Hans Petter Bjornavold_Implementation of a Microhydro Power Scheme_2009_REPORT

8/9/2019 Hans Petter Bjornavold_Implementation of a Microhydro Power Scheme_2009_REPORT

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School of Engineering, University of

E

A Feasibility S

Micro-Hy

Warwick

S327 Project Report

tudy on the Implementa

ro Scheme in Sioma, Za

0602641

ion of a

bia


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School of Engineering, University of Warwick 0602641

Author’s Self Assessment

The following project report details the micro-hydropower concept, principles and finally its

application to the case of Sioma, Zambia. In order to achieve this, both primary and

secondary data has been collected and analysed. The analysis of this data has led to

decisions involving the design, and improvements to it, as well as the selection of location. It

is the author’s intention that the Sioma micro-hydro project will be developed into a pilot

scheme for developing communities and consequentially will form the basis of future

engineering contribution. If the ancient techniques of micro-hydro schemes are reworked

and improved, important improvements within the engineering field are implicit and

infrastructure development is continuously emphasized.


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Summary

In light of this project, the application of micro-hydropower appears ideal for rural

communities, particularly in the developing world. The provision of electricity is a vital step

in developing infrastructure which, in turn, entails vast improvement to quality of life,

competitiveness of local businesses and learning opportunities. The first section of the

project consists of a literature review on the micro-hydro area, which is subsequently used

for analysis and application to the Sioma site, found in Section III, titled “Feasibility Study”.

The Sioma Falls were determined to be the most viable location for a potential site, with a

head of approx. 10 metres. The flow of water in the Zambezi is adequately high year round

so that the theoretical limit of power production does not limit the proposed project. A

flow of 0.587 m3/s in the penstock is necessary to develop the 46.1 kW of power that was


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Table of Contents

Author’s Self Assessment...........................................................................................................2

Summary ....................................................................................................................................3

List of Tables and Illustrations ...................................................................................................6

Section I - General......................................................................................................................7

1.1 Introduction.................................................................................................................7

1.2 Final Project Specification ...........................................................................................8

1.3 Research Methodology ....................................................................................................9

Section II - Literature Review...................................................................................................10

2.1 Hydropower Generation: ...............................................................................................10

2.2 Micro-Hydro and Rural Development............................................................................12

2.3 Technical aspects............................................................................................................13

2.4 Turbines..........................................................................................................................15

2.5 Coupling..........................................................................................................................19

2.6 Generators and Control .................................................................................................21

2 7 Ci il k 23


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3.3 The potential contribution to the local community.......................................................56

3.4 Financial viability............................................................................................................593.5 Ownership ......................................................................................................................61

3.6 Meeting with ZEEC .........................................................................................................63

Section IV – Conclusions and Recommendations....................................................................64

4.1 Conclusions.....................................................................................................................64

4.2 Costing of Project ...........................................................................................................654.3 Recommendations .........................................................................................................66

Glossary of Definitions .............................................................................................................67

References/Bibliography..........................................................................................................68

Appendix A...............................................................................................................................70

Appendix B ...............................................................................................................................71

Appendix C ...............................................................................................................................72

Appendix D...............................................................................................................................73

Appendix E ...............................................................................................................................74

Appendix F ...............................................................................................................................75

Appendix G...............................................................................................................................76

Appendix H...............................................................................................................................77

Appendix I ................................................................................................................................81

Appendix J ................................................................................................................................85

A di K 86


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List of Tables and Illustrations

Figure 1- Worldwide technical hydropower potential versus economically feasible and present

situation

Figure 2 – Run of the river micro-hydro scheme typical layout

Figure 3 – Turbine Classification Chart

Figure 4 – Turbine Selection Chart

Figure 5 - Francis Turbine

Figure 6 - Tube type propeller turbine

Figure 7 – Pelton Wheel

Figure 8 – Turgo Turbine

Figure 9 – Crossflow Turbine

Figure 10 – Diagram of incorporation of Electronic Load Controller into generating system

Figure 11 – Dam used to create water reserve for micro-hydro scheme

Figure 11 – Sioma Falls

Figure 12 – Intake and weir at Tungu-Kabri project


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Section I - General

1.1 Introduction

Many rural communities in developing countries suffer the same symptoms; a never-ending

cycle of poverty and lack of basic necessities. For many decades large aid organisations have

focused on emergency relief without assessing the causes; simply fire fighting incessant

difficulties. It is the author’s belief that rural infrastructure development is a solution to

these underpinning problems, and that, with the development of roads, safe water supplies

and electricity, communities can overcome the barriers to living long, safe and healthy lives.

Sioma, in South Western Zambia, is such a community. Its population is approximately 1500

of which about 50% HIV positive. Despite a main power cable passing just a few kilometres


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1.2 Final Project Specification

The project specifications at the point of starting in October 2008 included the following

objectives:

Research possibility and prove viability of hydroelectric scheme in Sioma, Zambia

Produce a proposal for such a scheme

Network with engineering charities for support

Put plan into action (outside academic boundaries)

These were realistic objectives that were achieved to different degrees. The project initially

t t d ith lit t i h l t i f th i h d fi ld


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Additional completed objectives are:

Apply for letter of support from local government

Complete initial technical analysis, calculations and design

1.3 Research Methodology

The following project has been approached primarily by literature research. Focusing firstly

on gaining a wide and comprehensive understanding of the chosen subject area, a literature

review was completed. The literature review included the reading of a range of textbooks

along with credible internet sources and journals. Relevant aspects of these sources were

th d t f l t t hi h th d i th i l t ti f th t


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Section II - Literature Review

The literature review is a comprehensive summary of the material covered through the

project research. It should give a good insight into the development of micro-hydro sites

in general and provide a sufficient foundation for the following analysis in the feasibility

study.

