is

around 31.35 Kg/year, equivalent to 1,488 MJ/year. The most common form of marketing is

that of bottling in 13-Kg bottles. More than seventy million empty bottles of this kind are

estimated to be in circulation throughout the country. 45-Kg cylinders of gas are also widely

marketed, mainly for use in the commercial sector. Other recipients with different capacities

32 Section based on the article “LPG subsidies in Brazil: an estimate”, Jannuzzi G. D. M. e Sanga G. A., published in Energy for Sustainable Development Journal, v. III, nº 3, pp. 127-129.

49

may also be found, but in a much smaller number. The sale of LPG in bulk is carried out in

trucks and pressurised tanker trucks which directly fill the stationary bottles.

Residential consumption of LPG in Brazil hit its maximum amount in 2002 of seven

million tonnes (or the equivalent of ten million m3), which is equivalent to 280 PJ. Between

2001 and 2002, consumption declined by 5% (equivalent to 9.35 PJ), after two successive

years with growth of 3% and 4% (ANP, 2004). Consequently, the residential sector’s

percentage of participation in LPG consumption fell from 82% in 2001 to 70% in 2003. At

the same time, use of natural gas has been increasing in the last ten years in the residential

sector. There was growth of 600% in residential consumption of natural gas over the last ten

years, reaching the amount of 179 million cubic metres in 2002. Between 2001 and 2002

consumption of natural gas increased to 39 million m3, the equivalent of 1.4 PJ.

Historically, Brazil has for some decades practised the policy of cross-subsidy in the

marketing of petroleum derivatives, favouring low LPG prices. The price structure was made

up of four categories: price of production, royalties, taxes and distribution margins. The

amount of subsidy to LPG varied over time, as presented in Figure 16, which also contains

variations in the price of production—the refinery price. One observes that the percentage of

subsidy was at its maximum, in the amount of 50%, between October 1999 and February

2000, and was at its minimum in December 1998, with a value of -25%. In this month the

LPG consumer was paying 25% more than the price of production at the refineries. The prices

of petroleum derivatives in Brazil are readjusted periodically, in line with petroleum price

variations on the international market and the country’s price policies.

Figure 16: Variations in the price of production, refinery price and percentage of subsidy on LPG in Brazil between 1998 and 2001.

0

0.2

0.4

0.6

0.8

1

jul.9

8

okt.9

8

jan.

99

apr.9

9

jul.9

9

okt.9

9

jan.

00

apr.0

0

jul.0

0

okt.0

0

jan.

01

apr.0

1

jul.0

1

okt.0

1

Pri

ce [B

RL

/kg]

-30

-10

10

30

50

70

Subs

idy

leve

l [%

]

Productionprice

Price exrefinery

Level ofsubsidy

Source: Petrobrás (2004)

50

In May 2001, the prices of LPG were released, following up on deregulation of the

petroleum sub-sector (ANP, 2004). The price of a bottle of LPG leaving the refinery in Rio de

Janeiro, net of state-level taxes, was 9 reais (3.56 USD) in December 2001, 3.47 reais (1.37

USD) being subsidised, as presented in Table 17. The removal of the LPG subsidy in January

2002 increased the end price of the bottle by 6%. The price would have increased even

further, if not for the reduction of 25% in the production price at the refineries, following the

fall in the price of petroleum on the international market and the upward foreign-exchange

revaluation of the national currency (Petrobrás, 2004). In December 2002 the price of a

canister of LPG in Rio was 25.05 BRL, and the production costs, royalties and distribution

margin rose to 11.09 BRL (2.97 USD), 5.71 BRL and 8.74 BRL respectively. The distribution

margin percentage is around 50% of the end price.

Table 17: Price structure of the 13-Kg bottle of LPG and price liberalisation in January 2002 in Rio de Janeiro

January 2002 Components of the price December

2001 All consumers

Low-income consumers

Production cost 9.00 6.67 6.67 Royalties 3.76 3.36 3.36 Distribution margin 13.02 13.71 13.71 Subsidy (low-Income people have a gas voucher) -3.47 0 -7.50 End price 22.30 23.74 16.24 Subsidy (relative to the production costs and royalties) 27% 0 75%

Subsidy (in relation to the end price) 16% 0 32% Source: ANP/Petrobrás (2002)

Using information from Figure 16 and from Table 17, the percentage of subsidy is

estimated at around 30% of the price of the LPG at the refinery gate and 18% on its end price.

The annual amount of the subsidy is calculated, accordingly, as 18% of the end price of the

LPG. The amount of subsidy may be estimated by the use of the annual information on the

volume of sales and consumption. From 1973 to 2001, consumption of LPG increased four

times and the amount of the subsidy was estimated at around 8.23 billion USD at current

prices. Correcting for inflation and considering 2001 constant prices, the value of subsidy is

calculated at around 2.93 billion USD.

51

Considering consumption of useful energy per capita at 1 GJ/year (Section 2.1.1), LPG

consumption per capita is estimated at around 2 GJ/year33, or 40.32 Kg, equivalent to three

13-Kg bottles. Using historical data on LPG consumption in Brazil and the estimate of per

capita consumption, the average subsidy values per capita on the price of LPG are presented

in Figure 17. The subsidy amount per capita in 2001 is calculated at around 4.38 USD.

Figure 17: Trend in annual consumption of LPG [TJ], end price (current) and per capita subsidy, in Brazil between 1973 and 2001

Source: MME (2003) and own estimates

Since January 2002, when the subsidy was removed on the price of LPG, the Brazilian

government began to practice a social policy of support to the low-Income population via the

gas voucher, equivalent to 7.50 BRL/month (2.4 USD) on the purchase of LPG for domestic

use. Those who benefited from this program are families with a monthly income per capita of

up to one-half the monthly minimum wage34. In the year 2002 the federal government spent

650 million BRL (349 million USD in constant 2001 values) to finance the gas voucher,

benefiting 6.7 million families. This amount corresponded to 4.8% of the government’s costs

for social welfare programs. In the year 2003 the number of those benefiting from the

program increased to 7.9 million families, close to 20% of the population, and in that year the

subsidy amounted to 462 million USD in constant 2001 prices.

During the 2002 and 2003 period, the gas voucher program was equivalent to an

average subsidy of 16 USD per capita per year35. The total amount of the subsidy since 1973,

therefore, is the sum of 2.93 billion USD, 349 million USD and 462 million USD, which is to

33 The efficiency of the gas stove is considered to be around 50%. 34 The minimum wage approved in June 2004 is 260 BRL (83 USD) 35 Considering the average size of a low-income family of 3-4 persons.

0

100

200

300

400

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

Con

sum

o [P

J]

0

5

10

15

20

Pre

ço [U

S$/G

J],

Subs

ídio

per

cap

ita

[US$

]

Consumo

Preçocorrente

Subsídioper

52

say, 3.7 billion USD. The gas voucher program was launched to aid solely the low-Income

part of the population, which is highly affected by fuel price increases. The application of

subsidies for all LPG consumers, without distinction as to income, would be more expensive

and would be unnecessary for the already-established market.

2.6 Summary of the Chapter

Amongst poor families, food cooking represents the greater part of energy consumption,

oscillating between 90% and 100% of residential consumption. There are various kinds of

fuels used for cooking, such as solids (charcoal, woodfuel, coal), liquids (kerosene), gases

(LPG, biogas) and electrical power. Per capita consumption of cooking energy is constant at

around 1 GJ/year. In the majority of the rural areas, cooking energy, in the form of bio-mass,

is available without monetary cost, notwithstanding the fact that consumers pay for the energy

which they consume. Energy expenditures amongst poor families in the urban and semi-urban

areas represent up to 22% of household expenditures, although the ideal is that it be a

proportion of between 5% and 10%, as is spent by the rich families.

Energy consumption of woodfuel for cooking is responsible for only 7% of

deforestation; nevertheless, the greater concern for the time being is the growing consumption

of charcoal in the urban areas of Africa. The consumption and production of charcoal are

practised in ways which are still very inefficient, causing great pressure on natural resources

in the areas where the fuel is produced. LPG and kerosene consumption in the rural areas is

limited, due to the high costs and lack of infrastructure for their marketing. In addition to fuel

prices and family income, choice of cooking fuel depends on various other factors; it thus

becomes a dynamic and bidirectional phenomenon.

The quantity of indoor emissions due to the use of traditional fuels in inefficient stoves,

puts the user at high risk to his/her health. Liquid and gaseous fuels are relatively speaking

cleaner than the solids, because they emit lower quantities of CO2 and incomplete combustion

products such as CO and CH4. The burning of gaseous and liquid fuels is more efficient than

that of the solid fuels. For example, combustion of kerosene and LPG is 3-7 times more

efficient than combustion of firewood in traditional stoves.

The adverse effects of particulates, PM10 for example, as well as the environmental

impacts, justify the reduction of indoor air pollution. It is expected that these effects are

53

increased in the developing countries, due to the increase in the preference for solid fuels and

the growing demand for cooking energy, driven by the high population growth rate. One sees,

therefore, the need for greater intervention in the developing countries, where there are

already high levels of pollution and a precarious situation as regards the health services.

The substitution of cooking fuels along the energy ladder may reduce indoor air

pollution. However, the fuels are progressively more expensive as one goes up the ladder,

which prevents penetration of the clean fuels and more efficient technologies. Knowledge of

the factors which determine the energy transition is important in the formation of policies for

intervention in the supply of cooking energy. In addition, it is also important to study the

dynamics of energy transition in order to project demand for various kinds of fuels. In the

environmental assessment, the energy transition model may also be used in the projection of

quantities of emissions of gases and other polluting substances, and their consequences.

In order to reduce the demand for cooking energy, and deforestation, efficient stove

and kiln programs were introduced, both on the consumption side and on that of production of

charcoal and firewood. More recently, in addition to improved efficiency in the production

and consumption of cooking fuels, the importance of efficient stoves has arisen as a measure

to reduce indoor air pollution. The largest number of efficient stoves was disseminated in the

countries which had significant participation on the part of the private sector in the

manufacture and marketing of the stoves. Financing by the governments, however, was

necessary in activities like training, promotion and quality monitoring.

On the other hand, there was promotion of LPG and kerosene as replacements for

firewood and charcoal. Subsidised promotion for LPG and kerosene was practised as the

measure to keep prices more affordable to the users. The application of subsidies was the

biggest cause of price distortion for the other fuels derived from petroleum. However, in

addition to the burden on public finance and to price distortion, the subsidy increased LPG

consumption and diversified the supply of cooking energy in the residential sector. Such

subsidy programs are expensive, however, and benefit the affluent users more than the poor,

who lack conditions for acquiring LPG and kerosene, even at subsidised prices. As such, the

majority of the subsidy programs lack major impact on the improvement in quality of life of

the poor in the rural areas. The diversion of the use of subsidised LPG and kerosene occurs

with great frequency and makes the subsidy programs even more expensive.

54

Chapter 3

Access to and use of cooking energy in Tanzania.

This Chapter presents the current situation regarding supply and demand for cooking

fuels in Tanzania, as well as the socio-economic situation, access to and cost of energy,

emission of air pollutants and initiatives for improving the supply and consumption of

cooking energy. In order to reflect the differences between levels of service and quality of

cooking energy, comparisons are made between Tanzania and other countries.

3.1 Socio-economic characteristics

Tanzania is situated

in Africa, between the 1st

and 12th latitudes south of

the equator, and longitudes

29 and 39 east, next to the

Indian Ocean. Tanzania

possesses a surface area of

945,090 km2, the greater

part being formed of high

plains, at altitudes between

1,000 and 1,500 m.

