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RENEWABLE ENERGY ASSESSMENT REPORT
FOR
GLOBAL TEA COMMODITIES LIMITED
March 2012
Kenneth Gondwe Lasten Mika Practical Action
2
CONTENT
1 EXECUTIVE SUMMARY .................................................................................................................. 3
2 INTRODUCTION ............................................................................................................................ 4
3 ENERGY CONSUMPTION ............................................................................................................... 5
3.1 ENERGY CONSUMPTION..................................................................................................................................... 5
3.2 PRIOR ENERGY ALTERNATIVE EFFORTS .................................................................................................................. 9
3.2.1 Past Energy Alternatives ............................................................................................................................. 9
3.2.2 Energy management ................................................................................................................................... 9
3.3 HEAT CONSUMPTION ........................................................................................................................................ 9
3.4 POWER CONSUMPTION AND DEMAND .................................................................................................................. 9
3.5 ENERGY AND DEMAND PRICES........................................................................................................................... 10
4 ENERGY SUPPLY OPTIONS ........................................................................................................... 10
4.1 MAKANDI ESTATES ......................................................................................................................................... 11
4.2 KAWALAZI ESTATES ........................................................................................................................................ 11
4.3 NGAPANI ESTATES ......................................................................................................................................... 12
5 ENERGY PROPOSALS ................................................................................................................... 14
6 RECOMMENDATIONS ................................................................. ERROR! BOOKMARK NOT DEFINED.
7 CONCLUSION .............................................................................. ERROR! BOOKMARK NOT DEFINED.
8 REFERENCES ............................................................................................................................... 21
9 ANNEX I: ESTIMATING POTENTIAL HEP GENERATED AT LICHEREMU WATER SYSTEM.................... 22
10 ANNEX II: RENEWABLE ENERGY OPTIONS FOR MALAWI .............................................................. 23
10.1.1 Biomass based fuels and end-use technologies ............................................................................... 23
10.1.2 Bio fuels ................................................................................................................................................... 25
10.1.3 Solar Energy .............................................................................................................................................. 25
10.1.4 Wind Energy .............................................................................................................................................. 27
10.1.5 Hydropower .............................................................................................................................................. 28
3
1 Executive Summary
Global Tea and Commodities (GTC) Ltd was established in 1992 in the UK, where its headquar-
ters remains to-date. The Company specialises in the production and trading of tea, coffee
and macadamia nuts and employs over 12,000 people internationally with offices in the UK,
India, Kenya and Malawi.
In Malawi, GTC employs a total of around 10,000 people and the estates support an estimated
25,000 family members. The Global Tea and Commodities (Malawi) Ltd consists of three plan-
tation companies, namely, Kawalazi Estates Company Ltd (Northern Malawi), Sable Farming
Company Ltd and Makandi Tea and Coffee Estates Ltd (Southern Malawi) – these are all whol-
ly owned by the UK Company.
An agreement was reached between Global Tea Commodities Limited and Imani Development
to use Business Innovative facility to assess the potential of development of renewable energy
resources at three GTC sites of Makandi in Thyolo District, Ngapani in Mangochi District and
Kawalazi in Nkhata-Bay District. Imani is working with Practical Action in this assessment.
An assessment of the energy options for the three estates was undertaken. A summary of the
findings and recommendations is provided among the three main proposals shown below in
table 1.
The energy options are calculated as "stand alone" proposals. If more than one proposal is
identified per site then total energy saving will be less than a simple addition of the proposals.
Estate Name Options Identified Savings/Benefits
Makandi Improved heat efficiency
Wind energy option
Firewood savings 560m3/yr
Carbon savings 789 tonnes/yr
Demand savings 2,400 kVA/yr
Total savings US$55,200
Investment Cost US$200,00
Payback 3 years
Kawalazi Improved heat efficiency
Installation of Mini Hydro Plant
Demand savings 3,600 kVA/yr
Diesel savings 91,000 litres/yr
Carbon savings 244 tonnes/yr
Total cost of savings US$85,247/yr
Investment Cost US$500,000
Payback period 6 years
4
Ngapani Grid extension Diesel savings 68,250 litres/year
Carbon savings 183 tonnes CO2 per year
Savings in maintenance + labour US$4900
Cost of grid extension US$250,000
Cost demand per year due to grid US$55,200
Net savings US$53.905
Payback Period 4.6 years
Table 1: Energy saving possibilities at GTC.
The proposed energy measures are an estimate and should undergo specific detailed technical
review and investment calculations based on tenders before final implementation. The assess-
ment found reasonable energy intervention options in all but one estate Ngapani, it is thus
recommended to carry out detailed feasibility studies on Makandi and Kawalazi Estates. The
exercise should help to collect further information to allow for detailed and specific investiga-
tions in the identified areas of intervention. At Makandi it is recommended to carry out energy
efficiency interventions and analyze the potential of the wind. At Kawalazi, it is recommended
to carry out detailed technical studies for the installation of the mini-hydro. At Ngapani, grid
extension is a feasible option and the cost benefit will be 4.6 years and will even be more prof-
itable when other economic factors are taken into consideration such as improved productivity
and welfare.
2 Introduction
The Global Tea and Commodities (Malawi) Ltd consists of three plantation companies, namely,
Kawalazi Estates Company Ltd (Northern Malawi), Sable Farming Company Ltd and Makandi
Tea and Coffee Estates Ltd (Southern Malawi) – these are all wholly owned by the UK Compa-
ny.
The three estates make up a total of around 17,000ha. All the GTC operations in Malawi have
been very successful in increasing the production per unit area since acquisition. All policy and
group-level management comes from the Group Office located at Makandi; otherwise, each
plantation has a General Manager to run the day-to-day operations.
GTC produce 17% of the tea in Malawi with 60% sold at auction and 40% to private buyers, all
the tea produced is Rainforest Alliance certified. 6.5% of this tea production comes from
smallholder farmers to a total of around 364 tonnes per year. 33% of the tea is FAIR TRADE
Certified. The tea is particularly attractive to buyers because of the low pesticide use in Malawi
and distinctive red colour. GTC are the biggest producers of coffee in Malawi with 60% of the
market and 800t of production each year. They are also the largest producers of macadamia
nuts in the country with 700t of production and 40% of the market.