2.1 Hydropower Generation:

Close to a quarter of the energy of the sun that reaches the earth’s surface causes water to

evaporate and hence a proportion of this energy causes vapour to rise against the earth’s

gravitational pull. This vapour then condenses into rain and snow, which again falls back to

h h’ f Thi i ll d h l d i h f d l h


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Figure 1- Worldwide technical hydropower potential versus economically feasible and present situation [4]

The potential for hydropower expansion is still enormous; the U.S Geological Survey

estimates that 2/3 of the world’s hydropower resources remain untapped. [5] The main

advantages of investing into further hydropower development are summarized below:

N f l b i i i l ll i


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2.2 Micro-Hydro and Rural Development

Access to electricity is one of the key recipes for rural development and a necessity for the

improvement of infrastructure. An estimated 1.5 billion people in developing countries do

not have access to electricity [6], severely limiting the possibilities of economic growth. An

increased focus on decentralized energy generation, where the state cannot viably connect

population centres to the main electricity grid, significantly improves the development

prospects of struggling communities. Micro-hydro provides a reliable, affordable,

economically viable, socially acceptable and environmentally sound energy alternative for

rural development.

Micro-hydro is the small scale harnessing of energy from falling water, generating typically

less than 100 KW [7] and powering small communities or factories. It is micro-hydro the


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2.3 Technical aspects

A brief technical review of

technology numerous textbo

Micro-hydro schemes gener

scheme where no water stor

into a canal before being “dr

Warwick

ydropower is provided below. Due to t

ks are available with more detailed technic

lly follow the layout shown in Figure 2 –

ge is required. Instead water is deflected f

pped” from the forebay tank to the turbine.

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e maturity of the

l analysis.

a run of the river

rom a flowing river


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Where PE = potential energy

(9.81m/s2) and Hav = availabl

(ii) The power availa

product of the ava

Where P = Power (W), η = eff

due to gravity (9.81m/s2), Q =

Warwick

(Joules), m = mass of water (kg), g = acceler

head (m).

le at a hydropower station will always be

ilable head and the volume flow rate of the

iciency of system, ρ = density of water (kg/m

volumetric flow rate (m3/s) and Hav = availa

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tion due to gravity

roportional to the

site:

3), g = acceleration

ble head (m)


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Figure 4 – Turbine Selection Chart [10]

Reaction Turbines

Reaction turbines run with a casing completely filled with water, exploiting the oncoming


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The Francis turbine is, in effe

water is made to enter the tu

reaction turbines are more c

and case profiling. This mak

their superior performance a

Impulse Turbines

Impulse turbines are the mor

jet strikes directly on the tur

rotational motion (and henc

energy.

The most common impulse

Warwick

ct, a more complicated version of the prop

rbine radially and discharge axially. In term

hallenging to fabricate due to the use of m

es them less attractive for micro-hydro use

low-head sites, they are nonetheless increa

e traditional alternative of turbines, where

ine blade or bucket surfaces. This pressuri

e mechanical energy) which can be conve

turbine is the Pelton wheel (figure 7), whi

0602641

ller turbine where

of manufacturing,

ore intricate blade

. However, due to

singly popular. [9]

pressurized water

ed jet then caused

rted into electrical

ch is fitted with a


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The Turgo turbine (figure 8) i

strikes the runner at an angle

not limited by discharge buil

have a smaller diameter turbi

Image source: “Small hy

The Crossflow turbine (fig

ff

Warwick

s simply a more advanced version of the Pel

to aid discharge. This ensures that the rota

up and interference. This also means that

ne than a Pelton for the same power output

Figure 8 – Turgo Turbine

dro power: technology and current status”, Oliver Paish, Elsevier S

ure 9) is similar to the Pelton and T

f

0602641

ton. The water jet

ion of the wheel is

Turgo turbines can

.

cience Ltd, 2002

rgo turbines but

f


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2.5 Coupling

Coupling between the turbine and the generator (or other machinery) is a vital part of any

micro-hydro system. In the optimal case the turbine and generator are selected to rotate at

the same speed. If this is achieved, then the need for gearing is eliminated and hence the

amount of parts that may need maintenance/replacing are minimised. This is the case with

all large scale hydropower schemes, where careful design of each turbine is necessary.

However, in many micro-hydro schemes cost may limit this optimisation. So there are two

main streams of coupling for micro-hydro schemes:

Direct Coupling

As stated earlier, this is achievable when the turbine and generator operate at the same

speed and the set up can be laid out so that their shafts are co-linear. [11] This means that


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Belts are more elastic than chain drives or gears and so one of their main advantages is that

they can absorb shock by sudden changes in loads or other factors well. In addition, if one

component should lock up, slippage of flat belts will prevent damage to the more expensive

equipment. [11]


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2.6 Generators and Control

Generators transform the mechanical energy produced by the water hitting the turbine into

electrical energy. Early hydroelectric systems made use of Direct Current generation to

match the requirements of early electrical equipment; however, modern schemes make

almost exclusive use of three phase alternating current generators. [10] There are two main

groups of generators:

Synchronous Generators:

Excitation with synchronous generators is not grid dependent and so can run in isolated

locations. The generator operates at a speed directly linked to frequency when not

connected to the grid, but speed variation is not possible when it is connected to a grid. In

the case of off-grid use, the voltage controller maintains a predefined constant voltage


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overloading or over-speeding. Electronic Load Controllers (ELCs) have been developed over

the past two decades to provide reliable regulation of output power in a micro-hydro

system. They control the amount of load by automatically varying the amount of power

dissipated in a resistive load, often known as the dump load. This keeps the load on the

generator and turbine constant by constantly sensing and controlling the generated

frequency. [12]

ELCs contain no moving parts, and are therefore virtually maintenance free. They also

eliminate the need for expensive hydraulics governors.


