` PROPOSING SUSTAINABLE SMALL HYDRO POWER PLANT FOR RURAL SETTING A Case Study of Kilondo Village Ludewa Emmanuel Anosisye Mwangomo Msc. (Renewable Energy) Dissertation University of Dar es salaam December 2010
Oct 14, 2014
` PROPOSING SUSTAINABLE SMALL HYDRO POWER PLANT
FOR RURAL SETTING
A Case Study of Kilondo Village Ludewa
Emmanuel Anosisye Mwangomo
Msc. (Renewable Energy) Dissertation
University of Dar es salaam
December 2010
PROPOSING SUSTAINABLE SMALL HYDRO POWER PLANT FOR
RURAL SETTING
A Case Study of Kilondo Village Ludewa
By
Emmanuel Anosisye Mwangomo
A Dissertation Submitted in (Partial) Fulfillment of the Requirement for the Degree of
Master of Science in Renewable Energy of the University of Dar es salaam
University of Dar es salaam
December, 2010
i
CERTIFICATION
The undersigned certifies that he has read and hereby recommends for acceptance by the
University of Dar es salaam a dissertation entitled, “Proposing Sustainable Small
Hydro Power Plant for Rural setting. A case study of Kilondo village Ludewa”, in
partial fulfillment of the requirements for the degree of Master of Science in Renewable
Energy of the University of Dar es salaam.
_________________________________
Dr. P.M. Ndomba
(Supervisor)
Date: _________________________
ii
DECLARATION
AND
COPYRIGHT
I, Emmanuel Anosisye Mwangomo, declare that this dissertation is my own original
work and that it has not been presented and will not be presented to any other university
for a similar or any other degree.
Signature………………………………
This dissertation is copyright material protected under the Berne Convection, in the
Copyright Act of 1999 and other international and national enactments, in that behalf, on
intellectual property. It may not be reproduced by any means, in full or in part, except
for short extracts in fair dealing, for research or private study, critical scholarly review
or discourse with an acknowledgment, without written permission of the Director of
Postgraduate Studies, on behalf of both the author and the University of Dar es salaam.
iii
ACKNOWLEGDEMENT
The completion of this work owes much gratitude to many people. It is difficult to
mention them all, however, the following deserve my special thanks for their
contribution and support towards completion of this work.
First of all, I would like to thank God who made all this possible.
Second I would like to thank my supervisor, Dr. P.M. Ndomba, for his intellectual
stimulation, guidance, patience and valuable detailed comments, which enabled this
work to be accomplished. Any shortcoming in the dissertation should however, be solely
blamed on me. My gratitude also goes to the College of Engineering and Technology
(UDSM) for training me in various ways both in the classrooms and outside.
I am indebted, to the Principal and management of Mbeya Institute of Science and
Technology who enabled me to be trained at University of Dar es Salaam, by granting
me financial assistance during my study without which this study would not have been
possible. I also thank Nile Basin Capacity Building Network (NBCN-SEC) for co-
sponsoring the data collection activities.
I would like to extend my sincere gratitude to the following institutions for providing
me with relevant data and information: Ministry of Water and Irrigation, Ministry of
Land and Human Settlement Map Division, Tanzania Electricity Supply Company
(TANESCO), and Kilondo ward office.
I thank Mr. Erick Mwambeleko for hosting me during my visit at Kilondo Village.
Lastly I thank my dear wife Lydia and my kid Michelle together with my classmates for
their cooperation during the whole period of my studies.