GTC are committed to sustainable development at all of its sites in Malawi and have worked
towards socio-economic development through working with local communities on projects such
as education, health care, crèches and clean drinking water. GTC also have a strong commit-
ment to the environment and reducing environmental degradation at the sites through distri-
5
bution of tree saplings and education and implementation of best practice methods for farm-
ing.
Both Makandi and Kawalazi are Rainforest Alliance certified and Sable is going through the ap-
plication process, which means they adhere to strict economic and social criteria but with a
particular focus on protection of the environment and ecosystem conservation. Kawalazi is also
Fair-trade certified for both the factory and plantation tea. Although Fair-trade does consider
the environment, their key focus is on social standards for workers.
Neither Rainforest Alliance nor Fair-trade have specific criteria relating to climate change or
renewable energy, but both have released some statements. There is a climate change mech-
anism known as Reduced Emissions for Deforested and Degradation (REDD) whose objectives
are very similar to those of Rainforest Alliance.
It is their interest in working towards environmental protection and mitigating the impacts of
Climate Change that has lead GTC to discuss the potential for renewable energy systems in
Malawi. GTC are also keen to see how reduced carbon emissions from their operations could
contribute to Carbon Credits and Finance in Malawi.
3 Energy consumption
3.1 Energy consumption
The current state of energy demand and supply at each of the three estates is provided. In this
section an explanation of the state of affairs for each estate is provided.
Makandi Estate
Makandi Tea and Coffee Estates Ltd (hereafter referred to as „Makandi‟) is in the Thyolo region
of Malawi and comprises of the Chisunga and Mindale estates. The estates were purchased in
2004 and have a land area of around 4,500ha producing tea, coffee and macadamia nuts.
The tea processing factory as Makandi is one of the largest in the world under a single roof
with the capacity for processing up to 250t green leaf per day. Having such high production
capacity means that the factory also has an associated high power requirement of around
2.5MW. As well as power for the factory there are also 84 individual ESCOM connections, each
requiring a separate meter reading and costing in the region of MWK10million (approx.
US$70,000 per month). Due to unreliability of ESCOM supply and the sensitivity of the prod-
ucts, Makandi has installed standby diesel generators which are detailed in Table 3.
Table 2: Status of Standby generation at Makandi.
Generator type Existing ca-
pacity (kVA)
Proposed capaci-
ty
Remarks
Catapillar 500 N/A
Perkins 670 N/A
Detroit 1050 - To be decommis-
sioned
2 x new genera-
tors
1300 (for the
two)
To be commis-
sioned
2220 2370 Increase by 6.8%
6
The generators run for around 500 hours each year and consume on average 51,000 litres of
diesel per annum. Malawi has been experiencing scarcity of diesel in the past few months de-
spite a sharp increase in price. The issues relating to the lack of diesel in Malawi have been
escalating in recent months and are largely attributed in the media to the lack of foreign ex-
change and therefore lack of funds to import the commodity.
Firewood is an important source of energy to meet the heating needs of the factory. It is ap-
proximated that 2,800m3 of firewood is burned every year with 1m3 of wood required for eve-
ry 215kg of tea produced. Of this firewood 70% is grown and managed on estate land and
30% must be purchased from outside sources. Management reported a problem of illegal har-
vesting of timber/ firewood which has affected the yield of firewood from its own forests.
Fig 1a: Firewood storage near boiler house
Electricity needs of households are met by the national grid supplied by ESCOM. Makandi has
also already introduced improved stoves to its junior staff as well as kitchen facilities providing
food to its staff. Despite the positive outlook, power outages due ESCOM load shedding have
affected the factory operations forcing management to invest in standby generation capacity
which is at 2220kVA.
Kawalazi
Kawalazi Estates Company Ltd (Hereafter referred to as „Kawalazi‟) produce tea and Macada-
mia nuts and comprises the Kavuzi tea estate and Mzenga and Tihomane macadamia estates.
The total land area is 8400 ha and this was the first operation in Malawi purchased by GTC in
2000.
In terms of energy supply and consumption, Kawalzi Estate is on ESCOM lines. In addition it
has heat sources and apparatus for steam production. Steam from the boilers can be used to
produce electricityat Kawalazi. These are run from waste of the macadamia nuts. The pictures
below show some of the major energy generating devices at Kawalazi.
7
Fig 1 b: Thomson boiler at Kawalazi (insert macademia shell used as fuel also)
Fig 1c :Standby generator at Kawalazi Estate
8
Fig 1d: Steam turbine
Figure 8: Kawalazi factory in pictures
Sable Farming Company Ltd
Sable Farming Company Ltd (Hereafter referred to as „Sable‟) comprises the Mapanga division
in the South and the Ngapani division in the East of Malawi). The company produces coffee and
macadamia nuts on around 4,500ha of land and houses the only integrated milk and pro-
cessing diary in the country. The farms were purchased in 2000 at the same time as Kawalazi.
There is a macadamia factory, tea factory, the boiler house and junior staff houses as the main
energy consuming centers.
The key issue that has been highlighted by Sable management is the lack of ESCOM power
supply in the Ngapani region. Ngapani Estates is the only one out of the three GTC estates that
is yet to be connected to the national electricity grid. They currently rely on diesel power gen-
eration. On an annual basis, Ngapani currently require 90,000 litres of diesel each year to
power the generators at the site. The energy consumption is an equivalent of 750 MWh per
annum and it costs approximately (US$135,000) per year on diesel fuel alone. Due to current
shortages of diesel and that it is available on the parallel market makes this figure even lower.
As a result the estate is limited in the amount of processing they can do with the coffee and as
a result it is transported to Blantyre for secondary processing. The plans for the estate are to
invest in 110KW processing plant, which would employ as many as 200 workers. The power
requirements are likely to increase in the coming years as the macadamia plantations mature
and the load needed could go up to 280KW.
At Ngapani, junior members of staff reside in „villages‟ that are completely without access to
modern energy. There are 620 workers houses on the estate and these are without access to
energy. According to the management they have ambitions to improve the living conditions of
the workers by providing energy that is adequate for lighting and heating purposes. At least
they require 0.1kW (according to management) for lighting purposes.