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2.7 Civil works

The main civil works required for a complete micro-hydro scheme are demonstrated by

Figure 2, shown in the general hydropower discussion. In addition various other

components may be required, such as spillways, gates etc. However, a designer must be

very careful when planning a scheme not to include unnecessary components leading to

excessive and avoidable costs. It must, nonetheless, be ensured that all necessary

components are included in the design to avoid the malfunctioning of the scheme. Below is

an overview of the main components and their uses in micro-hydro schemes:

Dam

In most large scale hydropower developments dams are thought of as inherent aspects of

construction. A dam’s function is to either increase available head (for example when


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Figure 11 – Dam used to create water reserve for micro-hydro scheme [27]

Diverting Flow

In order to ensure adequate flow to the intake for power generation, a weir may be


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Intake

The intake is the link between the river and the conduit to the powerhouse. Its role is vital

in the overall functioning and reliability of the scheme. It is used to control both the quality

and the quantity of water and must be equipped to deal with extremes in terms of water

flow.

In order to prevent debris and sediment carried by the incoming water several objects can

be incorporated with the intake, such as trashracks, skimmers or a settling basin.

Water flow control under all conditions is also a necessity. Gates can be used to perform

this task, along with spillways as backups to release overflow back into the stream. If the

water flow is not controlled at the intake, the power conduit may overflow at unexpected

points causing severe erosion and damaging the scheme.


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work will be required at the site. The location along the stream determines the amount of

sediment and trash accumulation an intake will see as well as the erosion it will suffer.

When locating the intake there are four key factors to be considered:

The streambed

Bends along the stream

Natural features of the stream

Ease of access

The susceptibility of the streambed to erosion is a key factor when determining the

elevation of the canal intake. Normally this is done at the time of construction, and hence,

it is important to bear the nature of the streambed in mind throughout this process. If the

streambed is particularly susceptible to erosion the intake may eventually reach a point


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Natural features of the stream can be used to our advantage wherever possible. Features

such as large boulders have been used in the past to effectively restrict flood flows. Natural

features can also limit the need for construction, and so, when on site, it is advantageous to

analyze all potential sites for construction.

Ease of access is essential in all stages of the scheme. During construction, supplies need to

be transported easily along the site. During heavy flows it is particularly important to have

safe and easy access since this is when repairs are most likely to be needed. Trashracks and

debris must be clearable at all times.

Power Conduit

The power conduit’s purpose is to transport water from the intake to the penstock inlet

with minimum head loss at a minimum cost. In most cases this means that a canal will be


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Figure 13 – Power conduit in Tungu-Kabri project [28]

Forebay

The Forebay tank is the connection between the power conduit and the penstock, serving

mainly to allow particles to settle down before the water enters the penstock. It can also be

used as storage for water in the case of increased power consumption at peak times of the

day, for example. A trashrack is normally installed at the penstock inlet to prevent floating


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Figure 14 - Penstock at Bamerchara Lake, Bangladesh [29]

Powerhouse

The powerhouse is meant to protect the turbine, generator and other electrical and

mechanical equipment. In the case of micro-hydro, it should be kept to a minimum size in

order to minimise costs. However, sufficient space must be kept to allow for repairs and


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2.8 Other micro hydro schemes in Zambia

NWZDT - Zambezi Rapids Hydro-Electric Scheme [13]

The Zambezi Rapids Hydro-Electric Scheme was completed in July 2007 after three years of

work in the North Western Province of Zambia. This was achieved by NWZDT (North West

Zambian Development Trust), a charity set up by a group of people connected to the area

and the Kalene Mission Hospital. The charity’s philosophy is that while many individual

crises can be solved by food and medicine, real progress comes through the development of

infrastructure.

A sustainable electricity source was seen as a priority to trigger the other aspects of

infrastructure, and so the scheme was completed. It is a 700 KW run of the river set up,

with 99% of work done by local, unskilled labour. It powers a great number of local


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Zambia and served to demonstrate the viability of small hydro projects in small

communities. A 2.5 KW generator was installed, generating enough power for lighting the

community but not much else.

Currently there is demand to expand the scheme to give 200 KW of power, but there is a

lack of funding to achieve this. The project cost USD 30,000 in total which was raised by a

German church organisation (EZE), and a fee of USD 1.05 is charged monthly to all

households, covering repair and maintenance costs.


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2.9 Local manufacture and labour

In order to maximize the chances of success when implementing a micro-hydro scheme it is

extremely important to involve the local community from day one. If this is done the

community will take pride in their project and work to maintain it operational. This

community involvement means that local manufacture and labour will be used – giving the

workers an insight and understanding into the functioning of the scheme and hence they

will be able to maintain the plant without excessive external assistance.

In addition the use of local manufacture and labour will significantly decrease costs in many

areas. This does require flexible design of sensitive parts, such as the turbine, to allow for

inaccuracies during manufacture. Efficient designs can, nonetheless, be achieved – as we

can see in Las Juntas, Peru, where the L-1 turbine achieved up to 89% efficiency [15].


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2.10 Cost Reduction

When planning a micro-hydro scheme it is important to ensure that the idea is financially

viable. If it is not, it will be difficult to maintain the scheme even after the initial costs are

covered. This is why income-generating uses of the power must be considered before

deciding whether the scheme is viable.

The majority of costs will, however, always be set up costs. The main costs will be the civil

works involved in site preparation and the cost of electrical and generating equipment.

However, there are certain innovations available for micro-hydro that can significantly

reduce these costs. The following list has been compiled from the Practical Action micro-

hydro website. [16]

Use of run-of-the-river schemes (eliminates need for water storing dam)


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2.11 Management/ownership

Ideally a “village electrification committee” would be put in place. This governing body

would be responsible for the continuous operation, maintenance and tariff calculation and

collection. External influence and control would be necessary, at least in the early stages of

the scheme, to ensure that all processes are followed correctly and that proper care is taken

in maintenance.