Tanzania is surrounded by

eight countries, including

Kenya and Uganda

(north), Rwanda, Burundi

and the Democratic

Republic of the Congo

Figure 18: Map of Tanzania

Source: www.maps.com

55

(west) and Zambia, Malawi and Mozambique (south). To the east, Tanzania forms a boundary

with the Indian Ocean. The two largest lakes in Africa, Tanganyika and Victoria, are located

on the country’s northern and western borders. In the greater part the climate is tropical and

varies according to geographic characteristics and the distance from the Indian Ocean, from

arid to semi-arid and mountainous to forest and savannah. In the mountainous regions, the

temperature varies between 10° C and 20° C, and in the rest of the country the temperature

does not fall below 20° C. On average the country receives variable rain of from 500 to 2500

mm (URT, 2004).

The greatest concentration of the population is to be found in the largest cities like Dar

es Salaam, Mwanza and Arusha. According to the 2002 demographic census, the population

of the country has approximately 35 million inhabitants, distributed over twenty-five regions

(URT, 2004). The average population density in the country in 2002 was 38 inhabitants/km2.

The city of Dar es Salaam is the commercial capital of the country, and has a population

density of 1,793 inhabitants/km2, followed by Mwanza (150 inhabitants/km2) and Kilimanjaro

(104 inhabitants/km2). The region with the lowest density is Lindi, which has around 12

inhabitants/km2. Between 1988 and 1998 the annual urbanisation rate in Dar es Salaam was

around 6%; the country’s annual rate of population growth is 2.9% (World Bank, 2002). The

current population of the city is approximately 2.5 million inhabitants, with a number of

residents per family of around five (Malimbwi, 2001).

Tanzania’s GDP in the year 2002 was 9.4 billion USD, with a growth rate of around

6.3%. In the year 2002 the level of Gross National Income (GNI) per capita was 280 USD.

Per capita GDP has been improving from 1995 to 1998, accompanying the growth in GDP, as

presented in Figure 18. The monthly income of the majority of the population in the city of

Dar es Salaam varies between 20,000 TSH (20 USD) and 200,000 TSH (200 USD), according

to Malimbwi (2001). The Tanzania Department of Statistics estimates the city’s monthly per

capita income at around 40 USD.

56

Figure 18: Trend in GDP/capita between 1988 and 2002 in Tanzania.

0

100

200

300

1988

1990

1992

1994

1996

1998

2000

2002

PIB

per

cap

ita

[US$

]

0

5

10

15

PIB

[US$

bilh

ões]

PIB percapitaPIB

Source: URT (2004).

The analysis of expenditures per capita of the population shows that 20% of the

population (first quartile) spends less than 3,015 TSH (3.0 USD) per month. Another quintile,

at the other end (Q5), represents the group with the level of expenditures of above 19.20

USD. Expenditure levels per capita in Dar es Salaam are higher than the national levels.

Table 18: Expenditures of available income per capita, by quartile36 over a 28-day period in Tanzania. Quartile Q1 Q2 Q3 Q4 Q5 Tanzania [TSH] 3,015 5,003 6,819 9,649 19,359 Dar es Salaam [TSH] 3,279 5,116 7,108 9,796 23,717

Source: NBS (2003).

Tanzania has a lower HDI relative to various other developing countries, and per capita

consumption of commercial energy37 is less than 500 kgpe, as presented in Figure 19. As like

in other underdeveloped countries, the low HDI corresponds to the low consumption of

commercial fuels, in comparison with the developed countries. Petroleum and electrical

power represent, respectively, only 7% and 2% of the supply of energy, while coal, wind and

solar energy, together represent around 1% of consumption. Bio-mass accounts for 90% of

primary energy supply (Kaale, 2001) and the WEC (1999) estimates that the wooded area in

Tanzania is 388 thousand km2 and the potential for bio-mass energy production is 34.5

million tonnes (510 thousand TJ) per year.

36 The quartiles are values of the variable [valores da variável -- ??] which divide the distribution of the frequency

into five equal parts [therefore quintiles, no?]. Q1, the first quartile, is the value of the variable such that the number of observations less than Q1 is 20% and the number of observations above is 80%."

37 Commercial energy refers to a energy source of high quality and combustion efficiency, normally sold on open markets. It includes, for example, electrical power and the petroleum derivatives, and excludes the traditional sources such as unprocessed bio-fuels.

57

Figure 19: Comparison of the Human Development Index (HDI) and energy consumption per capita of Tanzania and other countries in 2002

Jamaica

NigeriaTanzania

)Congo (Zaire

South Africa

France NorwayUnited States

India

ChinaBrazil Chile

0

0.2

0.4

0.6

0.8

1

1.2

0 1 2 3 4 5 6 7 8 9Per capita consumption of commercial energy [kgep]

HD

I

Source: World Bank (2004), UN (2004).

The residential sector is the largest consumer of energy: in 1990 it was responsible for

around 80% of consumption, around 561 thousand TJ. Trends in consumption of useful

energy in the residential sector show a linear relationship with population increase, there

being no direct relationship with variations in GDP. Per capita consumption during the period

from 1988 to 1996 is 1.5 GJ per annum, as presented in Figure 20.

Figure 20: Trend in consumption of useful energy in the residential sector in Tanzania between 1988 and 1996

0

10

20

30

40

50

1988 1989 1990 1991 1992 1993 1994 1995 1996

Con

sum

ptio

n [P

J],

Pop

ulat

ion

[mill

ion

in

habi

tant

s]

2

3

4

5

6

7

GD

P [b

illio

n U

SD] Total consumption

of useful energy]PJ[Population]millions[

GDP [billion]USD

Note:

• The consumption of woodfuel, charcoal and LPG was considered. The literature reviewed does not present

information on the consumption of kerosene solely for cooking, since generally the information on the use

of kerosene does not make the distinction between kerosene use for cooking and for lighting.

• The efficiency of wood stoves was considered to be 15% and that of charcoal stoves, 20%.

Source: FAO (1995), Bank of Tanzania (2004).

58

3.2 Supply and consumption of the main cooking fuels in Dar es Salaam.

This part presents the current situation of the use and market in various sources of

cooking energy (charcoal, kerosene and LPG) in Tanzania. Mwandosya and Meena (1999)

estimate that annual consumption of firewood and charcoal in the country is around 32

million cubic metres, of which one third derives from the harvesting of wood for production

of firewood and charcoal, while the remaining two-thirds come from clearing for agricultural

activities. Consumption of bio-mass per capita varies between 0.5 m3 and 2.10 m3/year, with

the average being 1.5 m3/year.

The majority of the homes in Dar es Salaam uses more than one kind of cooking fuel

(Malimbwi, 2001), as presented in Table 19. Charcoal is the most preferred fuel and is used

more frequently than the others. The use of other second- and third-choice fuels only occurs

as an alternative, in the cases in which it is more convenient to use other fuels or there is a

lack of supply of the more preferred fuel. The preference for charcoal increased during the

ten-year period between 1991/92 and 2000/01, from 51% to 69% respectively (Malimbwi,

2001). Hosier and Kipondya (1993) and Ishengoma and Ngaga (2001), in Malimbwi (2001),

estimate this percentage as around 73% and 86% respectively. According to Malimbwi

(2001), high electrical power costs and the worsening of the financial conditions of the

population are amongst the most prominent causes of the decline in preference for kerosene

and electrical power.

Table 19: Preferences in the use of cooking fuels in Dar es Salaam in 2001. Choice preference [percentage of homes] Kind of fuel First Second Third

Charcoal 69 25 3 Kerosene 25 53 5 Electrical power 4 6 17 LPG 1 2 0 Others 1 14 75

Source: Malimbwi (2001).

Neubauer (2002) presents the trends in the percentage of use of various cooking energy

sources in the city, between 1990 and 2000. According to Table 20, the percentage of use of

traditional charcoal stoves declined over this period, from 64.10% to 43.70%, at a constant

rate of approximately 4%. On the other hand, the percentage of use of efficient charcoal

stoves increased from 13.13% in 1990 to 26.25%, at an annual rate of 7%. The percentage of

59

use of electric stoves and kerosene stoves also increased, at a rate of 3% and 2% respectively.

When extrapolated, the percentages of penetration in 2004 are 35.7%, 35.7%, 22.8% and

3.9%, for traditional stoves, efficient stoves, kerosene and electrical power, respectively.

Table 20: Percentage of use of different kinds of stoves in Dar es Salaam. Percentage of use (%) Fuel/stove

1990 2000 Traditional charcoal stoves 64.10 43.70 Efficient charcoal stoves 13.13 26.25 Kerosene 18.75 21.88 Electrical power 3.0 4.0 Gas and others 1.0 4.0

Source: Neubauer (2002).

According to Mwandosya and Meena (1999), in the year 1990 only 4.9% of homes in

the country used efficient charcoal stoves. Since that time, the rate of penetration of the stoves

is estimated at around 3% per year and foreseen to reach saturation (90%) in the year 2020.

Malimbwi (2001) calculates the rate of penetration of efficient stoves in Tanzania and in Dar

es Salaam at around 26% and 41% respectively, in 1998 and 2001.

3.2.1 Charcoal Charcoal is the largest source of cooking energy in the urban areas in Tanzania. The

fuel is considered locally to be a modern source, unlike firewood, agricultural residues and

dung. Charcoal may be acquired in small quantities, does not go bad even during long periods

in storage, and burns easily even in simple stoves. It is a domestic source of energy the

production and use of which do not require high technology. With these characteristics,

charcoal becomes one of the cheapest options in the country for cooking. The production,

distribution and sale of charcoal constitute one of the largest industries in the informal sector,

offering employment and income for the majority of people in the rural and urban areas, since

there are no better survival alternatives (Malimbwi, 2001).

Production of charcoal

Nearly all charcoal used in Tanzania is produced in traditional earth mound kilns,

similar to the Kenyan kilns presented in Pennise et al. (2004) in Section 2.3.2. These kilns, as

presented in Table 8, have a charcoal production yield of between 21% and 34%, according to

tests carried out in 2004. Mwandosya and Meena (1999) show that the kilns used in Tanzania

have a yield of around 1 Kg of charcoal for every 6 Kg of wood used, consistent with the

amount presented by Pennise et al. (2004). Consumption of charcoal for cooking is around

60

43.1 million sacks (average weight of 28 kg) per year, equivalent to 1,200 million tonnes

(Malimbwi, 2001). Due to deforestation in the outlying areas of the city, the distance from the

points of charcoal production to the city increased from 50 km in the 1970s, to 200 km in the

nineties.

According to Malimbwi (2001), the intensity of harvesting of wood in the areas of

charcoal production is greater in the unpreserved areas (9.81 ± 2.3 m3/ha/year) than in the

managed forests in reserved areas (3.55 ± 0.8 m3/ha/year). The average rate of harvesting of

wood is 6.4 m3/ha/year. In these areas, the greater part of the wood harvested is used in the

production of charcoal (75%), logging (12%), agricultural activities (7%) and others (6%).

Malimbwi (2001) shows that regulation and management do not exist in the wooded areas.

Reforestation only occurs through the natural reproduction of brushwood and shoots, and

there are few reforestation programs in the charcoal production areas. The mean annual

increment (MAI) was 2.3m3/ha in the managed forests and 1-2m3/ha in the unmanaged areas.

The greater part of the charcoal consumed in Dar es Salaam is produced in the unpreserved

areas (Malimbwi, 2001). Comparing the rates of consumption and reforestation for charcoal

production, one concludes that consumption is three times greater than reforestation. Only

one third of all of the woods consumed annually is recovered through reforestation, and thus

the use of wood for charcoal production is not sustainable. One concludes as well that the

CO2 produced in the production of charcoal is not completely reabsorbed by reforestation,

and instead accumulates in the atmosphere, increasing the inventory of greenhouse gases.