9
3.2 Prior energy alternative efforts
3.2.1 Past Energy Alternatives
Kawalazi has high potential for hydro-electric power generation. This confirms earlier
assessments done in 1979 when the estate was being run by Malawi Government through
ADMARC. As regards household energy needs for its labourers, Makandi has already
disseminated energy saving wood stoves for junior staff houses, replacing the traditional 3-stone
cook place.
3.2.2 Energy management
There is no energy management strategy that is put in place by the company. Although meter
reading for energy and water is available, the fuel consumption is not metered. Currently the
information gathered on energy and water is mainly for accounting purposes.
3.3 Heat consumption
Biomass is a major energy source for boilers that produce process heat for the factories at both
Makandi and Kawalazi. Potentially this would be the case for Ngapani if it were to go into coffee
processing soon. Biomass is also the principal source of energy at household and institutional
levels at all the three sites. The main source of heat is biomass on all the three estates. The table
below shows the estimated heat generated at the estates for the steam boilers. All heat is
produced from biomass which was used in the steam boilers.
Heat Consumption at
each estate
Fuel Source Fuel
consumption
(m3)
Fuel
consumption
[MWh]
Percentage
[%]
Mapanga Estate Firewood 2,800 8,867
Kawalazi Estate Macadamia
nut Shells
Sable Estate None 0 0
Total 100
Table 3.1 Fuel consumption at the three GTC Estates.
Sable estate is the only one without steam production and use.
3.4 Power consumption and demand
The power sources include the ESCOM and diesel fired generators. The tables below show the
demand and consumption by the utility and the on-site generation. There are no power meters
besides the main power meter so the figures in the table below are calculated from experience.
Annual Power
consumption
[MWh]
Average
Demand
per month
(kVA)
Percentage
(%)
Makandi Estates Not given 2,500
Kawalazi Estates Not given 880
Ngapani Estates 0 0
Total 300
Table 3.2 Power consumption and demand by Estate from Utility.
Additional information is required for the energy consumption and demand at the two estates
namely Makandi and Kawalazi Estates. There is no grid available at Sable Estates and power is
considered in table below.
10
Generator Size
(kVA)
Fuel
Consumption
(litres)
Annual Power
generation
[MWh]
Percentage
(%)
Makandi Estates 2,200 51,000 496
Kawalazi Estates Not given
Ngapani Estates 218 90,000 875
Total
Table 3.3: Power consumption from on-site generators (Assume 60% combustion efficiency,
diesel 35 MJ/litre).
There is limited data for the standby generation on Kawalazi Estates for a complete analysis.
3.5 Energy and demand prices
The energy prices in Malawi for the purposes of this study are 0.016 US$/MWhpower and
105US$/MWhheat (diesel). The cost of energy demand is 23 US$/kVA.
4 Energy Supply Options In this section we analyse the energy options considered at each site. The table below uses a
qualitative assessment of the potential options that could possibly be considered during the
detailed study. The table is an indicator of the various options.
Table 4: RES options for GTC sites
Energy source or technology Status/ Availability of the energy
source/technology at the sites
Makandi Kawalazi Ngapani
1.0 Biomass Potential
1.1 Improved HH stoves √ √ x
1.2 Improved institutional stoves √ √ x
1.3 Process heating √ √ x
1.3 Biogas X x x
1.4 Briquettes X x x
1.5 Steam turbine X √ x
2.0 Solar Energy Potential
2.1 Solar PV √ √ √
2.2 Solar thermal √ √ √
2.3 Solar water pumping X x x
3.0 Wind Potential
3.1 Wind power generation √ x x
3.2 Wind water pumping √ x x
4.0 Mini/Micro hydro power X √ x
4.1 Electricity generation X x x
4.2 Motive power X x x
11
4.1 Makandi Estates
Two main areas for energy interventions are considered for Makandi. One of the areas is ener-
gy conservation it relates to improving efficiency of energy generation leading to potential car-
bon emission reduction and secondly we look at replacing the reliance on the diesel generators
with a potential option of replacing it with renewable energy options. As indicated in the table
above, at Makandi it was observed that there is potential for alternative energy sources that
include biomass, solar and wind.
Energy Efficiency Options
There are energy efficiency opportunities at the boilers (although further analysis is needed on
boiler efficiency). From experience potential savings of at least 10% can be made on boilers
which can lead to reduced firewood consumption of approx. 280m3/year. This will result in en-
ergy saving of approx. 887 MWhheat. The current equivalent carbon emission by the boilers is
estimated at 3940 tonnes of CO2. Thus the intervention will result in 394 tonnes of CO2 being
saved.
Renewable Energy Options
Wind power
Makandi shows very high potential for wind turbine to generate electricity. A picture of a tree
taken on site at Makandi shows that high wind speeds are available at sometimes and this in-
formation has been corroborated by the people who live in the area. There is no wind data
available on site and estimates provided by the RETScreen are available and have been used
for estimation of power generation as an additional option to unreliable ESCOM and reducing
the demand.
It is recommended to carry out detailed technical analysis of the wind speed and regime before
investing into a wind power plant.
Solar Power
Potential for both solar thermal and photovoltaic is high at the sites. The table below shows
satellite data from RETScreen and EU GIS Software showing the available solar radiation. The
feasible use of the solar would be for the purposes of preheating boiler feed water to save on
energy consumption and demand. 20% saving on biomass use for process heat is estimated.
This is equivalent to 560m3 of firewood leading to carbon saving of 400 tonnes of CO2.
4.2 Kawalazi Estates
Historically Kawalazi Estates has been identified with a potential for hydro power generation.
These assessments date back to 1979 when a feasibility study was undertaken to quantify the
potential for a hydro-electric development on the Lichelemu River. The report, which was kind-
ly provided by estate management, includes some basic information on hydrology, geology
and topography, but is quite basic owing to the equipment available at the time of writing and
it is likely that conditions have changed to some extent in the 32 years since the survey was
undertaken. The report does conclude that there is water available to generate up to 750kw,
1MW and 2.5MW from the river, so this is at least a preliminary indication that hydro power is
feasible at Lichelemu. Options for Kawalazi are basically energy efficiency and harnessing the
power of water to generate on site power for the estate and these are considered.
12
Energy Efficiency Options
There are energy efficiency opportunities at the boilers (although further analysis is needed on
boiler efficiency). Due to lack of technical information no further analysis is done although it is
recommended for next phase.