This external influence would, however, need to take great care to respect the

requirements, wishes and customs of the local community. The villagers will always know

best what they need and in what shape they need it and so it is important to work very

closely with village leaders and to maintain a good relationship with them. All decisions

must be made with the best interest of the community in mind.


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Section III - Feasibility Study

The objective of this section is to analyze the proposed site using and applying the tools

discussed in the literature review. This will give a complete illustration of how well Sioma

is suited to the implementation of a micro-hydro scheme and if its realization is viable.

3.1 Geographical situation

Zambia Country Profile [17]

Full name: Republic of Zambia

Population: 12.2 million (UN, 2008)

Capital: Lusaka


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shattering the economy. Copper mining is still the country’s main source of income, despite

the World Bank’s urges to develop other sources of additional revenue.

AIDS is blamed for many of the country’s troubles, especially the loss of many of its prime

engineers and politicians. Malaria still causes large problems for Zambia’s population and a

large proportion of the population live below the World Bank poverty threshold of 1$ a day.

Sioma

Sioma, with an estimated surrounding population of 1500 people, is located in the

Barotseland region of South Western Zambia. It is situated approximately 315 km from

Livingstone, accessible by 4x4 through a journey taking 4 to 5 hours. The village is situated

next to the majestic Zambezi River and is approximately 6 km north of the Sioma Falls by

road. The planned community woodworking workshop is approximately 4 km south of the


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A main power cable passes through the region relatively close to Sioma, but the Zambian

government has no plans to install a sub-station to make the power available to the

community. The community is too small and does not possess the ability to pay the

standard fees that would be demanded by the national electricity company. If the

community is to overcome the difficulties it faces, there is an urgent need for electricity,

one of the most basic elements of infrastructure and so alternative sources must be

considered. Due to the village’s proximity to the Zambezi River, micro-hydro provides the

ideal alternative.

This proximity does not come without difficulties, however. As I write this, Zambia is

experiencing the worst floods in 40 years [18], with the Zambezi water levels rising to record

levels. Not only does this cause severe humanitarian problems, with entire villages being

flooded, but it also makes the hydro site very difficult to design. If the intake is designed for


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3.2 Initial Planning and Technical Analysis

3.2.1 Power Requirements

The power requirements must be estimated prior to any technical analysis, as it forms the

basis of what we are designing. The focus of this proposal is the end-user rather than the

technology; it is their needs we are trying to meet. The following requirements are given as

estimates rather than facts, as a visit to the community to map out the exact needs has not

yet been made. In addition, the potential demand does not equal the present consumption.

The energy demand will be continuously changing, and with economic development,

consumption will increase.

Woodworking Workshop:

- Band Saw - 5000 W


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Village

- Households (2 light bulbs each x 200 households) - 8000 W

- Shared refrigerator (between 10 houses?) - 10000 W

- Miscellaneous (TV/Radios/kettles/mobiles etc) - 4000 W

School

- Lighting - 200 W

- Communication (TV/Radios) - 500 W

- Total - 45.83 kW

Our proposed site does not have limitations on a micro-hydro scale with respect to the

theoretical power output, but is rather limited by economic factors. The population of the


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17:00. An increase in use of televisions and radios will be seen around 18:00-19:00, which is

when we see the peak energy use; 35 kW. We can calculate the load factor using the chart

below:

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

%

T o t a l P o w

e r U s e d

Calculating Load Factor


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The load factor is a measure of how much the scheme is used, and in that sense, a measure

of efficiency. A factor of close to 57% is quite high relative to other similar schemes, and

demonstrates the viability of implementing such a scheme.

3.2.2 Measurement of Head

Often this task is assumed to require a surveyor; however, this may not be entirely

necessarily, and much quicker and more cost effective methods can be employed. Of these

methods, the level is preferred not only due to its simplicity but also due to its relatively low

cost. A carpenter’s level is the cheapest option but a Locke hand level can also be used.

Accuracy will generally be around 5%, but this is dependent on the steepness of the slope.

[11]

Using the level method, you begin at point X (in figure 16) which is the proposed location of


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Figure 16 – Using a level to measure head [11]

This method provides a relatively accurate, quick and effective way of measuring the gross

head of a site. It must be taken into account, however, that the available power from a

turbine will be proportional to H3/2, and so the measurements will have a severe effect on

any inaccuracies.


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The figures given above cannot be used accurately, however, to design intake barriers and

diversion belts as the exact site of the scheme is not yet known. The depth of water and the

width of the exact portion of the river are not known and so all dimensions derived from

this information must be taken as estimates.

3.2.4 Turbine

Importing existing turbines will often provide a fully functional and effective method of

power generation. However, it can be very expensive and will lead to difficulties when a

part needs replacing or when maintenance is required. This is why we will opt for local

manufacture, where flexibility of design is important. This design will need a relatively large

tolerance to deviations due to the method of fabrication, and so will need to function


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• Easy fabrication so it is possible to make in small, local workshops with basic tools.

• Use local materials. It was decided that the materials should be easily obtained

locally in the country of development.

• Easy operation and low maintenance through lengthy periods of operation.

Figure 17 – L-1 turbine casing and propeller [15]


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Figure 18 demonstrates that

would generate 46.1 kW

requirement will be used in t

3.2.5 Design o

Warwick

the L-1 turbine is adaptable to our parti

f power from a 10 metre head. This

e following proposed design.

intake and canal

0602641

ular site, where it

power generation


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harsh forces in the wet season. In order to facilitate this deflection it is important to use a

narrow portion of the river.

In the event that flows larger than those required by the turbine enter the canal, we will

make use of two spillways. One will be situated soon after the intake, as demonstrated in

the sketch, and the other at the site of the forebay tank. The latter will be used during

times where less power is required of the turbine.