Per capita charcoal consumption

In the year 1998 the consumption of charcoal in the city of Dar es Salaam was around

360 thousand tonnes, accounting for approximately 50% of total consumption in the country

(Mwandosya and Meena, 1999). On average, per capita consumption is around 168 kg/year,

or 5.25 GJ/year of energy. Taking into account an average combustion efficiency of 20% and

the loss of 20% due to handling and transport, useful energy per capita is 1.05 GJ,

representing an average useful energy value which is consistent with the values found in the

literature (Section 2.1.1.

Malimbwi (2001), looking at the residential sector only, estimates the consumption of

charcoal for cooking at around 345 thousand t/year. Hosea and Kipondya (1993), cited by

Malimbwi (2001), calculate consumption per family at around 77 kg/month, and Ishengoma

61

and Ngaga (2001) estimate it at around 87 kg/month, suggesting an increase in consumption

of charcoal at household level. Daily consumption for a family of five persons is around 2.8

Kg, and daily consumption in the city is in the range of 800 to 1400 tonnes (Malimbwi,

2001). With the average number of residents per residence being equivalent to five, per capita

consumption is approximately 0.6 Kg/day. Considering the average efficiency of the charcoal

stoves at 20%, and the lower heating value (LHV) of charcoal being equal to 30.8 MJ/Kg

(IPCC, 1996), consumption per capita of useful energy is approximately 1.35 GJ/year.

Charcoal industry in Tanzania

The marketing of charcoal in Dar es Salaam involves actors in a reasonably complex,

chain such that it becomes difficult to identify all of them and all of their activities. Figure 21

presents the simplified marketing structure for charcoal in this city.

Figure 21: Charcoal marketing chain in Tanzania.

Source: Malimbwi (2001).

The producers of charcoal and woods are located in the rural areas and are represented

by agencies in the city. The wholesale agencies are traders who also have or rent means of

transportation to take the product to the city. There are also independent transporters who are

Wood sources (public forests (illegal), private plantations, rural

landholdings).

Owners /Producers

Transporters (by truck, bicycle,

etc).

Wholesalers (charcoal storehouses)

Consumers (homes,

commerce, institutions).

Resellers (stalls in markets, kiosks).

Taxes (Trucks, bicycles).

62

contracted just for the transport. Another group is that of transporters who use bicycles, and

the majority are residents in the outlying areas of the cities, close to the points of charcoal

production. The transporters can sell charcoal to wholesalers, resellers or to end consumers

themselves, in the case of the transporters who use bicycles.

For charcoal production, as well as for other uses of forest resources from the wooded

areas in Tanzania, there should be permission and licensing from the Directorate of Forests

and Bee-Keeping (DFA). The average rate of taxes for every sack of charcoal (weighing 28

Kg) is 400 TSH (0.40 USD), according to Malimbwi (2001). Nevertheless, the production and

marketing of charcoal are less controlled and inspected. The producers normally don’t pay to

use the wood harvested for charcoal production. The taxes for harvesting of the wood

(stumpage fee), reforestation, and the costs of the harmful effects caused by the loss of

vegetation, are not included in the end price of the charcoal. The end price of the charcoal

includes only the costs of manpower, transport and handling, plus margins charged by

resellers (Malimbwi, 2001).

It is estimated that on average six thousand sacks enter the city per day, but this is a

conservative estimate, since there is a large volume of charcoal transported during the night

for the purposes of tax avoidance. The percentage of non-inspected charcoal reaches as much

as 41% of the total volume. In 2000, the collection of taxes from the importation of charcoal

to the city was 4.5 million TSH (4.2 thousand USD) per day, representing the potential to

collect 20 thousand USD/month or 240 thousand USD/year. With 3,500 TSH (3.2 USD)

being the retail price of a sack of charcoal, considering only the number of sacks inspected,

charcoal marketing in Dar es Salaam moves some 7.5 million USD/year.

3.2.2 Kerosene and LPG

Kerosene is generally used for lighting of the homes that lack electrical power.

According to CEEST (1997), in 1990 90% of the population of Tanzania used kerosene for

lighting, using wick lanterns. In the urban areas where the greatest access to electrical power

exists, kerosene is used for cooking in wick or pressurised stoves. The most common

kerosene stoves have an efficiency of around 35% (TaTEDO, 2002) and emit a large quantity

of smoke during their use and also when they are put out. In 1990 the country consumed 79

thousand tonnes of kerosene (CEEST, 1997); however, the source did not distinguish the

proportions of consumption for cooking and for lighting. If all of the kerosene were used for

63

cooking, it would supply sufficient energy for 1.4 million38 people. Kerosene may be acquired

in small quantities, which makes it a more affordable fuel.

CEEST (1997) calculates that the consumption of LPG was 5.0 thousand tonnes in 1990

and TaTEDO (2002) highlights that consumption fell to 3.6 thousand tonnes or 0.1 Kg per

capita in 2001. Gas consumption in the rural areas is practically zero, and in general it is more

common in some urban areas, amongst high-income consumers. During the fiscal year

2003/04, the government of Tanzania reduced customs duties on LPG from 0.26 USD/Kg to

0.13 USD/Kg, and as a result one saw a 50% increase in consumption. Current consumption

of the gas was not presented, although it may be estimated at around five thousand tonnes,

based on the TaTEDO report (2002). All of the LPG consumed in the country is imported.

The distribution of LPG for residential use in Tanzania, which accounts for 63% of total

annual consumption, is undertaken in 15-Kg bottles. Recently, in order to make possible the

acquisition of gas in smaller quantities, smaller 6-Kg bottles were introduced, together with a

gas nozzle and burner support frame (TaTEDO, 2002). In addition to being sold at relatively

low prices, the inclusion of the gas nozzle and frame avoids the need to buy a gas stove. On

the first purchase, the price of the gas and the set consisting of a 6-Kg bottle, a gas nozzle and

frame, varies between 50 and 70 USD. In 2001 the prices for LPG, of which 35-40%

consisted of taxes, were between 1,312 USD/t in Dar es Salaam and 1,512 USD/t in other

cities in the interior. The price of the imported LPG, still at the port and before taxes, was 470

USD/t.

The consumption of kerosene and LPG followed the same path between 1989 and 2002.

There was a decrease in the consumption of the two fuels from 1989 to 1996, when

consumption of each reached its maximum level. Between 1996 and 2000, consumption of

kerosene and LPG fell drastically from 203 and 9 thousand tonnes, to 87 and 3 thousand

tonnes respectively (AFREPREN, 2004), due to the increased prices of petroleum derivatives

in the Persian Gulf (Section 2.2.2, Figure 3). The Persian Gulf is the largest supplier of the

petroleum derivative fuels used in Tanzania. After 2000 LPG and kerosene prices began to

fall, and consumption of the two fuels has been growing at a rate of approximately 30% per

year, as presented in Figure 22.

38 One took into account per capita demand of 1 GJ/year, kerosene stove efficiency of around 40% and a lower

heating value of the kerosene of 44.45 GJ/t.

64

Figure 22: Trend in the consumption of kerosene and LPG in Tanzania between 1989 and 2002 [thousand tonnes].

0

24

68

1019

89

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

LPG

0

50100

150200

250

Ker

osen

e

LPG

Kerosene

Source: AFREPREN (2004).

3.2.3 Non-conventional fuels: biogas, mineral coal and natural gas

Biogas:

Tanzania has approximately fifteen million cattle, which could produce around forty

million tonnes of manure per year (Kassenga, 1997). There are also large quantities of organic

residues which could be decomposed to produce biogas. The technology of biodigestion was

introduced in the fifties, but its dissemination on a large scale for domestic and institutional

use only began in 1975. In 1994, the Centre for Agricultural Mechanisation and Rural

Technologies of Tanzania (CAMARTEC) had built 1000 biodigestor units (AFREPREN,

2002), Sheya and Mushi (1999). The most popular model of biodigestor, dubbed the

“CAMARTEC”, is adapted from the Chinese models, with a fixed dome and using dung as its

input material. This model of biodigestor consumes large quantities of water, at times in even

greater volumes than the daily consumption of a rural home. Its average cost is around 1,000

USD. Another model of low cost biodigestor was developed, with the experience of Vietnam

and India being used (Hifab/TaTEDO, 1998). This model cost 80 USD, as it is built with

simple technology and cheaper materials. Water consumption was significantly reduced and it

was able to produce biogas with less dung consumption.

The biodigestor technology was developed for application in the rural areas. However,

logically the installation, operation and maintenance of the biodigestors are difficult. The high

cost and large consumption of water and dung were amongst the greatest impediments to the

dissemination and adoption of the biodigestors. As such, the potential for biogas as a cooking

fuel within the Tanzanian energy matrix is marginal. The current situation of dissemination of

65

this technology isn’t known, despite the presence of some dissemination programs in the

process of being executed (Kassenga, 1997).

Mineral coal

The coal reserve is estimated at around 1,200 million tonnes, of which 200 million are

bituminous, with a potential for use in cooking (URT, 2003). The coal production fields are

concentrated in the southwest area of the country. Current production is 100 thousand t/year,

with the greater part of this coal being used in the production of electrical power, and with a

capacity of only 6 MW, producing 20 GWh in 2001. The bituminous coal available in

Tanzania is of medium quality, with 24% volatile contents, 10% ash and 0.6% sulphur. Its

calorific value is around 29.30 MJ/tonne and the density is around 850 kg/m3, which is

equivalent to three to four times greater than that of charcoal. The coal market in the Tanzania

residential sector is practically non-existent (URT, 2003).

There are logistical limitations on transport, marketing and use of mineral coal. The

charcoal production fields are located far from the cities where the residential consumers are

found (URT, 2003b). Despite the presence of a rail line and roads which link the cities and the

production fields, transport costs are very high, and thus coal prices to the end consumers

become more expensive than the prices for charcoal, kerosene and electrical power. Given

that coal burns slowly in domestic stoves and produces more heat which causes hotspots, its

use for cooking is highly limited.

Natural gas

Tanzania possesses reserves of natural gas of around 0.98 trillion cubic feet, or 27.73

million m3. The gas was discovered in 1974 in a deposit on an island in Songosongo, in the

south-east of Tanzania. The deposit is located off-shore, at a distance of 25 km from the coast

of the Indian Ocean. However, the gas is used for generation of electrical power (115 MW)

and other industrial consumption in Dar es Salaam. There is a twelve-inch diameter gas

pipeline which takes the gas up to the city, at a distance of 225 km.

3.3 Comparison of energy costs

The average prices for fuels vary, depending on transport costs, operating costs and

taxes. Hosier and Kipondya (1993), cited by Foster (2000), showed a large variation between

66

prices charged39 and real prices40 in the use of five of the most common cooking fuels in Dar

es Salaam in 1990. According to the authors, electrical power is the cheapest of all. The

government of Tanzania promotes the use of electrical power, through subsidies on the end

price to the consumer. In 1990, 94% of the price of electrical power for residential consumers

was subsidised, in order to improve its accessibility. The cost to use electrical power in a

home with monthly demand of 320 MJ (89 kWh), was 657.99 TSH (1.5 USD)41 in terms of

price charged, but the real price would be 3,779.93 TSH (8.6 USD).

Hosier and Kipondya (2003), in Foster (2002), show that there are subsidies practised

on these fuels, and on the prices for charcoal and woodfuel as well. Adding up the real costs

of the cooking fuels and their monthly costs, one observes that charcoal is the cheapest option

on the list. Table 21 presents the costs to use the five cooking fuels in a residence with

monthly demand of 320 MJ.