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DEDICATION
To my mother Tabitha Andembwisye Sankonga Mwangomo
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ABSTRACT The remoteness of Kilondo village and its topography makes it difficult to be
connected from the national electric grid. A centralized stand alone hydropower plant
can therefore make a sustainable solution for Kilondo village electrification. The
methods used in this study included: assessing electricity demand; identifying potential
hydropower sites; estimating stream flow regime; conducting preliminary design and
environmental, social and economic appraisal of project. Energy demand survey for
Kilondo village was done and 348 potential consumers and with a diversified market
demand of 86.7 kW was identified. Kilondo River has a potential of producing
electricity by using hydro turbo-generator. The proposed site has a gross head of 117m
and designed flow of 19m3/s and can produce power of 15.6MW which is obtained in a
95% of the time. RETScreen module was used to validate the data calculated manually
and power obtained from the module was 18 MW. Annual energy production estimated
from the module was 130375MWh and the anticipated revenue to be collected is $
6,511,445. The proposed Kilondo hydropower project has been analyzed, its benefits
have been maximized and negative environmental, social and economic impacts have
been minimized so it is sustainable. Based on the analytical work and experimental
investigation an appropriate small hydropower plant for producing electricity for rural
settlement has been proposed which has negative impact on the environment and
positive impact to social welfare of Kilondo people. The limitation of this project is that
it is isolated and anticipated power to be produced exceeds demand of Kilondo village. It
requires another cost of building infrastructure of transmitting electricity to the national
grid; this transmission cost will increase the payback ratio. For the Kilondo hydropower
scheme to be sustainable there is a need to recognize entitlements and share benefits
with directly affected people. The goal should be to ensure that all individuals and
communities affected by developments gain sustainable benefits.
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TABLE OF CONTENTS
Page
Certification........................................................................................................................i
Declaration And Copy Right..........................................................................ii
Acknowlegdement..............................................................................................iii
Dedication.........................................................................................................................iv
Abstract.............................................................................................................................v
Table Of Contents............................................................................................................vi
List Of Tables....................................................................................................................xi
List Of
Figure....................................................................................................................xii
Abbreviations..................................................................................................................xiv
List Of Symbols..............................................................................................................xvi
CHAPTER ONE:INTRODUCTION 1
1.1. General Introduction ............................................................................................... 1
1.2 General description of the study area ...................................................................... 6
1.2.1 Social economic activities of Kilondo Village...................................................... 10
1.3 Statement of the Problem ...................................................................................... 12
1.4 Objective of the Research ..................................................................................... 13
1.4.1 Main Objective ...................................................................................................... 13
1.4.2 Specific Objective ................................................................................................. 13
1.5 Research Questions ............................................................................................... 14
1.6 Expected output ..................................................................................................... 14
1.7 Significancy of the Study ...................................................................................... 14
1.8 Scope of the Study ................................................................................................ 15
vii
1.9 Organization of the Study ..................................................................................... 15
CHAPTER TWO:LITERATURE REVIEW 16
2.1 Sustainable Energy ................................................................................................ 16
2.2 Reneawable Energy ............................................................................................... 16
2.3 Hydropower Development .................................................................................... 17
2.3.1 Small hydro power plant overview ...................................................................... 18
2.3.2 Large Hydropower plant overview ...................................................................... 19
2.4 Rural areas ............................................................................................................ 19
2.4.1 Effects of rural electrification .............................................................................. 19
2.5 Significance of small hydro power plant ............................................................. 20
2.6 Components of Small Hydro power plants .......................................................... 21
2.7 Types of Hydro-Electric Schemes ....................................................................... 21
2.7.4 Pumped Storage ................................................................................................... 22