Kawalazi has also potential to disseminate improved firewood stoves for households. It is pro-
posed that a technology transfer arrangements where women within the estates could be
trained as entrepreneurs to produce the stoves by a women trainer group based in the same
district, at Chintheche. This is in line with enhancement of BIF goals of empowering the local
communities
Renewable Energy Options
There is high potential for hydro-electric power generation. Two sites were proposed by man-
agement but on the ground it was observed that only Lichelemu water system showed poten-
tial in terms of head and flow rates, and hence generation capacity. There are reports that
allude to potential mini hydro plant of 2MW to 3 MW capacity. The site at Kavuzi Weir has low
head and flow rates, and hence very low generation capacity. Thus, the Lichelemu water sys-
tem was taken further for a detailed feasibility study. The generation site could either be at
the break tank, which would demand additional transmission costs.
Our own assessment given the technical parameters at the site showed that with the current
infrastructure it is possible to generate 300 kW of hydro power at the site. The investment
would be about US$500,000 again we estimated this since most of the infrastructure exists.
The Power generation will be 600 MWh per year translating into a Carbon saving of approxi-
mately 200 tonnes per year. At a cost of US$10 per unit this would translate to US$2,000 per
annum of GHG equivalent. The saving of demand per year will be approx. US$100,000 per
year giving a payback period of roughly 5 years. But proper calculations will be required to
make a good estimation. Again if we can increase the power to 1 MEGA then we can potentially
gain much more and reduce the payback time..
4.3 Ngapani Estates
At Ngapani the main energy source for the operations is a diesel generator set. The general
workers currently have no access to modern energy and rely on traditional energy sources.
The lack of grid power at the estate and the unreliability of diesel in the country has con-
strained expansion plans at the Estate.
The diesel generator consumes 90,000 litres diesel per year. Thus the estimated energy
generation is 750MWh per year. This translates to a cost of US$135,000 per year of fuel. The
carbon emission is estimated at 3 MWh per tonne of carbon.
Solar Photovoltaic for Households
Communities at Ngapani particularly the junior members of staff in „villages‟ are without access
to modern energy sources for cooking and also for lighting, power for radio and TV. Sable
Farming is considering constructing a communal hall and using solar PV with entertainment
facilities at each of the village sites, as well as providing solar PV street lights. A simple solar
home systems and lanterns could be provided to households for use as lighting sources. For
13
cooking look into introduced fuelwood efficient stoves to address the cooking needs of the
communities.
Description of product Cost (MK) Approximate cost (US dollars)
1 Low cost kit : LED lamp, connectors for radio and phone (“Tough Stuff”)
7,349.00 42.00
2 5 lights + radio (50W panel) 175,750.00 1,005.00
3 5 lights +TV+radio (2x80W panels) 331,250.00 1,893.00
4 9 lights +TV+radio (2 x 80W panels) 371,450.00 2,123.00
5 12 lights +TV+radio (2 x 80W panels) 401,600.00 2,295.00
6 Street lights (per 5 lights)** 175,750.00 1005.00
Grid Extension
Currently, the Electricity Supply and Corporation of Malawi (ESCOM) is extending the grid to
Bakhresa Wheat Estates located about 15 km from Ngapani. Thus for medium term planning,
Sable Farming should gear consider to be linked to the electricity grid from Bakhresa since the
previous efforts to get connected through an alternative site that is about 12 km from the es-
tate passing through the Mizimu Forest was not accepted due to environmental reasons. The
cost of extending grid by ESCOM is in the range of US$12,000 per kilometre. This would
translate to around US$180,000 excluding contribution to the cost of transformers which is
about US$10,000 per transformer. Thus the total investment is estimated at US$250,000.
However the tariffs would have to be factored in at approx. US$70,000 per year. The saving on
diesel will be approximately 50%. This is equivalent to US$67,500 per annum. The emission
savings would be from diesel generator limited use that would translate to 122 tonnes of car-
bon savings per year.
14
5 Energy Proposals Table 5: Summary of Energy Proposal
Estate:
Makandi
Energy proposal measure No.:
1
Date:
15-03-2013
Energy proposal measure:
Improving efficiency of energy generation and use leading to
potential carbon emission reduction and secondly we look at
replacing the reliance on the diesel generators with a potential
option of replacing it with renewable energy options.
Page:
1 of 1
Present situation:
Biomass is a major energy source for boilers that produce process heat for the factory at
both Makandi. Unreliable power available from ESCOM affecting production at the Estate.
Energy proposal:
Improved boiler efficiency by introducing solar heating of boiler feed-water and other
energy saving measures that lead to reduced firewood consumption.
Look into the medium term plan to investigate the viability of the wind option as a
compliment to the power supply at the Estate.
Heat saving: The introduction of boiler heat efficiency will result in estimated saving of
20% of firewood.
- *
Wood savings = Annual Wood Cons (2800m3/year) * 20% saving = 560 m3/yr
-
Carbon emission savings 1 tonne of wood equivalent to 1 tonne of CO2 (wood density
is 0.71 tonnes/m3) Annual CO2 savings = 560m3/yr/(0.71tonnes/m3) = 789 tonnes
CO2
Cost of Savings
Annual Carbon Savings (789 tonnes/yr)* Cost per Unit of CO2 (US$10/tonne) = US$7,890
Power saving:
Introduction of alternative renewable energy system using wind power to reduce demand
and energy consumption. It is estimated that savings of 200kVA per month will be
attained.
15
Demand saving:
200 kVA/month*12 months = 2,400 kVA/year
Saving:
-
Demand component
2,4000 kVA/year * US$23/kVA = 55,200 US$/year
-
Investment:
The estimated investment is in solar water heating system and wind installation of 200kVA
and that will be app. 200,000 US$.
Payback period:
(200,000 US$)/(55,200+7,890 US$)/year = 3 years
Remarks:
-Investigate further potential on wind
Carry out detailed analysis of boiler efficiency and process heat utilization with a view to
saving firewood consumption.
16
Estate:
Kawalazi
Energy proposal measure No.:
2
Date:
15-03-2013
Energy proposal measure:
Energy efficiency opportunities at the boilers (although further
analysis is needed on boiler efficiency).