Table 21: Costs42 of using various cooking fuels in Dar es Salaam, in 1990

Cost of useful energy

[USD/MJ]

Total cost for consumption of 320

MJ [USD] Fuel

Charged Real

Monthly cost of the stove (amortised)

[USD] Charged Real Firewood 0.009 0.012 n/a 2,869 3,841 Charcoal (traditional) 0.008 0.013 0.051 2,665 4,162 Charcoal (efficient) 0.005 0.009 0.285 2,027 3,026 Kerosene 0.012 0.021 0.076 3,894 6,731 LPG 0.007 0.010 0.475 2,789 3,747 Electrical power 0.001 0.024 1.044 1,499 8,610

Source: Hosier and Kipondya (1993), in Foster (2000).

Approximately ten years following this observation on the part of Hosier and Kipondya

(1993), TaTEDO (2002) shows that the use of charcoal in efficient stoves is still the cheapest

alternative for cooking. While the cost of electrical power per MJ has been maintained over

the ten years, the cost of firewood tripled, that of charcoal and kerosene doubled, and that of

LPG quintupled. LPG underwent the biggest price increase, contrary to kerosene and

electrical power, which may mean the continued application of subsidies on the prices of the

39 The price of a fuel in the market 40 The real price corrects the distortions in the price due to subsidies and additional costs like taxes, royalties and

parity for the imported fuels. 41 Current value in 1993 42 Original prices in TSH, converted into current 1993 USD, equivalent to 439 TSH

67

two. The use of LPG costs two to three times more than that of charcoal in an efficient stove,

as presented in Table 22.

Table 22: Costs of cooking energy per quantity of energy produced, in Dar es Salaam in April 2002

Fuel Uni

t

Pri

ce to

the

cons

umer

. [U

SD/u

nit]

Lower heating value

Cal

orif

ic v

alue

M

J/un

it

Eff

icie

ncy

of th

e st

ove

Use

ful e

nerg

y (M

J)

Cos

t of u

sefu

l en

ergy

[U

SD/M

J]

LPG kg 1.30 47.31 GJ/tonne 47.31 55% 26,021 0.050

Kerosene (kerosene stove with wick burner) litre 0.43 37.5 GJ/m3 37.5 35% 13,125 0.033

Kerosene (pressurised stove) litre 0.43 37.5 GJ/m3 37.5 50% 18,750 0.023

Residential electricity kWh 0.10 3.6 MJ/kWh 3.6 80% 2,880 0.035 Charcoal (traditional stoves) kg 0.12 20.1 GJ/tonne 20.1 20% 4,020 0.031

Charcoal (efficient stoves) kg 0.12 20.1 GJ/tonne 20.1 35% 7,035 0.018

Woodfuel from native sources kg 0.08 14.8 GJ/tonne 14.8 17% 2,516 0.031

TaTEDO (2002).

The current price trend for charcoal between 1995 and 2000 shows an increase of 1,000

TSH/sack to 3,800 TSH/sack (Malimbwi, 2001). When the prices are converted into

American dollars (USD), the trend shows a fall in the price. In economic terms, this trend

suggests that supply of charcoal is greater than its demand, and that the price increase in local

currency is attributed solely to inflation. The average price of charcoal during this time period

is 4 USD/sack of 28 Kg, or 0.14 USD/Kg, as presented in Figure 23.

Figure 23: Trend in the price of charcoal in Dar es Salaam, between 1995 and 2000

2

3

4

5

6

1995 1996 1997 1998 1999 2000

Pri

ce [U

SD/s

ack]

0

1000

2000

3000

4000

Pri

ce [T

SH/s

ack]

]USD[

]TSH[

Source: Malimbwi (2001)

68

3.4 Cooking energy, air pollution and effects on health

As was discussed in Section 2.4 of this work, the use of cooking energy is one of the

biggest causes of GG emissions. As they constitute simple equipment, small-scale and

frequently manufactured without great precision or quality control, domestic stoves produce

high quantities of emissions (CEEST, 1997). In a country like Tanzania, where 80% of the

energy is consumed in the residential sector, the consumption of cooking energy has a great

impact on the quantity of the country’s GG emissions.

3.4.1 GG emissions in the consumption of cooking energy

The estimates of GG emissions from Tanzania’s residential sector are presented by

CEEST (1997) in Table 23.

Table 23: Estimates of GG emissions from the residential and commercial sector in Tanzania in the year 1990 [Gg]

Fuel Consumption (PJ)

CO2 CH4 NOx N2O CO

Charcoal 23.08 2167,16 1.10 2.35 0.07 82.75 Firewood 513.65 39,856.66 173.92 33.57 1.20 1014.53 Kerosene and LPG 3.73 264.74 0.02 0.19 n/a 0.05 Source: CEEST (1997).

3.4.2 GHG emissions in charcoal production

The production of charcoal (C) produces, in addition to coal, condensed liquids (CL),

ash and the gases CO2, CO, CH4, non-methane organic compounds and total suspended

particles (TSP), as presented in Equation xi.

SPSNMOCsCHCOCOAshCLBranchesCVWood ++++++++= 42 Equation xi

CEEST (2001) estimates that the production of charcoal in Tanzania in 1990 was

around 741 thousand tonnes, consuming 7.7 million tonnes of wood. The estimates for GG

emissions in Tanzania in 1990 from charcoal production, were as presented in Table 24,

which also includes the estimates of emissions in Brazil and Kenya in 1996, for comparison.

Table 24: Greenhouse gas emissions from charcoal production in Tanzania (1990), in Mt.

Kiln Prod’n CO2 CO CH4 NMOCs NOx N2O Tanzania (1990) 0.74 10.3 0.26 0.240 - 0.008 0.0003

Kenya (1996) 2.20 3.1 0.49 0.097 0.20 0.00014 0.00032 Brazil (1996) 6.40 8.6 2.00 0.310 0.47 0.00016 0.00028

Source: CEEST (2001), Pennise et al. (2004).

69

3.4.3 Air pollution and health impacts

No information was found on the impacts of charcoal use on health in Tanzania.

Nevertheless, ARIs are amongst the diseases which most frequently lead patients less than

five years of age to the out-patient clinics, as presented in Table 25. In Dar es Salaam, ARIs

occupy second place in all doctor’s appointments at 13%, losing out only to malaria, which

leads with 50% (Mtasiwa et al, 2003).

Table 25: Number of out-patients with diseases caused by acute respiratory infections in Tanzania amongst children under five years of age.

Infections/diseases 1998 1999 2000 Acute respiratory infections (ARIs) 2,306 8,530 6,401 Other diseases of the airways 658 2,301 1,555 Total 80,862 214,023 175,120 ARI as percentage of all diseases 3% 4% 4%

Source: TSED (2004).

The contribution of ARIs is relatively minor to the number of deaths in Dar es Salaam

amongst children under five years of age, contributing between 1% and 2% of the deaths, as

presented in Table 26.

Table 26: Number of deaths caused by ARIs in Tanzania amongst children under five. Infection/disease 1998 1999 2000 Acute respiratory infections (ARIs) 49 140 59 Other diseases of the airways 28 46 27 Total 3,306 7,676 6,595 ARI as percentage of all deaths 1.5% 1.8% 1%

Source: TSED (2004).

3.5 Efficient stove programs in Tanzania

The Tanzanian efficient stove, jiko bora, was developed by adopting and modifying

the ceramic stove from Kenya (KCJ). The jiko bora is also made of ceramic and metal parts

and may reach thermal efficiency of 35%. Recently, another model of efficient stove was

introduced into the market, with a thicker ceramic insulator, making possible thermal

efficiency of up to 44% (Pesambili, 2003). The efficient charcoal stoves are mobile, with no

chimney, and have a grate and damper to control the supply of combustion air. The diameter

of the fireplace is 250 mm and the height of the stove is 220 mm. In order to facilitate the

movement of the air within the stove and the removal of ashes, 15- to 22-mm holes are made

in the grate. There are more than ten models of efficient stove, with prices varying between

3.00 USD and 20.00 USD, some of the most popular being presented in Figure 24.

70

Figure 24: Charcoal stoves in Tanzania.

Traditional stove in a cylindrical shape,

with all parts in metal

Efficient stove in an hour-glass shape43

Efficient stove in a cylindrical shape;

fusion of the traditional and KCJ stoves.

Efficient stove in a conical shape with two chambers of ceramic

insulator

There is no consistent and more up-to-date information on the quantity of stoves

disseminated in Tanzania. Karekezi (2002) estimates around 54 thousand efficient charcoal

stoves since 1988. Mwandosya and Meena (1999) estimate that in 1990, the number of

efficient stoves was around 79 thousand units, used in only 4.9% of urban homes.

The development of efficient stoves and the popularising of clean technologies are

indirectly subsidised, through funding for the manufacture of efficient stoves and the

production of charcoal. The first initiative to widen the use of the efficient charcoal stoves at

national level was launched in 1988, in a project financed by the World Bank (around

268,000 USD) and carried out in the city of Dar es Salaam by the Ministry of Energy and

Mines (MEM) of Tanzania, between 1988 and 1990 (World Bank, 2003). The project adapted

the Kenyan ceramic stove model. In 1992, TaTEDO took over the activities of dissemination

of the efficient stoves from MEM, in the training of artisans in the manufacture of stoves, the

administration of loans to producer groups, and the offering of technical support.

Between 1997 and 1998, TaTEDO carried out another project to evaluate the

dissemination of the efficient stoves in the urban areas of the country. This project had its

origin in the fact that production of the efficient stoves in the city did not grow satisfactorily

at the level foreseen earlier: demand in 1995 was only 4,000 units, instead of 12,000 units per

month. The total of 25,724 USD was invested in this project by the UNDP-GEF.

43 The body is made up of two conical vessels (steel plate) which communicate at the vertices by an orifice with a

smaller diameter than at its extremities.

71

From 1999 to 2003, TaTEDO carried out another project on development of renewable

energy sources and conservation of the environment. The project, which was worth around

200,000 USD and was funded by HIVOS, NORAD and the European Union, had as its

objective to improve the quality of life of the population, through the use of clean and

sustainable energy for the majority of the population. The project was carried out in Dar es

Salaam and in four other regions in the interior. At the same time, UNEP financed a 125,000

USD project, through the AREED program44, aiming to support the development of

undertakings in the area of renewable energy and energy efficiency (AREED). From the

information in the four paragraphs above, the amount of subsidy is estimated at around 390

million USD.

3.6 Summary of the chapter Tanzania has a relatively very low per capita income, which directly impedes adoption

of the use of commercial fuels like LPG and kerosene and electrical power. The country’s

energy sector is highly dominated by bio-mass, this being the typical characteristic of

underdeveloped countries, with the residential sector being the largest consumer. The

production of charcoal is also practised in an inefficient way, and is one of the biggest causes

of deforestation. All of the charcoal marketing activities offer a means of economic survival

for thousands of people in the informal sector. The price policies and inspection mechanisms

do not ensure that the price of the charcoal reflects its economic cost to society. There are

insufficient efforts in the collection of stumpage fees and taxes on the marketing of the

charcoal in the city; in this way, the real costs of deforestation are not included in the end

price to the consumer.

The use of charcoal in efficient stoves presents a cheaper option for cooking than the

use of LPG or kerosene in supplying cooking energy for Dar es Salaam. Kerosene

consumption is also widespread in Tanzania, since 84% of the population uses it for lighting.

Its consumption, however, is highly driven by the poor access to electricity in the rural areas.

In Dar es Salaam, 43% of homes already use kerosene, in combination with other cooking

44 AREED is an program for the development of rural energy companies in Africa, funded by the United Nations Foundation; it had its origin in a partnership between the United Nations Environment Program (UNEP) and E+CO, an energy investment institution. AREED seeks to develop new sustainable energy companies which use clean, efficient and/or sustainable technologies to meet the energy needs of populations currently under-served by conventional energy means. However, the objective of AREED is to reduce the negative consequences on health and the environment which derive from the use of the energy patterns in effect, at the same time stimulating local growth. More information at the following site: http://www.areed.org/.