Determining the cross sectional dimensions of canal:

Power Required = 46 100 KW

mQreq

Q

QH P req

/587.0

10**81.9*1000*8.046100

3


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22935.0

2

587.0

m A

A

V

Q A

In order to maximize efficiency a trapezoidal cross section will be used for the power

conduit. However, if excavation proves to be difficult a rectangular cross section can also be

employed.

To determine the hydraulic radius, r we will use the following equation in order to achieve

the most efficient canal section.

r

Ar

2935.0)70cos(2

)70sin(50.0

)cos(2

)sin(50.0


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0133.0

)

204.0

2*02.0(

)(

2

3

2

2

3

2

S

S r

nvS

This slope equates to a drop of 1.33 metres per 100 metres.

Figure 20 – Cross section of power conduit

Without exact figures on the river flow at the particular site it is difficult to propose a flood

0.868 m

0.204

mΘ = 70°


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In order to prevent water borne debris from entering the canal a trashrack will be used.

This will be removable to allow for maintenance and cleaning. The spacing of the bars will

be equal to that of a rake in order to facilitate the removal of debris.

Due to the proposed speed of the water in the canal sediment suspended in the incoming

water settling should not prove problematic to the flow of the canal. It is only at lower

velocities that this will settle and disrupt flow. However, a settling basin will be required at

the forebay to prevent destructive particles getting through to the turbine and causing

premature erosion.

As mentioned earlier, the scheme will incorporate two spillways. The overflow spillway will

be located close to the intake and will be constructed as “broad crested”. This does not

pass the largest flow per unit of length, but is the simplest to construct.


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In the event of flow entering the forebay and exceeding that passing through the penstock,

an overflow spillway will be required. This water will then be diverted back to the river on a

dedicated path – preventing uncontrolled erosion. A trashrack will also be required, to

remove any floating debris which may have gotten through the intake or entered the canal

through other means. A drain will also be installed to empty the tank when maintenance is

required so that settled sediment can be removed. A width and depth of 1.5 m and a length

of 2 m is appropriate. Figure 21 illustrates a design that would work well at our site.

Instead of a perforated PVC pipe for filtration, however, a metal trashrack will be used.

Taps will also be fitted to the side as discussed earlier.


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3.2.7 Penstock

Typically the Penstock represents 1/3 of total scheme costs. [22] The various alternatives, in

terms of both size and material, must therefore be considered carefully. We are aiming to

maximize the power per unit length and determining a realistic slope.

At this point in the planning process, the specific site is not known so estimates about the

required pipe length and slope must be made. For this analysis we will use the height and

length estimates given in the diagram below.

Forebay

51 m

10 m


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Upon comparison of uPVC and HDPE, it quickly becomes clear that HDPE has numerous

advantages over uPVC [23]. It is flexible, whereas uPVC is rigid and so requires more joining

as well as a well as very comprehensive support. HDPE piping can simply be laid on the

ground, where it will flex to the changing slope adequately. uPVC pipes need trenches to

provide continual support, as well as covering to protect from UV corrosion. HDPE pipes do

not suffer from UV corrosion; they have high impact strength as well as high chemical

resistance. Compared to uPVC pipes they are very easy to install as well as join, and so,

bearing all the factors considered in mind, HDPE pipes clearly provide a superior alternative.

Optimal Diameter:

First it is necessary to determine the optimal diameter of the penstock pipe. This will be a

compromise between the % head loss and the cost of the pipe, which is generally defined by


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Although this is less significant in low head penstocks, it is still a factor, and so a pipe with

minimum wall thickness of 16.2 mm must be selected. [11] Calculations also show that the

critical shut off time is 0.59 seconds. The penstock will have a gate valve at the bottom

which must not be closed faster than this, if it is, the penstock will experience the maximum

pressure of the water. These calculations can be found in Appendix B.

Thermal Expansion of the Penstock:

Temperatures in Zambia can vary by as much as 29°C [24] and as a result the HDPE penstock

will suffer significant thermal expansion. This was calculated to be as much as 0.177 metres

for 51 metres of piping, as can be seen in Appendix C. The use of HDPE allows for the bends

in the piping to take up any expansion or contraction between the anchor points. If a more

rigid material was used, this stress would be transferred to the anchor blocks in the manner


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previous section. The piping will, however, have to be secured by anchor blocks to ensure

the stability of the penstock. The piping should be secured by 3 anchor blocks, each block

made up of 2m3

of concrete – 1 m3

per 300mm diameter of piping

Control Measures:

Controlling flow into the penstock is an important element to allow for maintenance of the

turbine, or the piping itself. Control can be achieved through a variety of means, by using

gate valves or even a simple construction such as that shown in Appendix D.

This construction is rubber faced, with a steel tube handle. Its face is placed onto the

penstock intake, where the water pressure maintains it, and blocks further water from

entering. To avoid fracture through vacuum, a vent pipe can be placed close to the intake

along the piping – as is also shown in Appendix D.


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AC system will be employed, with a step-down transformer at the end users. In order to

avoid the use of a step up transformer at the turbine site a high voltage generator will be

used.


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3.3 The potential contribution to the local community

Local Clinic

The scheme would replace the diesel generator currently in place. The clinic does not

currently have sufficient funds to purchase diesel to run this and so is using temporary solar

panels – which are proving themselves to be problematic. A reliable and sustainable

electricity source such as the hydroelectric scheme would allow for easier operation of

medical equipment, treatment, refrigeration, computers, lighting and increased comfort.

The clinic also suffers from the lack of a permanent doctor. The availability of electricity

may give the clinic a substantially greater appeal to a doctor and encourage the clinics

expansion.


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an education nonetheless. This will provide opportunities that were unthinkable earlier,

and will be an important development in terms of community progression.

Woodworking Workshop

The community woodwork training workshop is a ZEEC initiative, started a few years ago.