Installation of mini-hydro system (300kW)
Page:
1 of 1
Present situation:
There are energy efficiency opportunities at the boilers (although further analysis is
needed on boiler efficiency). Factory using a diesel backup generator and need to look
into alternative clean energy and also averting the serious diesel challenges which
disrupt production.
Saving proposal:
Energy efficiency measures are recommended for the boiler system to save on biomass.
The current levels of biomass utilisation are not yet established.
Introduce a mini-hydro power plant to provide own on-site power generation that is clean
and renewable.
Heat saving: To be further investigated
-
Power saving:
Utilise the existing irrigation infrastructure to build a mini-hydro power plant. Assessments
done on site indicate that with current infrastructure the power generation is limited to 300
kVA although potential for more can be investigated. On site power generation will result in
reduction of plat demand and also energy consumption overally.
Demand saving:
The annual demand savings = 300 kVA/month * 12months/yr = 3,600 kVA/year
Cost of demand savings = 3,600 kVA/year * US$23/kVA = 82,800 US$/year
Carbon saving:
The diesel generator at Ngapani has similar capacity to the proposed mini-hydro generator.
Based on the data from diesel consumption at Ngapani we assume that it will be the
equivalent diesel emission savings achieved by replacing that generator. The consumption
17
per year is 91,000 litres and the CO2 equivalent is 2.689 kg/l of diesel.
-
Saving:
91,000 litres/year * 2.689 kg/litre = 244,699 kg CO2/year
Cost of CO2 per annum
244,699 kg/year * US$10/tonne *0.001 tonnes/kg = US$2,447 CO2
Investment:
The investment will be in a mini hydro power plant mainly the power house, transmission
cables, generator, turbine and control equipment. The total investment is approx.
500,000 US$.
Payback period:
500,000 US$ / (2,447 + 82,800) US$/year = 6 years
Remarks:
-The data for boilers was not given and neither was the energy bill.
-Further detailed investigations recommended for the mini hydro and the efficiency
measures
18
Estate:
Ngapani
Energy saving measure No.:
3
Date:
15-03-2013
Energy proposal measure:
Seek alternative reliable power supply source for the estate to
reduce the diesel consumption. Improve access to modern energy
for the 620 households at the estate.
Page:
1 of 1
Present situation:
The estate is not connected to the national grid and currently uses a diesel generator for
the operations. Diesel is in short supply affecting the operations at the estate and limiting
the scope of activities. The workers are without modern forms of energy and have to rely
on traditional energy sources such as firewood. Approximately 620 households are on the
estate are affected.
Energy proposal:
An option considered is to connect the estate to the national grid to a place 15km away.
This is a medium term plan as the grid to that place is still under construction. In addition
it is proposed to provide the 620 households with improved firewood stoves and solar
home systems.
Heat saving:
-
Power saving:
Installation of grid to Ngapani estate which is 15 km. Due to excessive load shedding in
Malawi, it is anticipated that the estate will require 50% of the diesel fuel for backup
purposes.
Diesel saving:
75% of 91,000 litres/year = 68,250 litres/year
Cost of saving
68,250 litres/year * 1.50US$/litre = 102,375 US$/year
Carbon saving
68,250 litres/year * 2.689 kg CO2/litre = 183 tonnes CO2/year
Cost of carbon saving
183 tonnes/year * 10 US$/tonne = US$1,830/year
19
Cost of Maintenance Savings per year:
Annual Labour Costs for supervision of Genset + Annual Maintenance Costs
Salary US$200 /month *12 + US$2.500 /year =US$4.900/year
Total Savings from Diesel Generator = US$74.370 per year
Investment:
The investment in power line 15 km is set to be app. US$250,000 (made up of cost of
US$12,000/km, transformers and labour).
Estimated cost of energy bill from ESCOM:
Cost of energy demand:
200 kVA * US$23/kVA * 12 = US$55,200/year
Savings:
Cost of Energy Savings due to Power line = Cost of Diesel + Maintenance Costs – Cost of
Electricity Bill
US$109.105 – US$55.200 = US$53.905 per year
Payback period:
Total Investment/savings = US$250.000/US$53.905/year = 4.6 years.
Remarks:
-The investment in the power line will make economic sense provided the supply
security from ESCOM is guaranteed at least 75% of the time.
-When other economic benefits are factored the option will become much more
profitable.
20
6 Recommendations
The assessment found reasonable energy intervention options in all but one estate Ngapani, it
is thus recommended to carry out detailed feasibility studies on Makandi and Kawalazi Estates.
The exercise should help to collect further information to allow for detailed and specific investi-
gations in the identified areas of intervention. At Makandi it is recommended to carry out ener-
gy efficiency interventions and analyze the potential of the wind. At Kawalazi, it is recom-
mended to carry out detailed technical studies for the installation of the mini-hydro. At Nga-
pani, grid extension while being the feasible option the cost benefit indicates that it will be
negative unless other economic factors are considered such as improved production and wel-
fare.
7 Conclusion
There are feasible renewable energy options at Makandi and Kawalazi Estates. Potential energy
efficiency options are also identified for the process heat at the two factories. At Ngapani, it
the most feasible option was grid extension to the estate. We conclude therefore that detailed
studies with a view to implementing the proposed measures be undertaken at Makandi and
Kawalazi Estates.
21
8 REFERENCES
1. Action Aid (2006).Climate change and smallholder farmers in Malawi: Understanding
poor people‟s experiences in climate change adaptation, Johannesburg, South Africa.
2. Banks D I and Gondwe K J (2006). Barrier Removal to Renewable Energy in Malawi,
Mid-term review, UNDP.
3. BERL (2009). Fueling a Greener Future, http://www.berl.biz
4. Catherine M. O‟Reilly, Simone R. Alin, Pierre-Denis Plisnier, Andrew S. Cohen & Brent A.
McKee (2003).Climate change decreases aquatic ecosystem productivity of Lake Tan-
ganyika, Africa, Department of Geosciences, University of Arizona, USA.
5. Department of Climate Change and Meteorological Services (2010). Climate of Malawi,
http://www.metmalawi.com/climate.
6. Fernandez-Ares, A and Abdirizack A (2005). Kenya Tea Development Agency Small
Hydropower Development.