72

fuels. The use of biogas, more appropriate in the rural areas, is limited due to the high costs of

installation, operation and maintenance.

As in other countries which are major consumers of bio-mass, there have already been

programs for dissemination of efficient stoves in Tanzania. However, their effectiveness and

impacts are not known, as consistent information do not exist on the number of stoves

disseminated and the benefits achieved. Fifteen years after the first efficient stove program

began in Tanzania, in 2003 a new approach was launched with a commercial vision, joining

up with the initiatives to disseminate efficient stoves in the country.

73

Chapter 4:

Quantitative analysis of the impacts of substitution of

traditional fuels in Dar es Salaam in Tanzania

As was discussed in the foregoing chapters, there are various interventions aimed at

improving the supply and quality of cooking energy. These interventions, needed in order to

reduce the demand for cooking energy, consumption of primary energy sources, air pollution

and deforestation, include the replacement of traditional stoves and fuels by efficient stoves

and modern fuels. The implementation of these interventions, however, has impacts which

extend not only to the demand for energy products and the reduction of pollution, but also the

reduction of greenhouse gas emissions and cost savings in the introduction and use of new

technologies and new fuels. In this chapter one seeks to identify the possible interventions and

the major impacts in carrying them out in the city of Dar es Salaam in Tanzania, between

2005 and 2025.

4.1 Methodology

The analysis is undertaken for the city of Dar es Salaam, located on the eastern side of

the country and occupying an approximate area of 1,392 km2, which serves as the commercial

and industrial capital of Tanzania. It is the country’s largest city, with a population of 2.5

million inhabitants, making up 7% of the population of the country. The city consumes

approximately half of the charcoal (360 thousand t/year) produced in the country, and its

population has relatively better buying power than the average for the country. It is

considered to be the case that success in the adoption of new technologies and modern fuels

in Dar es Salaam may be propagated rapidly to other cities in the country. In addition, there is

more information documented on the consumption of energy and other socio-economic

characteristics in Dar es Salaam, than on the rest of the country.

74

The first stage in the analysis is to identify the possible interventions to reduce the

demand for cooking energy and indoor air pollution. The identification is based on the

information developed in Chapters 2, 3 and 4, given its relevance for the current situation in

the city of Dar es Salaam. Table 27 summarises the main options for reducing indoor air

pollution and the emission of greenhouse gases into the atmosphere. In the first column are

interventions for the reduction of indoor emissions, through improvement in ventilation and

use of a chimney. The advantages of improving ventilation and of using a chimney are

insufficiently quantified and documented. Thus, it makes difficult the evaluation of their

benefits as interventions to reduce pollution. The use of efficient stoves, the impacts of which

are amply documented, is analysed as an intervention to reduce the demand for cooking

energy, pollution and GG emission. In the second column, the maintenance of the stove

depends on the user, it is a necessary intervention for the best operation of any kind of stove.

The third column presents various fuels as possible replacements for charcoal. While

the installation of biodigestors and the manufacture of brickets for residential consumption

have not been successful in Tanzania, the use of coal and natural gas is unlikely in the short

term. The use of electrical power is also unlikely, due to the limitation in capacity for

production in the country. It is likely that the country’s electrical system does not bear up

under the increased load for cooking in the city. Current generation is 2036 GWh/year, and

meets the demand of only 10% of the population of Tanzania (URT, 2003). Taking into

account the efficiency of electric stoves of around 75%, 2036 GWh may offer cooking energy

for only 5.5 million people (approximately one million families). Kerosene is already on the

market and any initiative to promote its consumption through subsidies may face price

distortion and diversion of its consumption, as has happened in India. There are few

companies that import and sell LPG in Tanzania on their own initiative; however, the

penetration of LPG in the market is less than 1%. It being the cleanest fuel and advantageous

in reducing energy demand and pollution, in this work one seeks to confirm the benefits and

impacts of greater development of the LPG market.

The fourth column presents the interventions in supply of charcoal. The introduction of

efficient kilns in charcoal production will reduce the consumption of wood more quickly,

consequently reducing deforestation. The forest-farming programs require a long timeframe

(at least seven years) for the harvesting of wood. This means that they won’t have immediate

75

results in the reduction of deforestation, and accordingly, this justifies the introduction of

efficient kilns as the measure which in addition to reducing consumption of wood, also

reduces the emission of GGs. Prohibition on the use of charcoal, in the fifth column, did not

meet with success in Senegal, and probably will likewise not be successful in Tanzania. The

production and marketing of charcoal employ thousands of people. The implementation of

efficiency standards may be incorporated into efficient stove programs, as a regulatory

measure.

Table 27: Interventions to reduce the disadvantages of use of traditional fuels.

Kitchen and stoves Behaviour in their use

Switching fuel Supply-side management

Regulation

1. Improvement in ventilation

2. Use of chimney and hood

3. Kitchen built outside the home

4. Efficient stove 5. Efficient stove

with chimney

1. Maintenance of stoves

1. Brickets45 2. Kerosene 3. LPG 4. Biogas 5. Electrical

power 6. Mineral coal 7. Natural gas

1. Sustainable forest-farming

2. Improvement in the efficiency of charcoal production

1. Prohibiting the use of charcoal

2. Establishing efficiency standards for stoves and kilns and quality standards for charcoal.

The interventions with greatest advantages for energy demand and air pollution in the

atmosphere and indoors, are as follows: introduction of efficient stoves and kilns, and

introduction of LPG. These interventions will be analysed under two scenarios as against the

baseline scenario. The scenarios do not seek to predict demand, having as their objective only

to demonstrate the possibilities within the cooking energy matrix and their advantages or

disadvantages.

Using the constant value of consumption of useful cooking energy and the population

estimates, it was possible to project energy demand from the year 2005 to 2025. Consumption

of primary energy is calculated for each one of the scenarios, taking into account

technological aspects (efficiency and heating value of fuels) and variation in the participation

of each of the kinds of fuel in residential consumption. In this stage, concentrations are also

calculated of indoor and outdoor air pollutant emissions, using emissions factors

recommended by the Intergovernmental Panel on Climate Change (IPCC), from 1996. The

summary of this analysis is presented in Figure 25.

45 Bricketing of charcoal fines, agricultural residues, sawdust and coal.

76

Figure 25: Structure of analysis of the impacts of replacement amongst fuels.

4.2 Tools

4.2.1 Projection of demand Demand for cooking energy is a function of family income, number of residents in a

residence and prices of fuels and stoves, all represented in equation xii, applied separately for

each kind of fuel (Fitzgerald et al., 1990).

),,,,,( ikijikijii AAPPNYfQij = Equation xii

in which,

Qij consumption of energy j used per residence i

Yi household income of residence i

Ni number of persons in residence i

Pij price of fuel j available to residence i

Pik price of competitor fuel k, also available to residence i

Aij price of stove with the use of fuel j

Aik price of stove with the use of competitor fuel k

New investments

Scenarios GGs, PAG

Emissions factors

Technologies: efficiency, yield, PCI, etc

Percentage use of technology/fuel

Energy demand and consumption

Investments

End use of the energy: cooking of food

Demand projection

Consumption of useful energy per capita: 1GJ/year

Population estimates

77

Due to the lack of sufficient information to quantify all of the variables, Equation xiii

will not be used in this work. As a replacement, a mathematical description will be used,

employing the use of energy efficiency ratios for the fuels studied. The energy efficiency ratio

(EER) is a simple methodology which is extensively used in technical analyses of fuel

substitution. The principal hypothesis of the methodology is that consumption of useful

cooking energy is constant for all people, without restriction of income classes. Accordingly,

consumption of energy per capita is a function of efficiency of stoves. The mathematical

expression of the model is the following:

kQQE iijjÚtil =×=×= ηη Equation xiii

where:

Euseful useful energy consumption per capita for cooking, considered as a constant equal to 1

GJ/year.

Qj, ? j consumption and efficiency of stove for fuel j

Qi, ? i consumption and efficiency of stove for fuel i

The fuels considered in this analysis are: charcoal in traditional and efficient stoves,

kerosene and LPG.

So if fuel i is replaced by fuel j, the demand for fuel j46 (Qj) is equal to:

ij

ij QQ ×=

ηη

Equation xiv

Total demand for useful cooking energy (Euseful, total), is calculated as the product of the

consumption of useful energy per capita for each fuel j, and the number of the population (P),

as presented in Equation xv.

jjusefultotaluseful QPEPE η××=×= ∑, Equation xv

46 In the case of consumption of charcoal, a factor of 1.2 is applied in order to compensate for losses from the

charcoal, like fines during production and handling.

78

So total consumption of cooking energy (Qtotal) is calculated by Equation xvi

∑×

=j

usefuljtotal

EPQ

η Equation xvi

where:

Pj is the number of the population that uses fuel j.

According to the 2002 demographic census, Dar es Salaam has a population of

2,497,940 inhabitants and 596,264 residences, this being equivalent to an average of 4.2

residents per residence. The annual rate of population growth was 4.3% between 1988 and

2002. In former years, the population grew at an average rate of 7.8% per year. The

population of Dar es Salaam tripled between 1978 and 2002, as presented in Table 28.

Table 28: Trend in the population of Dar es Salaam between 1967 and 2002 Year 1967 1978 1988 2002 Population 356,286 843,090 1,360,850 2,497,940

Source: NBS (2004)

Neubauer (2002) suggests that the rate of growth declines following the year 2005, as

happened in other similar cities in sub-Saharan Africa, from 4.3% to 3.5% between 2005 and

2010, and will decline to 2% following 2010. Therefore the population is estimated by

Equation xvii

( )toPP α+= 1 Equation xvii

in which:

P population in the reference year (2002);

a annual rate of population growth;

t number of the year within the projection.

Using Equation xvii and the rates of population growth from Neubauer (2002), the

population projection is as is presented in Figure 26. In comparison with the projection of the

Tanzania National Bureau of Statistics (NBS), the projections show the same growth

79

behaviour. Average values between the two projections will be used in the estimates of

energy demand.

Figure 26: Projection of population between 2002 and 2025.

0

2

4

6

2002

2006

2008

2010

2012

2014

2016

2018

2020

2022

2024

Pop

ulat

ion

[mill

ions

of i

nhab

itan

ts]

NBSProjection

Calculatedprojection

Using Equation xv above, Table 29 presents the projection of demand for useful energy

from 2005 to 2025, in five-year intervals.

Table 29: Projection of demand for useful cooking energy 2005 2010 2015 2020 2025 Demand (GJ) 2,717,281 3,237,563 3,760,414 4,312,024 4,883,748

4.2.2 Greenhouse gases estimates In this part, one seeks to present estimates of greenhouse gas emissions, in consumption

of charcoal and in that of LPG and kerosene. Such estimates are made using the emissions

factors recommended by the IPCC.

Carbon emission

Carbon emissions (Ecarbon) are functions of consumption (Q) and of the emission factor

of a combination of stove and fuel. The estimates of carbon emissions are calculated by

Equation xviii below. The oxidation of LPG and kerosene during combustion is

approximately 100%, thus producing a relatively minor quantity of carbon.

factorcarbon EQE ×= Equation xviii

in which

Ecarbon carbon content expressed in GgC;

Q energy consumption in terajoules TJ; and

80

Efactor carbon emission factor, expressed in tonne of carbon per terajoule, tC/TJ,

equivalent to 22.7 for charcoal (IPCC, 1996).

Emissions of carbon dioxide gas (CO2)

CO2 emissions are calculated as the sum of emissions for consumption of charcoal,

kerosene and LPG, through Equation xix.