The idea is to provide a centre of training for the local community in woodworking skills in

order to encourage local businesses and develop self-sufficiency. The centre has not yet

been built, but has a planned site and permission.

The problem with powering this is that it is situated south of the Sioma Falls, and so

separate wiring for this site would be required. The distance to it, however, is smaller –

approximately 4 km. If it proved viable to power this alongside the community it could be

made commercially viable as furniture produced could be sold at competitive prices, which


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The availability of electricity would make Sioma an important hub of the surrounding area,

attracting much more activity.

Integration with irrigation and water supply projects

Due to the mechanical movement produced by the moving water, the scheme can be

integrated with both irrigation and water supply projects to supply the area around the site.

This is especially achievable due to the surrounding fields of the area. These are not

currently used for agriculture but have been in the past, as there are remnants of old

irrigation canals close to the proposed site.

The socio-economic benefits of the scheme are summarised below:


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Woodworking Workshop

The woodworking workshop will be manufacturing furniture to be sold for profit. This

means that, if successful, there will be funds to pay for the electricity. This tariff will be set a

level lower than the cost of running a diesel generator but enough to pay for necessary

maintenance as well as spare parts for the turbine, and will be measured through a metre.

The income from this beneficiary will be the main source for return on investment.

In order to determine an appropriate charge, the competition’s price, diesel, must be

considered. Running a 30 kW generator at ½ power for 8 hours consumes approximately

54.4 litres per day [25]. At current UK diesel prices this equates to £63 per day [26], which is

a total of £16,380 in a working year (260 days). The actual price is expected to be higher

however, as fuel prices in Zambia are higher than in the UK. Clearly, this price does not


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3.5 Ownership

The ownership of the scheme is important to clarify if the scheme is to be implemented in

the future. A proposed model is shown in Figure 25.

ZEEC

Registered Charity in

Zambia

ZEEC has links to several

schools, universities and

organizations in Europe and

USA, who will raise financial

support for the initial costs of

project

ZEEC works with local and

national government, ZESCO,

NGOs etc.

ZEEC trustees are people from

both Zambia as well as W estern

countries, connected to the area

and with common goals

Pro osed Structure of Ownershi and External Relations for Micro-H dro Scheme


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generated from electricity tariffs. Any profit after maintenance and salary costs will be

reinvested into new development projects for the region.

The majority of funding will presumably be raised by ZEEC and so a significant influence on

the Sioma Power Company’s future decisions is to be expected, possibly by electing ZEEC

trustees to its board of directors.


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3.6 Meeting with ZEEC

One meeting with a ZEEC representative, Joachim Meyer, was held in Brussels along with

numerous e-mail communications. The idea of the micro-hydro scheme was introduced to

Mr. Meyer via e-mail in mid October, which was received positively. It was agreed to meet

in March so that the project could be set in motion as quickly as possible.

Building permission was discussed, and although an application has been sent, nothing has

yet been heard. Mr. Meyer assured me that rumours are positive and that a positive

response is almost certain but that such requests take time. The current flooding was next

on the agenda – and the floods’ impact on design was stressed. Finally a list of questions

and observations was handed to Lesley Meyer who was planning a trip to Sioma in April, to

help with the writing of this report.


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Section IV – Conclusions and Recommendations

4.1 Conclusions

In order to break out of the poverty cycle, third world infrastructure development is crucial.

It is clear from the past analysis that micro-hydropower is one of the most important energy

sources for achieving this wherever pressurised water is available. It is a relatively

affordable, clean and completely renewable technology that has proven its effectiveness

over many decades.

This report has given an insight into the technology behind micro-hydro schemes and the

most efficient ways of implementing them. After a comprehensive literature review of the

subject, the theory was applied to the case of Sioma in Zambia. Based on estimates from


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4.2 Costing of Project

Date Person(s)/item(s) Time

(hours) Cost (£) Comment

30/09/2008 Dr. S.C. Li 0.5 25 Staff (Supervisor)




18/02/2009 Nigel Sykes & Tom McCluskey 3 150 Staff (Nigel Sykes & Tom McCluskey)

25/03/2009 Joachim Meyer 2 100 Staff (ZEEC)


350

1/10/08-

21/4/09 Hans Petter Bjornavold 300 4500 Student (30 CATs = 300 hours)

4900

09/01/2009 Micro-Hydro Sourcebook 24.94 Consumable (book)

Total 5274.94

Figure 26 – Costing of Project


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4.3 Recommendations

In the extent that this study goes, the Sioma micro-hydropower scheme has proved itself

viable. The project would bring vast benefits to the Sioma community and its surrounding

area, with a relatively reasonable cost.

In order to develop the project further, in a minimal amount of time, a trip to the area in

June 2009 is recommended. This will allow the author to perform key surveying of potential

sites, as well as to gain a clearer perspective of the true requirements of the community. In

addition the author will be able to map out the potential of local labour and the possible

suppliers of parts.

Following this trip, extensive planning using the detailed measurements made in June will

have to be performed. The turbine will be sourced, as will the HDPE piping. Arrangements


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Glossary of Definitions

Coupling – connecting the rotating turbine to electrical generator/mechanical

equipment.