7. Gondwe, K J, “ Status and Stage of Dissemination of Biomass Energy Utilisation in Ma-
lawi”, DANIDA Alternative Energy Studies I n Malawi Phase I, April 1998.
8. Government of Canada (2004): Micro Hydropower Systems: Buyer‟s Guide, ISBN-
0662-35880-5.
9. Government of Malawi (2003a). Malawi‟s Climate Technology Transfer and Needs As-
sessment, Report to UNFCCC, Environmental Affairs Department.
10. Government of Malawi (2003b). Malawi Energy Policy, Department of Energy Affairs.
11. Government of Malawi (2006). Promotion of Alternative Energy Sources Project, Pro-
ject Document, Department of Energy Affairs.
12. Government of Malawi (2011). Malawi Growth and Development Strategy II, Ministry
of Economic Planning.
13. Malinski B (2008).Impact Assessment of Chitetezo Mbaula : Improved Household Fire-
wood Stove in Rural Malawi, ProBEC/ GTZ.
14. Werner U et al (1989). Biogas plants in animal husbandry: a practical guide, GATE/GTZ,
ISBN 3-528-02048-2.
15. World Bank, “Millennium Gel fuel: A Renewable and Low Cost Cooking Fuel for Africa,”
Regional Programme for Traditional Energy Sector (RPTES).
22
9 Annex I: Estimating Potential HEP generated at Lichere-
mu water system
Table 6: Potential HEP generated at Licheremu water system
S/N
PARAMETERS UNITS Site 1 (Main
manifold)
Site 2
(break
tank)
A Altitude at intake m 780.8 917.8
B Altitude at outlet m 644.9 780.8
C Head, H= A-B m 135.9 137.0
D Free fall velocity at manifold, v=(2gH)½ m/s 51.64 51.84
E Volumetric flow rate= v x area m3/s 8.21 8.24
F Ideal(max) power generated Pmax=QHg kW 10,949 1129
G Available power, Pa= e x Pmax kW 3,285 3387
Pw = Q x H x g x e
Q = Flow rate in m3/s
H = Head in m
g = Constant due to gravity in m/ s2 (9.81 m/s2)
e = overall efficiency ration
e = accounts for losses in pipes x penstock x turbine x generator x transmission
is approximately 0.3 to 0.5 for a typical penstock length. For this assessment,
the value of 0.3 has been used due to frictional losses in the 9+km pipe length. Typical values
are shown below.
Ecivil work : 1.0 - (Channel length × 0.002 ～ 0.005)/ Hgross
Epenstock : 0.90 ～ 0.95 (it‟s depends on length)
Eturbine : 0.70 ～ 0.85 (it‟s depends on the type of turbine)
Egenerator : 0.80 ～ 0.95 (it‟s depends on the capacity of generator)
Edrive system : 0.97
Eline : 0.90 ～ 0.98 (it‟s depends on the transmission length)
Etransformer : 0.98
Source: JICA (2009). Manuals and Guidelines for Micro-hydropower Development in Rural Elec-
trification Volume I
23
10 Annex II: Renewable energy options for Malawi
10.1.1 Biomass based fuels and end-use technologies
Biomass energy has been associated with health hazards resulting from indoor air pollution,
low efficiency of end-use devices such as the 3-stone stoves, deforestation and land
degradation. Despite these challenges, biomass has remained the dominant fuel in not only in
Malawi but the region as a whole accounting for over 85% of energy supply. In the rural
areas, biomass is often collected free but current trends show that women walk longer
distances in search of firewood; where it is sold it is packaged in small affordable lots. A few
communities and households have their own woodlots. In addition to wood, crop residues and
other biomass wastes such as saw dust may be used directly or compressed into briquettes
through the process of densification. Briquetting technology has been in existence for a long
time.
Figure 2 a: Traditional 3-stone cook place
Figure 2b: Improved firewood stove
24
While PAESP goal is noble, it may not be possible to substitute biomass in short to medium
term. With the prevalent poverty situation in the country, biomass is likely to remain a
principal energy for the rural population in Malawi for many years to come. People need to
improve in their economic conditions to be able to move the energy ladder. The more urgent
challenge to the practitioners is to find better ways of using biomass more efficiently and
sustainably resulting in less harm to the users‟ health and the environment. People can also
improve their health and productivity as they move up the energy ladder.
There are a number of institutions that have been addressing the challenges related to low
efficiency and indoor air pollution. Ceramic stove “mbaula” based on Kenyan “jiko” were
disseminated by the Blantyre Fuelwood Project within the Department of Forestry and the then
Mulanje-based GTZ Programme on Biomass Energy Conservation (ProBEC) which has
promoted a number of improved technologies such as clay wood stoves, HH rocket stoves and
institutional rocket stoves. ProBEC has implemented its programme in all the three regions of
Malawi while operating from their Mulanje Office. With the phasing out of ProBEC, the
activities are now handled by Mulanje Renewable Energy Agency (MuREA) in collaboration with
Mount Mulanje Conservation Trust (MMCT).
Wastes can also be used to produce biogas. Biogas technology is a modern, ecology-oriented
form of technology based on bio-degradation of organic materials (such as animal dung and
other bio-waste) in anaerobic condition by putrefactive bacteria at suitable, stable
temperatures. It is odourless, colourless and combustible gas consisting of a mixture of mainly
methane (CH4), carbon dioxide (CO2) and other minor gases, which include hydrogen (H2) and
hydrogen sulphide (HS) among others, leaving behind digested slurry which is very reach
organic fertiliser. Despite the fact that biogas was introduced in Malawi in the late 80s, the
technology has not really picked up. Some of the barriers are high initial investment cost,
culturally dung is associated with dirt, limited technical skills and poor animal husbandry
practice (animal are grazed on free range hence difficult to collect manure). The lead
institutions are Magomero Vocational Centre and Malawi Industrial Research and Technology
Development Centre (MIRTDC).
Figure 3: Biogas technology integrated in the farming system Source: Werner U et al (1989).