2.8 Types of Turbines ................................................................................................ 22
2.9 Turbine Selection ................................................................................................. 24
2.10 Suitable Condition for Small Hydro Power Plants .............................................. 25
2.11 Hydro Power Generation ..................................................................................... 26
2.11.1 Conversion of Water Power to Electricity .......................................................... 26
2.11.2 Preliminary power and energy calculation .......................................................... 26
2.11.3 Design Flow ........................................................................................................ 27
2.11.4 Capacity Factor ................................................................................................... 27
2.11.5 Rated Power ........................................................................................................ 28
2.11.6 Energy Output ..................................................................................................... 28
2.12. Stream Flow Estimation Methods ....................................................................... 28
2.12.6. Floating Body Method ........................................................................................ 29
2.13. Hydrological data analysis .................................................................................. 30
2.13.1 Rating curve ........................................................................................................ 30
2.13.2 Flow Duration Curve .......................................................................................... 32
2.13.3 Load duration curve ............................................................................................ 32
viii
2.14 Environmental Impact Assessment (EIA) ............................................................ 33
2.15. Social Impact Assessment (SIA) .......................................................................... 33
2.16. Electrical Demand Analysis ................................................................................ 34
2.16.1 Trend analysis ..................................................................................................... 34
12.16.2 End use approach method .................................................................................. 34
2.16.3 Econometric approach method ............................................................................. 35
2.16.4 Load and Energy Forecast .................................................................................... 36
2.17 Economical Appraisal .......................................................................................... 37
2.18. RET Screen Model ............................................................................................... 38
2.18.1 RET Screen Small Hydro Project Module ........................................................... 38
2.18.4 Limitation of RET Screen Small Hydro Project Model ....................................... 39
CHAPTER THREE:METHODS AND MATERIALS 41
3.1. Data Collection..................................................................................................... 41
3.2 PreliminaryElectricity Demand Assessment ........................................................ 42
3.3 Identify potential hydro power sites. .................................................................... 43
3.4 Estimate stream flow of the River. ....................................................................... 43
3.5 Hydrological Modeling ........................................................................................ 44
3.6 Environmental impact assessment ....................................................................... 44
3.7 Social Impact Assessment ..................................................................................... 45
3.8 Preliminary Design of Small Hydro power Plant .................................................. 45
3.9 Economic analysis ................................................................................................. 46
CHAPTER FOUR:DATA COLLECTION AND ANALYSIS 48
4.1 Data Collection...................................................................................................... 48
4.1.1 Rainfall Data ......................................................................................................... 48
4.1.2 Hydrologic Data .................................................................................................... 48
4.1.3 Drainage area ........................................................................................................ 49
4.1.4 Stream velocity...................................................................................................... 49
4.1.5 Cross sectional area of the Kilondo River............................................................. 50
4.1.6 Stream Discharge of Kilondo River ...................................................................... 52
ix
4.1.7 Environmental and Social Impact assessment ...................................................... 52
4.1.8 Number of identified consumers in Kilondo Village ............................................ 53
4.2 Data Analysis ........................................................................................................ 53
4.2.1 Introduction ........................................................................................................... 53
4.2.2 Data preparation .................................................................................................... 53
4.2.3 Mean Annual Flow for gauged site ...................................................................... 54
4.3 Flow-duration curve for gauged catchment ......................................................... 54
4.4 Estimating mean annual flow for ungauged catchment ....................................... 57
4.5 Correlation Analysis ............................................................................................ 58
4.6 Estimating a flow-duration curve for ungauged catchment ................................. 60
4.7 Identification of potential micro hydropower plant site ....................................... 62
4.8 Head Measurement .............................................................................................. 64