LPGCOoseneCOcharcoalCOCO EEEGG ,ker,, 2222++= Equation xix

The consumption of wood in the production of charcoal is considered non-sustainable,

since only 1/3 of the wood used in charcoal production is recovered per year (Malimbwi,

2001). Thus CO2 emissions, which contribute to the GG inventory, will be considered as 2/3

of all emissions due to charcoal consumption and calculated via Equation xx below.

MEE rcharcoalCO ×=2

Equation xx

where

Er ratio of CO2 emissions in relation to the carbon produced (CO2-C/C) as presented in

Table 30;

M molecular weight ratio for CO2/C (44/12).

Emissions of methane, carbon monoxide and nitrous oxide (CH4, CO and N2O).

The emissions of CH4, CO and N2O from consumption of charcoal, are also functions of

the quantity of carbon47 produced and are calculated by Equation xxi below.

MEEE rcarbonCOCH ××=,4 Equation xxi

where

Er emission ratio in relation to the carbon produced (CH4-C/C, CO-C/C), as presented in

Table 30;

M molecular weight ratio for CH4 (16/12) and CO (28/12).

Emissions of N2O are calculated by Equation xxii

47 Only 87% of the charcoal goes through oxidation during the burning; the rest is left over as carbon.

81

MENEE rrcarbonON ×××=2

Equation xxii

where

Nr N/C ratios for emissions of N2O (N/C).

Er ratio of emissions in relation to the carbon produced, on the basis of nitrogen (N2O-

N/N), as presented in Table 30.

M molecular weight ratio for N2O (44/28),

Table 30: GG emission coefficients and factors

N/C CO2 CH4-C/C CO-C/C NOx-N/N N2O-N/N Charcoal 0.010 1.000 0.0014 0.06 0.121 0.007 Charcoal production 0.010 1.000 0.0630 0.04 0.094 0.007

Source: IPCC (1996)

The emissions of CO2, CH4, N2O and CO due to consumption of LPG and kerosene, are

functions of consumption and emissions factors, calculated by Equation xxiii.

rCOONCHCO EQE ×=,,, 242 Equation xxiii

in which

Q LPG or kerosene consumption [PJ]

Er emission factors for CO2, CH4, N2O and CO, presented in Table 31.

Table 31: Greenhouse gas emission factors for kerosene and LPG [Gg/PJ]. CO2 CH4 NOx N2O CO Kerosene 71.50 0.0050 0.051 n/a 0.013 LPG 63.01 0.0011 0.047 n/a 0.010

Source: IPCC (1996)

Total greenhouse gas (GG) emission is the sum of all of the emissions of CO, CO2, CH4

and N2O due to consumption of charcoal, LPG and kerosene, calculated by Equation xxiv.

∑=

=n

ijiGGGG

1, Equation xxiv

in which

GGi,j greenhouse gas emission i due to fuel j.

82

4.2.3 Concentration of carbon monoxide gas and particulate matter

The emissions of CO and of particulate matter (PM10) are estimated through the use of

the TSP emissions factors presented by Smith (2000), in Table 13. These estimates are no

more than indicators, and are not necessarily correct, given that there are probably differences

between the emissions factors presented by Smith (2000) and the actual factors for the stoves

used in Tanzania. In addition to this, the calculations of the concentrations and doses of CO

and TSP are more complex, as was presented in Section 2.4.2.

CO emissions will be estimated by Equation xxv below, using the CO emissions factors

presented by Smith (2000) in Table 14.

∑=

×=n

niiCO EQEmissions

1

Equation xxv

in which:

Qi annual consumption of fuel i [kg]

Ei CO dose emission factor for fuel i [g-CO/kg].

The annual dose of CO per person is expressed by Equation xxvi below.

VPE

Dose COCO ××

=365

Equation xxvi

In the same way, total PM10 emissions per year are calculated by Equation xxvii below.

This estimate considers that all total suspended particles (TSP) are PM10, those which cause

greatest damage to health.

∑=

×=n

niiPM EQEmissions

110 Equation xxvii

where:

Qi annual consumption of fuel i [kg]

Ei PM10 dose emission factor for fuel i [g-PM10/kg].

83

The doses of PM10 per person per year are calculated by Equation xxviii below.

VPEmissions

Dose PMPM ××

=365

1010 Equation xxviii

where:

P the population exposed to the PM10 emissions, considered at around half of the

population, and the exposure time of eight hours per day.

V average volume of air breathed per person in m3, approximately 15.5 m3/day (Fischer,

2001).

4.3 Description of analysis scenarios The analysis scenarios are built based on the estimates and projections of the

percentages of consumption of charcoal, kerosene, LPG and electrical power, presented by

Malimbwi (2001), Neubauer (2002) and Mwandosya and Meena (1999). Three scenarios

were developed as alternatives for the supply of cooking energy in Dar es Salaam from the

year 2005 to 2025.

4.3.1. Scenario I: Baseline scenario

This is the business as usual (BAU) scenario, which considers change in the

composition of the energy matrix of the residential sector, following the current situation.

There is minimal possibility for major interventions to take place in the supply of cooking

energy. Penetration of efficient stoves in 2005 is estimated at around 30%, with a rate of

increase of 7% per year. Penetration of efficient stoves reaches its maximum value of 55% in

2025. Around 3% of homes will continue to use charcoal in traditional stoves, as presented in

Figure 27. The percentage of residences using kerosene increases from 23% to 29%, and the

percentage of use of other fuels (electrical power and LPG) goes from 6% to 12%.

84

Figure 27: Projection of percentages of consumers of different cooking fuels in Scenario I

0 %

20 %

40 %

60 %

2004 2008 2012 2016 2020 2024

Per

cent

age

ofco

nsum

ers Charcoal / efficient

stove /Charcoaltraditional stoveKerosene

Others (electrical)power, etc

4.3.2 Scenario II: Improved efficiency in the production and consumption of

charcoal

Scenario II is an intervention aimed at reducing demand for cooking energy, greenhouse

gas emissions and deforestation, through the use of efficient charcoal stoves and kilns. The

reduction in the consumption of charcoal may also alleviate indoor air pollution, thus

improving the health of the users. The summary of Scenario II is presented in Figure 28.

Figure 28: Scheme of hypotheses for Scenario II

Scenario II considers a possibility of increasing efficiency in the consumption and

production of charcoal during the first ten years of the period under review. The percentage of

penetration of efficient stoves is high for 20% in the first five years and later gets maintained

Health improvement

Alleviate indoor pollution

Efficient stoves: 65% Efficient kilns: 50%

Sustainable development

Reduce deforestation and GG emissions

Standardise charcoal kiln and stove

efficiency

Increase rate of penetration of efficient

kilns and stoves

Reasons

Goals (2015)

Interventions

Determinants

85

at an average rate of 10% until the year 2015. Following 2015, the percentage of penetration

declines to 60% in 2025, due to the increase in the penetration of kerosene, electrical and

LPG stoves, as presented in Figure 29. The percentage use of efficient kilns (not presented in

Figure 29) increases from 1% to 50% in 2015.

Figure 29: Projection of percentages of consumers of different cooking fuels in Scenario II

0 %

20 %

40 %

60 %

80 %

2004 2008 2012 2016 2020 2024

Per

cent

age

of

cons

umer

s

Charcoal / efficientstove

Charcoal / traditionalstove

Kerosene

Other (electrical)power, LPG, etc

4.3.3 Scenario III: Replacement of charcoal by LPG The objective of Scenario III is to reduce indoor air pollution, through the replacement

of charcoal by LPG. In addition, such a replacement will reduce the consumption of wood,

and consequently will reduce deforestation. Within this scenario, it is considered that LPG

consumption will increase over the next twenty years until it reaches 60% penetration in the

year 2025. This intervention also includes the introduction of efficient kilns in charcoal

production during the first ten years, referred to as a transition period to greater LPG use. The

summary of Scenario III is presented in Figure 30.

86

Figure 30: Scheme of hypotheses for Scenario III

LPG penetration is slow at the beginning and increases quickly after 2011. The growth

rate of penetration is 50% in the first five years and afterward declines to 40% by 2015; after

2015, the average growth rate declines to 15% per year. This projection was developed taking

into account the profile of LPG introduction in Senegal, presented in Section 3.2.1, which has

socio-economic characteristics similar to those of Tanzania. The percentages of coal and

kerosene use increase up to maximum values in 2010, and after 2010 decline to 20% each in

2025, as presented in Figure 31.

Figure 31: Projection of percentages of consumers of different cooking fuels in Scenario III

0 %

20 %

40 %

60 %

2004 2008 2012 2016 2020 2024Per

cent

age

of c

onsu

mer

s

/Charcoalefficient stove /Charcoalefficient stoveKerosene

LPG

4.4 Results This part presents results from the estimates of demand for cooking energy,

consumption of primary energy sources, greenhouse gas emissions and indoor air pollution.

Health improvement and reduced drug costs

Reduce indoor pollution

Sustainable development

Reduce deforestation

Specify LPG and gas stove quality, safety

Promote importation and consumption of LPG and

gas stoves, subsidies

60% of subsidy attributed to LPG

Reasons

Goals (2025)

Measures

Determinants

87

The estimates in each one of the three scenarios were calculated using an analysis model in

Microsoft Excel, developed based on tools presented in Section 5.2.

4.4.1 Demand for cooking energy As seen in Figure 32, in Scenario I demand for cooking energy increases progressively

from 10 PJ to 14 PJ in 2025. In Scenarios I and II, demand is equal in 2025; however in

Scenario II, it increases with relatively lesser rates in the first years. Since total consumption

is cumulative, in 2025 the area under the curve in Scenario II is smaller than in Scenario I.

The replacement of charcoal by LPG in Scenario III is shown to be a more effective

intervention for energy conservation. Within this scenario, demand increases in the first five

years and afterward falls, when the adoption of LPG begins to grow in greater volumes;

however, it once again grows after 2020 in line with population growth, until reaching the

maximum value of 11 TJ in 2025.

Figure 32: Projection of demand for cooking energy.

8

10

12

14

2005 2009 2013 2017 2021 2025

Dem

and

[PJ] Baseline

EfficiencyimprovementSubstitution byLPG

4.4.2 Consumption of primary energy

Efficiency in the consumption of charcoal

The efficiency of charcoal consumption is calculated by Equation xxix

%100×=final

usefulnconsumptio E

Eη Equation xxix

in which

Euseful the consumption of useful energy coming from charcoal;

Efinal the consumption of charcoal through the use of efficient and traditional stoves, in

proportions a and ß.

88

In Scenario I, overall efficiency increases in a linear manner up to the maximum value

of 29.5% in 2025, while in Scenario II efficiency increases logarithmically in the first ten

years, reaching the maximum value of 30% in 2017 and remaining constant until 2025. In

Scenario III, efficiency increases from 23.8% to approximately 29% in 2025, as presented in

Figure 33.

Figure 33: Trend in efficiency in charcoal consumption, 2005-2025.

22 %

24 %

26 %

28 %

30 %

2005 2009 2013 2017 2021 2025

Eff

icie

ncy

Baseline

EfficiencyimprovementSubstitutionby LPG

In Scenario I the demand for charcoal increases progressively up to the maximum value

of 10 TJ/year in 2021. In Scenario II, the rate of increase in demand declines in the first years;

after 2012 demand begins to increase at a constant rate until reaching the maximum value of 9

TJ/year in 2025, as presented in Figure 34. With the replacement of charcoal by LPG in

Scenario III, demand for charcoal declines to 3 TJ/year in 2025.

Figure 34: Projection of demand for charcoal

2

4

6

8

10

2005 2009 2013 2017 2021 2025

Con

sum

ptio

n [P

J]

Baseline

Efficiencyimprovement

Substitutionby LPG

Overall efficiency in the production and consumption of charcoal

Overall efficiency in the production of charcoal through the use of both traditional and

efficient kilns, is calculated by Equation xxx.