25
10.1.2 Bio fuels
Malawi has been producing ethanol that is used for blending with petrol for many years. It is
reported that countries like India do use ethanol as a fuel for both cooking and lighting
purposed. Potentially, ethanol could be extended to be using for household applications. It is
not only renewable but also locally produced and is available at industrial level. Department of
Energy and Ethanol Company have been experimenting on a household stove produced in
South Africa since 2006. The technology requires more field trials before it could be
disseminated at a wider scale. Even if the trials turn out to be a success, more work will be
necessary to get the product distribution network in place. Furthermore, there will be need for
an aggressive public awareness and user training.
Malawi also experimented on gel fuel which was being imported from Zimbabwe and South
Africa. The product was launched and was available in the market for some time.
Unfortunately, the business proved not to be financially viable as it was competing with
paraffin whose prices are often subsidized. Another product that is being tried is Blue Wave.
This is yet to be field tried a wider scale and be launched. Zimbabwe has succeeded in
growing of Jatropha curcas using small scale farmers for the production of bio-diesel. Locally,
some growing trials have been going on for a few years championed by Bio-Energy Resources
Limited (BERL) and smallholder farmers in a number of districts. The Faculty of Science at
Chancellor College has also been experimenting on bio-fuels for some time. Despite the
advantages that bio-fuels could be sourced locally, and be source of livelihood for Malawians
and are less harmful to the environment, there are other technological challenges before it
could be used as a household fuel. In addition, there is a global debate claiming that bio-fuels
would compromise food production.
Figure 4: Jatropha curcas ripe fruits
Source : Henning R., Jatropha curcas in Africa – an Evaluation
10.1.3 Solar Energy
The whole continent of Africa may generally be considered as a high potential area for solar.
According to reports many countries receive an average of 325 days of per year of bright sun-
light (Yansane, 2007). Despite the high potential, Africa has not made meaning effort to ex-
ploit the massive resource due to various constraints. Most of the applications have been
small stand alone home systems. The only facility that has been linked to the grid is the Kiga-
26
li-based 0.25MW power in Rwanda that was supported by the German Government through
GTZ. Large scale applications are under development in South Africa and Algeria (Nji, 2006).
Being within the tropics, Malawi has high solar power potential with an average of 3000 hours
of sunshine per year falling at a rate of 2200 kilowatt hours (kWh) per square metre. Tradi-
tionally, direct solar power has been used as a source of energy for drying clothes and crops
for a long time, a practice that is common to this very day. In the 80‟s, the Government pro-
moted the use of solar thermal systems for water heating in public facilities such as hospitals.
In terms of large scale promotion and comprehensive boost came in late 1990‟s with the Glob-
al Energy facility (GEF)/ DANIDA funded programme of Barrier Removal to Renewable Energy
in Malawi Project (BARREM) within the National Sustainable and Renewable Energy Programme
(NSREP). Under BARREM, assessments were undertaken, human and institutional capacity
built, policy incentive put in place (duty waiver on all RETs) and a number of demonstration
facilities were developed to popularize the solar PV technologies. Currently, solar technology is
considered as the technology of choice to supply electricity to rural public facilities that are
sited far from the national grid. In the recent past, the Government has electrified five demon-
stration villages (in Mzimba, Nkhata-Bay, Nkhota-Kota, Ntcheu and Thyolo) where more than
150 households at each site have been electrified using solar PV/wind hybrid systems. Each
site has an installed capacity of 25kW. Work on the sixth village is not yet complete.
Figure 5: Map of Africa showing solar irradiation
Source: NREL, UNEP, GEF
27
Figure 6: Solar PV application in a rural hospital, Mzimba in the Northern Region of Malawi.
Photo by KJ Gondwe,2007.
10.1.4 Wind Energy
Wind is moving air, and as such contains energy due to motion of the air mass (kinetic
energy). This energy can be harnessed using appropriate devices to recover useful mechanical
power that could be used to pump water or generate electricity. Wind data has been taken by
Meteorological Department and other institutions for some time at 2m height which is not very
useful for design of wind technologies. The assessments show that wind speeds in Malawi vary
from 1 to 7 m/s. Highest monthly mean wind speeds occur between May and November. A lot
of data on the wind characteristics is required to ensure the appropriate device is selected. For
electricity generation, wind speeds above 3 m/s are recommended while for water pumping
lower speeds are still acceptable. There are recent designs of wind turbines for electricity
generation that can operate with much less stringent cut off speeds.
There are a few sites in Malawi where wind water pumping devices are used and even fewer
sites where solar-wind hybrid systems have been installed for electricity generation. The
Government of Malawi has recently commissioned five demonstration villages where 150
households have been electrified using decentralised mini-grids using solar/wind hybrid
system.
28
Figure 7: Wind/solar hybrid system application
According to the report by the Deapartment of Energy (2010), some of the potential sites for
installing the large capacity wind turbines include;
i. Lulwe Mission Area
ii. Thyolo Mountain
iii. Mulanje Mountain
iv. Ndirande Hill
v. Soche Hill
vi. Chilomoni Hill
vii. Nkopola Hills
viii. Cape Maclear – Monkey bay Hills
ix. Mvera Hills
x. Viphya Plateau
xi. Nyika Plateau
xii. Dzalanyama Range
Thus, the sites at Makandi fall within the Thyolo Mountains.
10.1.5 Hydropower
A mass of water moving down a height difference contains potential energy. As the moving
water move down the gradient it will lose potential energy and gain kinetic energy. This can
be kinetic energy can be harnessed by causing to drive a waterwheel or turbine, which in turn
can directly move a pump or mill, or alternatively it could be coupled to a generator to produce
electricity. Unlike wind or solar energy which often require storage equipment such as battery
bank, hydro power is continual available as long as there is adequate water flow rate.
29
Figure 7: Small/Large scale HEP sites by ESCOM
The Japanese technical experts (JICA) and counterparts from the Department of Energy
undertook a comprehensive assessment of micro/mini hydro potential in Malawi. A number
sites have been identified.
Energy Demand at Household level
In order to determine the energy requirements, it is necessary to know the power of the end-
use device in terms of wattage such as number of electric bulbs and the duration they are on.
Demand (KWhr) = Wattage × hours
1000
It is necessary to consider the energy demand at the design stage so that the energy supply
system is correctly loaded. Both overloading or under-loading the system is costly to the
investors. Furthermore, it is important to know what time of the day the energy will be
required. This will help to determine energy demand peaks and troughs so that appropriate
energy management interventions could be put in place.