4.9 Determining Power Potential ............................................................................... 64
4.10 Determination of load and energy demand for Kilondo village .......................... 66
4.11 Selection of Turbine ............................................................................................. 67
4.11.1 Determination of specific speed of the turbine, n (rpm) ...................................... 67
4.11.2 No. of poles, p ...................................................................................................... 68
4.11.3 Check of Cavitations ............................................................................................ 68
4.12 Design of Civil Structure ..................................................................................... 70
4.13 Social Impact Assessment .................................................................................... 80
4.14 Evironmental Impact Assessments ...................................................................... 81
4.15 Economical Appraisal .......................................................................................... 82
4.16 Hydrological Modeling ........................................................................................ 83
CHAPTER FIVE:CONCLUSION AND RECOMMENDATIONS 86
REFERFNCES 90
APPENDICES 95
APPENDIX A: Diversified Unit Load…..……………………………………….…..95
APPENDIX B: Demand Survey Questionnaire............................................................96
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APPENDIX C: Questionnaire for Households of Non-Electrified Villages..................97
APPENDIX D: Number of Identified Consumers in Kilondo-Ludewa.......................103
APPENDIX E: Load Demand Determination for Kilondo-Ludewa…………..…….105
APPENDIX F: Maximum Power in Kilondo Village.................................................106
APPENDIX H: Energy demand forecast for 25 years.................................................107
APPENDIX I: Social Safeguards Screening Checklist...............................................108
APPENDIX J: Checklist for Environmental Impact Assessment................................111
APPENDIX K: Average Monthly Rainfall (mm) for Kilondo from 1976-1980 .......... 112
Appendix M: Layout of Kilondo Hydropower Plan....................................................113
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LIST OF TABLES
Table 1: Existing electric power plant generation in Tanzania – interconnected………..2
Table 2: Variation of capacity factor with design flow……………………………...….28
Table 3: Mean Monthly Flow (m3/s) for Lumbira River from (1976-1985)…………...47
Table 4: Stream Velocities at Different Locations on May 2010……………………….48
Table 5: Mean annual flow (m3/s) for Lumbira River for the period 1976 to 1985….…52
Table 6: Shows Calculation of Daily Mean discharge and Plotting position…………...53
Table 7: Average Flows (m3/s) and Rainfall (mm) Data from 1976 – 1980…………...57
Table 8: Calculation of Karl Pearson’s coefficient of correlation (r)........................…...58
Table 9: Calculation for the flows (m3/s) of ungauged catchment...........................…....59
Table 10: Peak load (kW) for 25 years for γ = 0.25…………………………….....……64
Table 11: Vertical velocities of particles..................................................................…....74
xii
LIST OF FIGURE
Figure 1: Status of Energy Consumption in Tanzania…………………………………...1
Figure 2: Tanzania map showing small hydropower sites concentrations………...………5
Figure 3: Map of Ludwig District showing Location of Kilondo Village……………....7
Figure 4: A graph of annual hydrograph for Kilondo River ………...…………..……....9
Figure 5: Nyasa Basin Hydrometeorogical gauging stations……………………………………..9
Figure 6: Economic activities of Kilondo people……………………………….....…....11
Figure 7: Hydrologic Cycle of water……………...……………………………………17
Figure 8: Hydropower Plant System……………………………...…………………….18
Figure 9: Layout of a typical small hydro scheme……………………………..….……21
Figure 10: Francis Turbine………………………………………..………………….…24
Figure 11: Turbine Selection Chart…………………………..…………………………25
Figure. 12: Hydraulic turbine and electrical generator …………………………………26
Figure 13: Measuring the cross-sectional area of a Kilondo river…………………..….30
Figure 14: Graph of a Rating Curve………………………………………..……...……31
Figure 15: Measuring stream velocity and cross sectional area of Kilondo River……..49
Figure 16: Flows – Duration Curve for Gauged Catchment, Labial……………...….....54
Figure17 : Lumbila Catchment delineated using Arcview GIS………………………..54
Figure 18: Kilondo Catchment Area delineated using GIS……………………………..56
Figure 19: Flow Duration Curve for ungauged Kilondo catcment…………………..…60
xiii
Figure 20 :The profile of Kilondo River….…………………………………………….61
Figure 21: Kilondo River water falls(S 9° 44.23”, E 34° 18.93”)…………………........62
Figure : 22 Load Duration Curve For Kilondo River…………………………………..63
Figure 23: Cross section of Francis runner………………………………………..…….67
Figure 24: Intake and Weir……………………………………..…………………….…69
Figure 25: Section of Headrace…………………...…………………………………….72
Figure 26: Financial viability of Kilondo Hydropower plant………………………..…81
Figure 27: Flow duration and power curves of kilondo river…………………………...82
Figure 28: Graph of Francis turbine efficience ………………………………………...83
xiv
ABBREVIATIONS Abbreviations Description AHEC Alternate Hydro Energy Centre
BILA British Hydropower Association
DEM Digital Elevation Model
DNO Distribution Network
EIA Environmental Impact Assessment
EIS Environmental Impact Assessment Statement
e-RGNEPAL Environmental Resources Group
ESHA European Small Hydropower Association
FDC Flow Duration Curve
GFKF Gross fixed capital formation
GHG Green House Gas
GP Government policy
I Investment
IAIA International Association for Impact Assessment
ICT Information and Communication Technology
IEA International Energy Agency
IHA International Hydropower Association
kWh Kilowatt-hour
LDC Load Duration Curve
xv
MEM Ministry of Energy and Minerals
Mwh Megawatt hour
Nacl Sodium Chloride
NBCBN Nile Basin Capacity Building Network
NEMC National Environmental Management Council
OP Population
RETScreen Renewable Energy Technology Software
RIMA Rapid Impact Assessment
RPM Revolution per Minute
SIA Social Impact Assessment
T Technology
TANESCO Tanzania Electricity Supply Company.