Forebay – water reservoir immediately upstream of penstock

Generator – an engine that converts mechanical energy into electrical energy

HDPE – high density polyethylene

Kinetic Energy – energy due to motion

Micro-Hydropower – small scale harnessing of energy from falling water

Sioma – Village with population of approx. 1000-1500 in Barotseland, South Western

Zambia

Penstock – piping directing water from forebay to turbine

Potential Energy – stored energy


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References/Bibliography

[1] TAMBURRINI, M., 2004, A Feasibility Study for a Microhydro Installation for the Strangford

Lough Wildfowlers & Conservation Association, Thesis (Msc), University of Strathclyde

[2] Hydropower Fundamentals, http://www.alternative-energy-

resources.net/hydroelectricity.html, retrieved 20 March 2009

[3] REN21, Renewables – Global Status Report 2006 Update,

http://www.ren21.net/globalstatusreport/download/RE_GSR_2006_Update.pdf, retrieved April

19 2009

[4] International Energy Agency, Renewable Energy – Status and Prospects, 2003

[5] USGS, Hydroelectric Power Water Use, http://ga.water.usgs.gov/edu/wuhy.html, retrievedFebruary 10 2009

[6] UN Economic and Social Council, Access to Electricity ,

http://webapps01.un.org/nvp/frontend!polCat.action?id=50, retrieved February 15 2009


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[16] Micro Hydropower Introduction,

http://practicalaction.org/practicalanswers/product_info.php?cPath=21_63&products_id=41,

retrieved 19 April 2009

[17] Country Profile: Zambia, 2009,

http://news.bbc.co.uk/1/hi/world/africa/country_profiles/1069294.stm, retrieved February

2009

[18] NYAKAIRU, F., Zambia and Namibia face worst floods in 40 years,

http://www.reuters.com/article/africaCrisis/idUSL0976837, retrieved 26 March 2009

[19] Zambezi River – Hydrology , http://www.britannica.com/EBchecked/topic/655540/Zambezi-

River/37114/Hydrology, retrieved March 26 2009

[20] Buckland, R., Micro Hydro at Las Juntas: Analysis of the scheme to date and the Socio-

economic, Environmental and Political Effects, 3rd

Year Project, University of Warwick

[21] McMULLEN, C., Low Head Micro Hydro in Developing Countries: The L-1 Turbine, April 2004,

3rd

Year Project, University of Warwick


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Appendix A

Head Loss for different diameter pipes:

Q net Q net Q 2 Lpipe n d d2 d5,3 hwall

lossv v2 k

hturb

loss

hfriction

losshgross

%

loss price/m

l/s m3/s m m m m/s m m m $

510 0,51 0,26 51 0,01 0,32 0,10 0,00 5,56 6,35 40,26 0,5 1,03 6,59 10 65,90 N/A*

510 0,51 0,26 51 0,01 0,37 0,14 0,01 2,58 4,75 22,53 0,5 0,57 3,15 10 31,52 N/A

510 0,51 0,26 51 0,01 0,42 0,18 0,01 1,32 3,68 13,57 0,5 0,35 1,66 10 16,62 N/A

510 0,51 0,26 51 0,01 0,5 0,25 0,03 0,52 2,60 6,75 0,5 0,17 0,69 10 6,95 N/A

510 0,51 0,26 51 0,01 0,55 0,30 0,04 0,32 2,15 4,61 0,5 0,12 0,43 10 4,33 N/A

510 0 51 0 26 51 0 01 0 6 0 36 0 07 0 20 1 80 3 26 0 5 0 08 0 28 10 2 82 N/A


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Appendix B

Wall thickness:

Minimum wall thickness according to ASME code is:

mmt

Dt

2.16

2.1*5.2

min

min

Water hammer pressures can occur when the critical shut off time is not observed. To find

this we first find the wave velocity:

sma

t E

D K a

/02.173

*

**10001

1420


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Appendix C

Thermal Expansion:

If an unrestricted HDPE pipe, length “L = 0.51”, changes in temperature, there will be a

change in its length equal to:

m L

T a L L

177.0

**

Where T = change in temperature (°C) = 35-6 = 29

a = coefficient of linear expansion (°C-1) = 120*10^-6 °C-1


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Appendix D

Penstock inlet control:

Warwick 0602641


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Appendix E

Demand Estimate:

Time Total Power Used Total Power Used Percentage of Comments

1 0.5 7 18.8%

2 0.5 6 16.3%

3 0.5 6 16.3%

4 0.5 6 16.3%

5 0.5 6 16.3%

6 0.5 8 21.3%

7 0.5 9 23.8% Increase in lighting in village

8 15 8 57.5% W.W working day begins

9 20 8 70.0%10 20 8 70.0%

11 20 8 70.0%

12 20 8 70.0%

13 10 8 45.0%

14 20 8 70.0%

15 20 8 70.0%

h l f f k


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Appendix F

Item Cost (£) CommentPlanning 4000 200 hours at 20 pounds per hour

Management 800

Overseeing the project during construction (local

expert)

Intake

Concrete 1000

Labour 20Total 1020

Spillway

Total 200

Canal

Concrete 5000

Labour 70

Total 5070Forebay tank

Concrete 500

Labour 50

Trashrack 200

Cover 5

Drain 15

S h l f E i i U i i f W i k 0602641


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Appendix G

Project Costs:

Date Person(s)/item(s) Time

(hours) Cost (£) Comment





18/02/2009 Nigel Sykes & Tom McCluskey 3 150 Staff (Nigel Sykes & Tom McCluskey)

25/03/2009 Joachim Meyer 2 100 Staff (ZEEC)


350

S h l f E i i U i it f W i k 0602641


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Appendix H

ZEEC correspondences:

18/10/2008 from me to Leslie and Joachim Meyer

Mr. and Mrs. Meyer,

Hope you're both well and that the new school year is going smoothly. Thanks for the update back in

September - exciting news about the truck!

I have some news I thought might interest you! I've been allocated a project based on small scale

hydro-electric power for isolated communities in developing countries. All similar projects in recent

years (from this supervisor) have been based on a village in Peru but, since I found continuing the

pattern a bit dull, I proposed doing my own thing and focusing my project on the implementation of

such a scheme in Sioma and coming up with a proposal. My supervisor was happy supporting this so

it is now officially my third year project, counting for 1/4 of this year. If I manage to come up with a

decent proposal and the idea proves itself beneficial as well as viable I do plan to pursue the project

past the academic "boundaries" which hopefully would result in concrete advancements for the

community of Sioma.