The assessment of energy demand for a household would involve the following steps:
List all the electrical appliances in the home;
Check the power ratings of the appliances provided on the back label;
Record or estimate the number hours per day the appliance is in use;
For each appliance the loaded is obtained by multiplying watts by hours
Add the watt-hours of each appliance to get the total load.
The table below shows typical electric end use devices and average ratings based on averages.
30
Table 7: Estimated energy demand for Senior Staff/Management
Appliances Power rating (W) Numbers Watts Average hours
per day
Energy used
per month
watt-hour
Lights In candescent -60W 60 6 360 14 5040
Lights In candescent -100W 100 2 200 12 2400
Portable electric cooker 1000 1 1000 3 3000
Portable electric fan 120 1 120 1 120
Radio/Stereo 100 1 100 8 800
Colour television 100 1 100 4 400
DVD Player 15 1 15 2 30
Computer-PC 250 1 250 2 500
Computer-Laptop 65 1 65 4 260
Refrigerator 500 1 500 24 12000
2710 TOTALS 24550
If energy saver bulbs are used check ratings Table 8: Junior Staff Houses
Lights In candescent -60W 60 4 240 3 720
Lights In candescent -100W 100 1 100 12 1200
Radio/Stereo 100 1 100 6 600
Television 100 1 100 4 400
540 TOTALS 2920
Wind assessment
There are two main types of wind turbines which are classified based on the position of the
axis of the rotor. The two main types are Horizontal Axis Wind Turbine (HAWT) and Vertical
Axis Wind Turbine (VAWT).
VAWT is designed with a vertical rotor shaft, and then a generator and gear box are positioned
at the bottom of the turbine. The uniquely shaped rotor blades are designed to harness power
from wind irrespective of direction of the wind.
31
Figure 8: Horizontal Axis wind turbine (HAWT) Figure 9: Vertical axis wind turbine (VAWT)
As implied by the name, the HAWT shaft is mounted horizontally, parallel to the ground.
HAWTs need to constantly align themselves with the wind using a yaw-adjustment mechanism.
The yaw system typically consists of electric motors and gearboxes that move the entire rotor
left or right in small increments. The turbine's electronic controller reads the position of a wind
vane device (either mechanical or electronic) and adjusts the position of the rotor to capture
the most wind energy available. HAWTs use a tower to lift the turbine components to an opti-
mum elevation for wind speed (and so the blades can clear the ground) and take up very little
ground space since almost all of the components are up to 80 metres in the air.
Large HAWT components:
rotor blades - capture wind's energy and convert it to rotational energy of shaft
shaft - transfers rotational energy into generator
nacelle - casing that holds the gearbox (increases speed of shaft between rotor hub and
generator), generator {uses rotational energy of shaft to generate electricity using elec-
tromagnetism), electronic control unit (monitors system, shuts down turbine in case of
malfunction and controls yaw mechanism), yaw controller (moves rotor to align with di-
rection of wind) and brakes (stop rotation of shaft in case of power overload or system
failure).
tower - supports rotor and nacelle and lifts entire setup to higher elevation where
blades can safely clear the ground
electrical equipment - carries electricity from generator down through tower and con-
trols many safety elements of turbine
Typical data required for wind power planning:
Average wind speed (monthly, annually)
Wind distribution
Average wind energy density
Estimated wind power production
Maximum wind speed at the hub height;
Intensity of turbulence.
32
Wind shear
Extreme wind gradient
Others: Special weather conditions or extreme weather events.
The diagram below shows how the wind turbine ought to be installed to ensure that they
operate efficiently
Figure 10: Orientation and spacing of wind turbines The turbines need to be mounted properly with respect to the direction of prevailing winds; it is also necessary to maintain the recommended distances between turbines. Ideal power generate from the wind is given by
Pw = Cp × p × A × V3
Cp : Power coefficient p : density of the oncoming air A : swept area of the blades V : velocity of the wind
33
Table 9: Cost structure of wind turbine
Figure 11: Cost/kWh for different wind
regimes
Hydroelectric power (HEP)
The main components of small hydro electric power system are:
A. Intake/weir: It is used to divert stream flow from the water course;
B. Canal/ pipeline: It is used to carry water from the intake to forebay tank;
C. Forebay tank: It is used to settle and/or filter debris and prevents it from being drawn
and carried into the penstock to the turbine;
D. Penstock pipe: It carries the water to the power house
E. Powerhouse: It is where the turbine and the generator are housed to convert the
kinetic energy of the water into electrical energy;
F. Tailrace: It is the waterway through which the water is released back to the river
G. Transmission line: It carries the generated electricity for distribution to where the loads,
normally through transformers and other electrical gears.
Figure 12: Mini/micro hydropower system
Source: Government of Canada (2004): Micro Hydropower Systems: Buyer’s Guide.
Basic reference materials or documentation required during assessments and planning phase
for small hydro power project includes:
Topographical map
34
o Gradient: Ideally high head, shortest waterway and high flow rates;
Topographical information can help reduce civil costs;
Catchment area: should be large enough, well managed and protected to ensure
sustainability;
Rainfall data or rainfall maps collected over a long time will help give historical
perspective and consistency of the climate;
Determination of the river flow rate;
Despite seasonal variability, potential site must meet minimum flow rates required;
Geological conditions
o Quaternary volcanic rock High water retention capability;
o Rivers with limestone show irregular discharges;
Undertake water balances-link between rainfall, evaporation and run off.
The power equation for HEP is given by
Pw = Q x H x g x e
Q = Flow rate in m3/s
H = Head in m
g = Constant due to gravity in m/ s2
e = overall efficiency ration
e = accounts for losses in pipes x penstock x turbine x generator x transmission
Table 10: Various types of HEP turbines for different heads
Turbine runner High Head
(more than
100m)
Medium Head
(20 to 100m)
Low Head
(5 to 20m)
Ultra Low
Head
(less than 5m)
Impulse Pelton
Turgo
Cross-flow
Turgo
Multi-jet Pelton
Cross-flow
Turgo
Multi-jet Pelton
Water wheel
Reaction - Francis
Pump-as-turbine
Propeller
Kaplan
Propeller
Kaplan
Source: Government of Canada (2004): Micro Hydropower Systems: Buyer’s Guide.