89

%100×+

×+×=

βαηβηα

η ltraditionaefficientproduction Equation xxx

in which,

?efficient, ? traditional efficiencies of efficient and traditional kilns respectively;

a, ß proportions of use of the efficient and traditional kilns respectively.

In Scenario I, the maximum efficiency value is 18% in 2025. In Scenarios II and III, use

of the efficient kilns increases to 50% in ten years, reaching 35% efficiency, considered the

maximum in the charcoal production process.

Figure 35: Trend in efficiency in charcoal production, 2005-2025

15 %

20 %

25 %

30 %

35 %

2005 2009 2013 2017 2021 2025

Eff

icie

ncy

Baseline

EfficiencyimprovementSubstitution byLPG

In Scenario I, the consumption of wood in the production of charcoal increases from 46

PJ/year, to the maximum value of 58 PJ/year in 2020, and afterward falls to 54 PJ/year in

2025. With the introduction of efficient kilns in Scenario II, consumption of wood falls to 27

PJ/year in 2025. In Scenario III, wood consumption falls to 7 PJ/year, as presented in Figure

36.

Figure 36: Projection of wood consumption in the production of charcoal

0

15

30

45

60

2005 2009 2013 2017 2021 2025

Con

sum

ptio

n [P

J/ye

ar]

Baseline

Efficiencyimprovement

Substitution byLPG

Overall efficiency (?global) is the product of the efficiency of production and efficiency

of consumption of charcoal, or the efficiency of conversion of wood to charcoal, and lastly,

into useful energy as presented in Equation xxxi.

90

%100×=woodtheofprimary

cookingforusefuloverall E

Eη Equation xxxi

The maximum value for efficiency of conversion of wood into useful energy is only 6%

in Scenario I, while in Scenarios II and III it stays around 10%.

Figure 37: Overall efficiency in the conversion of wood into useful energy

2.5%

5.0%

7.5%

10.0%

12.5%

2005 2009 2013 2017 2021 2025

Ove

rall

effic

ienc

y Baseline

Efficiencyimprovement

Substitutionby LPG

4.4.3 Emission of greenhouse gases

Emissions of carbon dinoxide gas (CO2)

As it is the most important of the greenhouse gases, the emissions of CO2 are

calculated as the total of emissions in the consumption of charcoal, kerosene and LPG and in

the production of charcoal. Looking only at consumption of the energy products,

( oseneCOLPGCOcharcoalCOCO EEEE ker,, ,2222++= ), the CO2 emissions are higher under Scenarios I

and II, reaching the value of 800 GgC/year in 2025. However, the cumulative quantity (the

area under the curve) of emissions under Scenario II is less than in Scenario I. The

replacement of charcoal by LPG reduces emissions to less than 700 GgC/year, as presented in

Figure 38.

Figure 38: Carbon dioxide gas emissions in the consumption of cooking fuels.

500

600

700

800

900

2005 2009 2013 2017 2021 2025

Em

issi

ons

[GgC

] Baseline

Efficiencyimprovement

Substitutionby LPG

91

Looking at CO2 emissions in the consumption of charcoal, kerosene and LPG and in

the production of charcoal ( ), the

replacement of traditional stoves in Scenario II reduces emissions to half of the projections in

Scenario I, and they are less than 1500 GgC/year in Scenario III, as presented in Figure 39.

Figure 39: Carbon dioxide gas emissions in the consumption of energy products for cooking and in the production of charcoal.

1000

3000

5000

7000

2005 2009 2013 2017 2021 2025

Em

issi

ons

[GgC

]

Baseline

Efficiencyimprovement

Substitutionby LPG

Emissions of greenhouse gases (CO2, CH4 and N2O) are calculated, including those

for the production of charcoal. These emissions, with CO2 being predominant, are greater in

Scenario I, while in Scenario II they decline to only 3 thousand GgC/year in Scenario II, and

to 1.5 thousand GgC/year under Scenario III, in 2025.

Figure 40: Projection of greenhouse gas emissions.

0

2

4

6

2005 2009 2013 2017 2021 2025

GG

s [’

000

GgC

] Baseline

Efficiencyimprovement

Substitution byLPG

4.4.4 Concentrations of carbon monoxide gas and particulates. Carbon monoxide gas

In Scenarios I and II, the concentrations of CO per capita decline slowly from 40 g/m3

to 25g/m3 in 2025. Replacing charcoal by LPG in Scenario III, the levels of concentration of

the emissions fall progressively to less than 10 g/m3 after the year 2023. This estimate,

however, does not include CO emission in the production of charcoal, and it was considered

92

that half of the population of the city is constantly exposed to indoor air pollution for eight

hours a day.

Figure 41: Concentrations of CO per capita in [g/m3].

0

15

30

45

2005 2009 2013 2017 2021 2025

Con

cent

rati

ons

of C

O

[g/m

3]

Baseline

Efficiencyimprovement

Substitutionby LPG

Recommended standard

Total suspended particles (TSP).

The concentrations of TSP per capita are greater in Scenarios I and II, declining from

340 µg/m3 to 230 µg/m3 in 2025. With the introduction of LPG in Scenario III, the

concentrations per capita decline constantly to less than 100 µg/m3 in 2025. All of the total

suspended particles (TSP) were considered as being less than 10 micrometres (PM10), capable

of causing adverse health effects.

Figure 42: Concentration of TSP per person [µg-PM10/year].

0

100

200

300

400

2005 2009 2013 2017 2021 2025

Con

cent

rati

on o

f P

M10

[µ

g/m

3/ca

pita

]

Baseline

Efficiencyimprovement

Substitution byLPG

Standard

4.5 Discussion

This part presents the discussion on the results of the analysis as obtained in Section

4.4. It presents a discussion on the costs of LPG and what investments would be needed to

promote its use. On the demand side, one seeks to analyse the costs of LPG within the

93

household budget, presenting a short comparison of prices with charcoal and kerosene. Also

discussed are greenhouse gas emissions and concentrations of carbon monoxide gas and total

suspended particles.

4.5.1 Savings in the use of efficient stoves and replacement of charcoal

Savings in energy costs is the important factor in the choice of fuel. This part analyses

the savings through the use of efficient stoves, and the additional costs of using LPG (with tax

exemption) instead of charcoal in traditional stoves. Nonetheless, the analysis does not

consider all of the factors presented in Section 2.5.2 which determine the choice of a cooking

fuel. Savings in the consumption of a fuel corresponds to savings in terms of expenditures on

same. However, the replacement of technologies and cooking fuels may increase energy costs

and expenditures.

Replacement of the traditional charcoal stoves by the more efficient ones

Looking at a family of five persons, which consumes 840 kg/year of charcoal (168

Kg/year per capita), the use of an efficient stove may reduce consumption to 560 Kg per year.

On the assumption of a charcoal price of 0.12 USD/Kg, the use of an efficient stove may

result in savings of 36.00 USD/year. This means a payback period of less than two months for

the Tanzanian efficient stove, which costs between 3.5 and 4.5 USD, and has no operating

costs.

Using per capita expenditure information in Table 18 and consumption of useful energy

per capita of 1 GJ/year, one observes, in Figure 43, that the percentage of expenditures for

charcoal with use the efficient stoves declines significantly in the quartiles Q1 (42% to 28%),

Q2 (27% to 18%) and Q3 (19% to 13%) of the population in Dar es Salaam. For the quartiles

Q4 and Q5, the percentages of expenditures for charcoal are less than 10% when the efficient

stoves are used. For the consumers in the Q5 quartile, there will not be any major difference

in the proportion of expenditures on charcoal or in the use of the efficient or traditional

stoves.

94

Figure 43: Percentage of expenditures for charcoal by quartiles.

0 %

15 %

30 %

45 %

Q1 Q2 Q3 Q4 Q5

Per

cent

age

of

Exp

endi

ture

s Traditionalstove

Efficientstove

of 10%expenditures

Replacement of charcoal by LPG

Replacing charcoal by LPG in cooking involves the purchase of a gas stove, and

periodically LPG purchase and stove maintenance costs. Looking at a family of five people,

and consumption of 5 GJ/year of useful energy, the use of LPG for cooking increases

expenditures48 for energy to 158.5 USD/year and 218 USD/year, for LPG prices with and

without tax exemption. Even with tax exemption, the price of the useful energy with LPG

consumption is still greater than the price of using charcoal, as presented in Table 32.

Table 32: Costs of use of LPG with prices net of taxes.

Fuel Price to the consumer [USD/Kg]

Cost of useful energy [USD/MJ]

LPG (without taxes) 0.86 0.040

LPG (with taxes) 0.12 0.030

Charcoal (traditional stoves) 0.086 0.020

Charcoal (efficient stoves) 0.086 0.010

One should observe, in Figure 44, that the percentage of family expenditures for LPG

will be greater than the monthly expenditure of the population in quartile Q1, presented in

Section 4.1. Even with tax exemption, the percentage of expenditures is around 70% of

household expenditures, considered greater than the acceptable value of around 5 to 10%. The

percentage of expenditures for LPG approaches the amount of 10%, only for the population in

quartile Q5.

48 The life-span of a gas stove costing 70 USD was considered at around ten years. The expenditures are current

costs of LPG and of the gas stove, and are distributed equally during the first ten years of analysis.

95

Figure 44: Percentage of expenditures for LPG, with and without taxes

0 %

30 %

60 %

90 %

120 %

Q1 Q2 Q3 Q4 Q5

Perc

enta

ge o

f E

xpen

ditu

res

GLP semimpostos

LPG with tax

Charcoal inefficient stoves

of 10%expenditures

4.5.2 Greenhouse gas emissions

The replacement of charcoal by LPG is the most effective solution in the long term, in

order to reduce the greater part of the greenhouse gases arising from the burning of charcoal.

The use of efficient stoves is effective in the short and medium term. However, the use of

charcoal in Dar es Salaam emits a relatively minor quantity of greenhouse gases in

comparison with other countries, as presented in Table 33. As such, the use of charcoal in Dar

es Salaam does not show up as a potential target in the strategic plans for reducing emissions

of the gases on a world scale. Nevertheless, as happens in Kenya, emissions from the

production of charcoal may be significant on the national level.

Table 33: Comparison of greenhouse gas emissions in the production of charcoal in Tanzania, in Mt.

Prod’n CO2 CH4 N2O Tanzania (1990) 0.74 10.3 0.240 0.0003

Dar es Salaam (Estimates for 2005) 0.26 5.3 0.110 0.00024 Kenya charcoal production (1996) 2.20 3.1 0.097 0.00032 Brazil charcoal production (1996) 6.40 8.6 0.310 0.00028 Kenya: use of fossil fuels (1995) 6.7 - -

Brazil: use of fossil fuels 249.0 - - United States: use of fossil fuels 5490.0 10.09 0.269

CEEST (1997), Pennise et al. (2004) and own estimates.

4.5.3 Concentrations of CO and PM10

This study is limited to quantification of the CO and PM10 emissions, in order to

estimate the benefits which may be realised through one of the interventions. The

concentrations of CO and PM10 are converted into effects on health, through epidemiological

concentration response functions, ECRF (Fischer, 2001). These functions are used in order to

quantify the effects in terms of diseases and infections, such as mortality, chronic bronchitis,

respiratory symptoms, etc. It’s worth mentioning as well that the levels of concentration may

vary significantly from the estimated values, due to uncertainties in the methodology used.

96

There is no great difference between quantities of carbon monoxide gas emissions in

Scenarios I and II, as long as charcoal continues to be used in the two scenarios. In Scenarios

I and II, the concentrations of CO in 2025 are four times greater than the standard

recommended by the WHO and EPA. In 2005, they decline to a value three times greater, still

a level which is higher than the recommended value. Only in Scenario III where the levels of

concentrations of CO may be reduced to the recommended standard.