TMA Tanzania Metrological Agency
TNBS Tanzania Bureau of Statistics
UDSM University of Dar-es-salaam
URT United Republic of Tanzania
ZESCO Zanzibar Electricity Supply Company
xvi
LIST OF SYMBOLS Symbols Description Unit ∀ Volume of tracer m3
A Area m2
C Roughness index -
Cd Coefficient of discharge -
CF Capacity Factor -
ct Tracer concentration
Dg Group diversity factor -
Du Diversified unit load -
E Energy consumption of an appliance kWh
g Acceleration due to gravity m/s2
∆h Head difference m
H Head m
L Notch width m
P Electrical power W
P Power required by the appliance kW
Pi Own price $
Pj Price of related fuels $
Qmean Mean Flow m3/s
0
1
CHAPTER ONE
INTRODUCTION
1.1. General Introduction Electricity is the engine of development of any society. In Tanzania only two percent of
rural population have access to electricity (MEM, 2003).The development of rural
Tanzania is very important since 80% of population in Tanzania is living in rural areas
(URT, 2002). This implies there is still an urgent need to encourage and promote the
supply of affordable energy sources in rural areas where the majority of the population
live. The current status of energy consumption in our country is dominated by biomass
which account for more than 90% of energy used. Petroleum accounts for 8% of the
total energy consumed, while grid electricity is estimated to account for only 1% of the
primary energy used in the country. Others including renewable energy sources such as
solar, wind, geothermal, hydropower and biogas account for about 1% of the total
energy consumed in Tanzania (Kabaka and Gwang’ombe, 2007).
Figure 1: Status of Energy Consumption in Tanzania
Source: (MEM, 2003)
2
The generation of electricity in Tanzania is mainly from both hydro and thermal power
plants (Table 1). The total installed capacity on the interconnected grid is about 1252
MW of which 562 MW (45%) is hydro and the rest is thermal (URT, 2008). The
Tanzania Electric Supply Company Limited is responsible for the generation,
transmission, distribution and the selling of electricity in mainland Tanzania and also
sells bulk power to Zanzibar where it is distributed to consumers via a local state owned
distribution company (ZESCO).
Table 1: Existing electric power plant generation in Tanzania – interconnected
system Plant Name Fuel Type Units Size -
MW Installed Capacity - MW
Available Capacity - MW
Kidatu Hydro 4 51 204 200
Kihansi Hydro 3 60 180 180
Mtera Hydro 2 40 80 80
New Pangani Falls Hydro 2 34 68 66
Hale Hydro 2 10.5 21 10.5
Nyumba ya Mungu Hydro 2 4 8 8
Uwemba Hydro 1 0.84 0.84 0.76
Total Hydro 562 545
SONGAS I Gas 2 21 42 38
SONGAS II Gas 3 40 120 110
SONGAS III Gas 1 40 40 37
TEGETA_IPTL HFO 10 10 103 100
UBUNGO_T Gas 10 10 102 100
UBUNGO_D IDO 1 34 34 10
ZUZU_D IDO 1 7 7 6.7
IYUNGA_D IDO 1 14 14 12.51
TABORA_D IDO 1 10 10 9.18
NYAKATO_D IDO 1 13 13 11
NJOMBE_D IDO 1 1.3 1.3 1
3
DOWANS I Gas 1 35 35 31.5
DOWANS II Gas 4 20 80 71
AGGREKO Gas 44 1 44 40
ALSTOM HFO 44 1 44 40
Total Thermal 690 618.5
Grand Total 1252 1163.5
Source: URT- Power System Master Plan Study Final report Volume ii - Main Report September 2008
Hydro power plants convert potential energy which is contained in falling water into
electricity. Generation from the hydropower plants is dependent on flow of water in the
river which, undesirably, is stochastic in nature, exhibiting spatial variability as well as
temporal variations (daily, seasonal, annual and over-year variations).