S h l f E i i U i it f W i k 0602641


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Best regards,

Joachim

22/10/2008 from me to Joachim Meyer

As I see it now, the scheme would produce enough electricity for all of Sioma as well as the

community training workshop. Of course this is very ambitious and would prove to be quite

expensive. Projects of similar scale have cost approximately $50,000 (US) but have proven very

effective in increasing not only quality of life but also attracting new businesses and revamping the

local economy.

An interesting project just being finished is the North West Zambia Development Trust

(www.nwzdt.org) - it gives an idea of what can be achieved. It is on a much bigger scale though, with

an output of approx 700KW whereas I am aiming for approx 30KW for Sioma.

I will be working on a more complete plan throughout the rest of the week, aiming to have it done

by the end of the weekend. I can then send it to you and, if you approve, we can pass it on to Joe

and the local authorities. If we get their backing, I imagine it will be easier to apply to various

charities for support. I do have a copy of the request for the establishment of the training workshop,

I assume it is the one I have attached?

Also, do you have an idea of the machinery that would be needed for the training workshop? It

would be useful in order to calculate the required power output for the turbine.

School of Engineering University of Warwick 0602641


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28/10/2008 from me to Joachim Meyer

Hi,

I have attached a brief letter/plan for the local government asking for a letter of support. Will we be

able to use this (or something like it)? If you have any suggestions please let me know.

Thanks,

Hans

2008/10/28 from Joachim Meyer to me

Good morning hans,

I have had a long conversation with Joe this morning. He would be delighted to assist in any way.

The Western Province has recently suffered lengthy power cuts because development of economic

activity and power supply are not balanced.

I am sending your proposal to Joe who will in a week's time have a meeting with the minister of

energy for the Western Province and he is sure that you proposal will be supported and a letter send

to you.

This will work,

Joachim



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Hello,

Not much feedback at this stage. But what we have sound promising.

Joe has met with the Director of Zesco responsible for the Western Province. You proposal outline is

therefore sitting on the desk of the top man running the Zambian Electricity Supply Company in the

area.

We await their reaction. I think it would be good to have their support particularly when it comes to

maintain the facility later.

Joachim


Hello Hans Petter,

Below a response from Joe the project looks like it will be signed off by the LOZI parliament KUTA.

All the best,

Joachim Meyer

22/1/2009 from Joe to Joachim Meyer


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14/11/2008 from me to Vanessa Scott

Dear Vanessa,

Thanks for your very quick reply! I'm glad to hear you approve of the project, I am currently waiting

for a letter of support from Zesco (Zambian Electricity Supply Company) in the Western Province,

which should hopefully help in terms of funding applications and other practicalities.

As far as other information goes, I'm in close contact with Mr and Mrs Meyer so they've been able to

help a lot. If there is anything else though I will make sure to contact you.

Hopefully I'll be heading to Sioma during my easter break, but I can't confirm that yet due to certain

practical issues. If not, I'll be aiming for a trip in July or August. Of course, this all depends on the

outcome of my research and the acquisition of funding.

I'll keep you updated on any news,

Kind regards, Hans

1/1/2009 Vanessa Scott to me

> Dear Hans,

> Please see the email below from Sister Catherine. I hope this information

> helps?



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6/1/09 me to Vanessa Scott and Richard White

Dear Vanessa and Richard,

Thank you very much for your help, I can only apologise for such a late reply. If you have some more

general statistics on the clinic, this would be very helpful (as in how many people are treated there a

year, the max. Amount of patients at one time, the amount of staff etc.), simply so I can provide a

more detailed picture of the requirements for my report.

As for updates, I have a progress report due for the project on Friday, so I will pass this on to you

over the weekend.

Kind regards,

Hans


Dear Hans,

I wanted to check in with you regarding your project for Sioma and also let you know that our

program will be sending two groups of students to Sioma this summer. One in May/June, and

another group in August.

Please let me know if you need me to have them collect any information or data on your behalf!



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Dear Hans,

Please tell Joachim hello for me! He was in Sioma with me in August of 2007.

Let me know if you have any assignments for the students going down there in May/June or in

August, I'm happy to give them any sort of project!

Cheers,

Vanessa

27/3/2009 me to Vanessa Scott

Hello again!

I met with Joachim and Lesley yesterday afternoon and had a long chat with them regarding the

project and Sioma in general. They are both very motivated to work with me on the project, which is

great. Mrs. M is actually off to Sioma tomorrow evening with a group of 22 students from the

European School and so I gave her a list of questions and issues that I asked her to make notes on. If

there is anything else I need notes on I will make sure to let you know, but it is difficult to give

instructions on possible site locations etc over e-mail and not in person.

However, it looks like I might be able to go travel down there in early June with Joachim (as long as

my provisional exam timetable doesn't change), which would be fantastic and would really help the



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Appendix J

Sioma Falls from the air:



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Appendix K

Satellite image of Sioma Falls area:



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Appendix L

Gannt Chart of Project Work:

We ek* 1 2 3 4 5 6 7 8 9 10 Christmas Bre ak 11 12 13 14 15 16 17 18 19 20 Easter Bre ak 2 1 22

Literature Review

Initiate Contact with ZEEC

Produce Plan for ZEEC/Zambia

Initiate Contact with Zambia / Apllication for backing of local government

Initiate Contact with NWZDT

Research possible sponsors for trip/project as a whole

Meeting with ZEEC in Brussels / Discussion in further detail

Apply to Lord Rootes Memorial Fund + other potential sponsors

Organise notes - finalise structure

Writing of report

Finish draft report

Review s uggestions/changes

Finalisation of report

Preparation of oral report

* Note: Academic weeks. Start date: 29.09.2008 End date: 01.05.2009

Documents

Hans Petter Bjornavold_Implementation of a Microhydro Power Scheme_2009_REPORT