Like for CO, the concentrations of TSP per capita will continue being higher in

Scenarios I and II, by factors of seven and six times greater than the values recommended by

the WHO and EPA. In Scenario III, emissions will fall to less than 100 µg/m3 over the year, a

value still two times higher than that recommended. During the period of this analysis, this is

the best result which may be realised, given that 10% of the population will still continue

using charcoal.

4.5.4 Imports of LPG and its impacts on Tanzania’s economy

The objective of this part is to show the impacts of replacing charcoal by LPG on the

national level. The first hypothesis of the analysis is that all LPG used in Tanzania is

imported, according to its price on the international market. The analysis only includes costs

of fuels and does not include purchases of stoves and their operating costs.

Imports of LPG and the balance of payments

According to TaTEDO (2002), LPG consumption in Tanzania in 2001 was 3.6

thousand tonnes, while AFREPREN (2004) estimates this value as around 5.0 thousand

tonnes in 2002. To replace 60% of the current demand for cooking energy, 100 thousand

tonnes of LPG will be necessary. This means an increase of twenty times in the annual LPG

demand in the country, and is an increase of 47 million USD/year, with the average price of

470 USD/t. This value represents approximately 2.5% of the current value of Tanzania’s

imports.

Taking into account the government’s most recent initiatives in the promotion of LPG

consumption, the current consumption of LPG may be increased to 5.0 thousand tonnes. The

97

FOB price49 of the LPG in Dar es Salaam in 2001 was 470 USD/t, and the current value of

LPG importation is around 1.69 million USD. In the event of LPG prices increasing at a

constant rate of 6.4%/year 2004 (UNDP/World Bank, 2004), the value of LPG imports in

2004 will be 2.5 million USD.

In order to project the values of imports, the historical values for imports are

extrapolated in order to determine the values in the future. The extrapolation is limited to a

five-year period, from 2005 to 2010, in order to reduce errors in the results. Even so, this

methodology does not ensure great precision and confidence in the results, and was used only

as a simple solution for projection purposes, given that the import and export values are

highly variable, depending upon micro- and macro-economic situations. Tanzania’s import

and export values, presented in Figure 45 confirm polynomial functions with coefficient R of

0.65 and 0.60 respectively.

Figure 45: Trend and projection of Tanzania’s exports and imports, 1995-2010.

0

1000

2000

3000

4000

1995

1997

1999

2001

2003

2005

2007

2009

Impo

rts/

Exp

orts

[mill

ion

USD

]

01

23

45

6L

PG

Im

port

s [m

illio

ns o

f U

SD]

Exports

Imports

Imports of LPG

)Poly. (Exports

)Poly. (Imports

When projected over the next five years, the curves cross in 2009 when the value of

imports is equal to the value of exports, at around 2,570 million USD . The increase in LPG

consumption in 2005, in Scenario III, will be 1,340 t, equivalent to 0.7 million USD, and the

total amount of imports is projected at around 1,913 million USD . The value of LPG imports

this year will be only 0.04%, insignificant in relation to the value of the country’s imports. In

the same way, imports of LPG will be 5.7 million USD in the year 2010, still representing a

minor proportion in the projected values of imports. One concludes, therefore, that imports of

49 The Free On Board price is the price of the merchandise landed at the port of the destination country, including

freight, insurance and customs duties costs.

98

LPG will not increase the country’s import values significantly50 at least in the first five years

of adaptation to high use of LPG.

Tax exemption

The price of LPG is constituted up to 60% by taxes and margins of the distribution

companies, in proportions of 40% and 20% respectively. More recently, the reduction of

customs duties of 0.11 USD/Kg of LPG, reduced the proportion of taxes to 30%. In order to

increase LPG consumption even more, the government of Tanzania could provide exemption

on taxes to LPG and gas stoves, at least in the first ten years, as happened in Senegal. Tax

exemption will reduce the price of LPG to 0.72 USD/Kg, which is relatively more affordable

for the consumers. On the other hand, this will mean a reduction in the government’s

collections.

The projection for the collections is 1,300 million USD in 2005 (Bank of Tanzania,

2004), and tax exemption for the importation of LPG, of around 30%, will be 0.53 million

USD. The exemption represents less than 0.04% of all collections. Its value increases as LPG

consumption increases, until reaching the value of 34 million USD in 2015, representing the

proportion of 2.3% of the collection. These exemption values are still minor when compared

to the collections, and one may conclude that the effect of tax exemption on the sale of LPG

will not be significant for the country’s finances, as presented in Figure 46.

Figure 46: Projection of collections and exemptions on the sales of LPG.

0

5 0 0

10 0 0

15 0 0

2 0 0 0

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

Impo

rts/

Exp

orts

[mill

ion

USD

]

0

10

2 0

3 0

4 0

LP

G I

mpo

rts

[mill

ions

of

USD

]

Collection

Exemption forLPG.Geom)Collection(

50 Normally, when the import value is greater than that of export, a payments crisis occurs in the country. The

effect of a negative balance of payments is that the country will not have any way to pay for imports and other international debts. As a result, the country will need loans or to defer payment of the debts, thus accumulating more interest and foreign debts.

99

Direct subsidies to LPG prices

In order that LPG be affordable for the majority of the population, a further price

reduction will be necessary, possibly through application of subsidies. This intervention

depends very much on the government’s policies, given that subsidies are very expensive and

will be needed for more than 80% of the population. Taking into account the percentage of

around 10% of expenditures, the quartile Q1 families, with monthly expenses of around 195

USD/year, need an approximately 98% subsidy on the current price of LPG. The cost for a

family of five persons of using LPG is 152 USD/year and 211 USD/year, with and without

tax exemption respectively. In both cases, only quartile Q5 of the population will not need a

high quantity of subsidy, as presented in Figure 47. Around 480 million USD are needed as a

subsidy to cheapen LPG, in the event of the taxes being built into the price of the LPG, and

320 million USD in the case of the taxes being taken from the end prices of the LPG. The 320

million USD represent 18% of the recurrent expenditures and approximately all of the

Tanzania government’s costs in the high-priority sectors like education, health, transport and

agriculture.

Figure 47: Percentage of subsidies needed for various expenditure quartiles.

0 %

20 %

40 %

60 %

80 %

100 %

Q1 Q2 Q3 Q4 Q5

Per

cent

age

of s

ubsi

dy

0

100

200

300

400

500

Subs

idie

s [m

illio

n U

SD]

LPG withouttaxes

LPG with taxes

Price subsidyw/o taxes

Price subsidywith taxes

100

Chapter 5

Conclusions and recommendations.

There will not be a significant fall in demand for cooking fuels due to improved

efficiency in consumption of charcoal during the period under review. However, in Scenario

II, wood consumption is significantly reduced by the introduction of efficient kilns, by more

than half of current consumption. In order to avoid deforestation, the combination of

improved efficiency in charcoal production, and at the same time increased LPG

consumption, will have the best result. Charcoal consumption in Dar es Salaam, however, is

not the cause of deforestation. However, if the annual rate of penetration of the efficient

stoves continues the same, there will probably not be equilibrium between use of wood and

reforestation over a twenty-year period, as long as the rate of use of wood is greater than that

of reforestation. The increase in distances between the points of charcoal production and the

city, in line with this hypothesis that deforestation increases more and more in the areas close

to the city.

The greater part of the charcoal in Dar es Salaam comes from the first-growth forests

with no reforestation programs, therefore its use contributes to the greenhouse gas inventory.

Even if the harvesting were sustainable, the production and use of charcoal emit incomplete

combustion products such as methane and benzene, which contribute to the accumulation of

greenhouse gases. The whole chain of production, transport and end use of charcoal emits a

larger quantity of CO2 than other fuels, including the fossil fuels. With the ever-greater

increase in the distance between the points of charcoal production and the city, CO2 emission

increases in the component of charcoal transport, due to the consumption of more diesel and

gasoline. Therefore a reduction in the consumption of charcoal may reduce a large quantity of

greenhouse gas emissions.

101

The burning of charcoal, in addition to carbon monoxide gas, produces suspended

particles which are harmful to health. Air pollution through charcoal use is large, both in the

traditional stoves and in the efficient stoves. There is no quantitative information on the

effects of pollution on health due to the burning of charcoal in Dar es Salaam. Research

efforts undertaken in China, India and Kenya, however, show a strong link between indoor air

pollution and acute respiratory infections. In addition to causing ill health, indoor air pollution

affects the household economy, security, hygiene and environment. Exposure to this kind of

pollution increases ever more amongst poor families, inasmuch as the preference increases for

cheaper fuels like charcoal and firewood. While the consumption and production of charcoal

produce a large quantity of gaseous and particulate air pollutants, LPG and kerosene burn

with relatively lower indices of pollution.

In spite of the lack of information on the effects of CO and PM10 emissions in Dar es

Salaam, it’s clear that the dimension of exposure and the effects on health depend on air

circulation in the kitchen. The concentrations may be reduced through improvements in the

stove’s combustion and in the kitchen’s ventilation. For example, cooking close to a open

window or in a well-ventilated spot may significantly reduce the concentration of the

emissions. This is already practised by some users of charcoal in Dar es Salaam (personal

communication with E. N. Sawe, Director of TaTEDO); however, there is no information on

the popularity of this practice and whether it is part of or is recommended in the use of

charcoal stoves.

Charcoal is a cheaper alternative for cooking, in relation to the other commercial fuels,

thus ensuring its existence in residential consumption in Dar es Salaam for some time yet in

the future. On the other hand, the use of LPG and kerosene for cooking is still expensive for

the majority of families in Dar es Salaam, and thus its adoption becomes a more unlikely

alternative in the short term, since there is no expectation of an abrupt improvement in the

levels of family income in Tanzania. The replacement of charcoal by LPG or kerosene,

therefore, will not occur by reason of low costs, but due to the desire of the users to improve

their quality of life, within the context of modernisation.

Despite the availability of LPG in Dar es Salaam, there has not been major penetration

in its consumption. Nevertheless, a recent decision by the government of Tanzania to reduce

taxes on the price of LPG was a fruitful intervention in promoting its use. This positive result

102

suggests the importance and need for subsidised promotion of LPG. Exemption from taxes

alone is insufficient to make the prices of LPG affordable for the users. In Senegal, for

example, despite the Customs exemption on LPG and its stoves, its consumption did not

increase until when a subsidy was introduced. The application of subsidies will probably be

necessary in order to promote LPG consumption in Tanzania.

Still, a major concern in subsidy programs is how to apply them in such a way that

ensures their benefits to all users, at all income levels. None of the subsidy programs studied

proved to be effective in the promotion of LPG and kerosene. Subsidy programs face

challenges to ensure equality in distribution of their benefits and to control end use of the

subsidised fuels. In India, for example, only high-income-level families have access to

subsidised LPG and kerosene, and thus the subsidies have no impacts on the improvement in

the quality of life of the poor. In addition to this, up to 50% of subsidised kerosene is diverted

to non-residential use, like adulteration of diesel and gasoline. Due to the lack of oversight,

this fraud not only prevents the consumers from reaping the benefits of using cleaner fuels,

but also involves higher costs for the public treasury.

The use of domestic energy resources like bio-mass is of interest to the Tanzania

government, since it avoids imports in foreign currency. Growth in demand for LPG and

kerosene may increase the value of imports and disturb the country’s balance of payments.

With a less developed economy, the government’s priority is probably on other more

important areas like health, education, agriculture and transport. While there is no possibility

of increasing LPG consumption radically, it is important to improve efficiency in supply and

use of charcoal, which is presently the most important cooking fuel.

103

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