The basic principle of hydro power is that if water is released from a higher level to a
lower level, then the resulting potential energy of water is be used to do work (Mtalo et.
al. 2007).The water head is used to move a mechanical component, which converts the
potential energy of the water into mechanical energy. Hydro turbines convert water
pressure into mechanical shaft power, which can be used to drive a generator
(Mohibullah. et al.2004). Hydro power is a very clean source of energy and only uses
water, the water after generating electrical power, is available for other purposes. Hydro
power is currently the world's largest renewable source of electricity. Hydropower
constitutes 21% of the world’s electricity generating capacity. The theoretical potential
of worldwide hydropower is 2,800 GW, about four times greater than the 723 GW that
has been exploited (e-RGNepal, 2007).
4
Small hydro power plant (SHP) is a scheme with installed capacity of up to 10 MW
(ESHA, 2004). Not only small hydro is a non-polluting energy source, but also it is
much more efficient than the burning of fossil fuels for electricity generation. In respect
to coal burning, the most common energy source, small hydro power is greatly more
efficient. Efficiency of small hydro units range 60% to 90% while modern coal burning
units are 43% to 60% efficient (Wazed and Ahmed, 2008). The best geographical areas
for exploiting small-scale hydro power are those where there are steep rivers flowing all
year round, for example, the hill areas of countries with high year-round rainfall, or the
great mountain ranges and their foothills.
To assess the suitability of a potential site, the hydrology of the site needs to be known
and a site survey carried out, to determine actual flow and head data. In Tanzania small
hydropower potential is estimated at 300 MW with total installed capacity of 4.0 MW
(Karekezi, et.al, 2005). Figure 2 shows small hydro power potential sites of Tanzania.
Small-scale hydropower is one of the most cost-effective and reliable energy sources to
be considered for providing clean electricity generation. In particular, the key
advantages that small hydropower has over other renewable energy sources, i.e. wind,
wave and solar power are: no submergence, no need for environmental clearance,
gestation period is very low, less capital investment, less operation and maintenance
cost, it is a renewable source of energy free from any major environment impact and
creates small nodes of development of the area with lower transmission cost.
5
Legend:
General location of the small hydro potential sites in Tanzania. N.B. Size of the
sphere represents relative number of sites in the region.
River Figure 2: Tanzania map showing small hydropower sites concentrations.
Source: NBCBN (2005)
According to Klunne (2010) key barriers hindering the development of SHP in Africa
can be summarized as follows: Lack of infrastructure for the design and manufacture of
turbines, installation and operation; Difficulty of access to appropriate technologies pico,
micro, mini and small hydropower; Absence of local capacity (local skills and know
how) in developing SHP projects ; Lack of information about potential sites
(hydrological data); Lack of SHP awareness, incentives and motivation; Lack of private
sector participation in SHP development; and Lack of joint venture (public and private
sector partnership). International hydropower association IHA (2003) has grouped these
6
barriers into economic social and environment aspects. Economic aspects which affected
by High upfront investment, precipitation dependent, decreased storage capacity due to
sedimentation, long-term planning requirement and agreement and often requires foreign
contractors and funding. In social aspect these barriers involve: resettlement,
modification of local land use pattern, requirement of management of completing water
use, addressing effect of impacted people’s live hood. Environmentally these barriers are
in the following: Inundation of hydrological regime; modification of aquatic habitats;
water quality, species activities and sediment composition and transport needs to be
monitored.
Africa has one of the lowest hydropower utilization rates. Currently less than 7 % of the
potential has been harnessed (Klunne, 2010). Small hydrower can adequately contribute
to the electricity needs of African countries. Currently the installed capacity of SHP in
Africa is 228MW which is only 0.5% of the total world installed (US DOE, 2004).
1.2 General description of the study area Kilondo Village is located in Ludewa District, Iringa region in the Southern western part
of United Republic of Tanzania (Figure 3). It’s about 100 km from Ludewa town with a
rough road through mountainous areas and Lake Nyasa. The population of the village is
1130 people with 330 households scattered with one primary school, one dispensary and
five small shops at the trading center and two grain mills.
7
Figure 3: Map of Ludewa District showing Location of Kilondo Village/Catchment
8
The main economic activity of the people is fishing and Agriculture (Fig 6(a), a, b, c, d).
The village has never been electrified. Currently, the main sources of energy at Kilondo
village are: firewood, charcoal, kerosene, dry cells, car batteries and a few with
photovoltaic systems. The identifiable and underutilized sources of energy are Solar and
Hydro power from Kilondo river located at 09o 44.545”South 034o 18.7”East. The
village is bounded by Nkiwe village at the Western side, Lumbira village at the Northern
part, Lake Nyasa at the Eastern side and Ifungu village to the Southern part. This village
is located in a mountainous slopes area where it is linked with many rivers which drains
their water into Lake Nyasa. The area is in tropical Savannah climate where it has two
distinct seasons that is rainy and dry seasons. The rainy season begins in January and
ends in June, where dry seasons starts in July and ends in December when rainy starts
again. Kilondo experiences a maximum of rainfall of 150 mm and 2.68 mm minimum.
Temperature recorded at Kilondo between 8°and 25° C, where 8° is minimum and 25
maximum. Kilondo River is a perennial stream with a minimum and maximum monthly
run of 15mm3/s and 164.9mm3/s respectively.
9
Figure 4: A monthly hydrograph for Kilondo River
Source: Author (2010)
Figure 5: Nyasa Basin Hydrometeorogical gauging stations
Source: (URT, 2010)
10
1.2.1 Social economic activities of Kilondo Village
People living at Kilondo Village are Kisi by tribe and they rely largely on fishing and
cultivation of cassava (Fig.6) Their major source of income is fishing on the Lake
Nyasa. Lake Nyasa has variety of different types of fishes. At Kilondo fishing is done by
men only. It is not possible for women to be involved in fishing activities; they believe
that if a woman fishes the lake will not yield more fish catches. Women of Kilondo are
involved in alternative business such as making pots. Women make pots for their own
domestic use and for sale for cash or bartered for food. Cassava is the main staple food
of Kilondo people; it is processed into flour so that it can be used for making stiff
porridge “ugali” which is the staple food in the area.
11
Figure 6(a) Fish drying at Kilondo Figure 6(c) Cassava farm at Kilondo
Figure 6 (c) Pots manufactured in Figure 6 (d) Fishing net preparation
Kilondo Village
Figure 6: Economic activities of Kilondo people
Source: Author (2010)
12
1.3 Statement of the Problem Electricity is one of the vital ingredients of socio-economic development of modern
society (Abosedra, et al.2009). Energy is a prime mover of development. There is direct
correlation of energy consumption and economic growth of a society or country. Access
to modern energy services is fundamental to fulfilling basic social needs, driving
economic growth and fueling human development. This is because energy services have
an effect on productivity, health, education, safe water and communication services.
Modern services such as electricity, natural gas, modern cooking fuel and mechanical
power are necessary for improved health and education, better access to information and
agricultural productivity. Tanzania has average per capital electricity consumption of
Energy 85 Kwh per annum which is low in comparison to 432Kwh and 2176Kwh for
Sub-Saharan Africa and the world average for year 2000(Kabaka and
Gwang’ombe,2007 as quoted in World Bank,2003). Eighty percent of Tanzanian
population lives in rural areas. Where two percent of rural population has access to
electricity (MEM, 2003).
The remoteness of Kilondo Village and its topography makes it difficult to be connected
the electricity the grid. Grid expansion to Kilondo village is not expected in the near
future and therefore decentralized stand alone power plant turbo-generators can
therefore make a sustainable solution for Kilondo village electrification. Therefore, an
exploration of sustainable small hydro energy source that can be maintained in a
decentralized approach, and that the poor can afford, is urgently needed. The absence of
reliable source of energy hinders economic development and provision of social services
13
of Kilondo people. Kilondo village has ungauged river which is considered to have a
potential of producing electricity. The electrical energy in the river has not been utilized
and is lost. Inadequate hydrological information and load demand analysis are the
problems which faces the implementation of a sustainable small hydro power plant
project at ungauged site such as Kilondo River. In this research study the above
mentioned problem would be addressed to develop an affordable, locally serviceable,
off-the-grid generating unit that will provide electricity at the village scale with minimal
environmental impact. It should be easy to implement unit in low-head, variable flow,
high erosion rivers using locally available technologies.
1.4 Objective of the Research
The objectives of the study are divided into general objective and specific objectives.
1.4.1 Main Objective
Main objective of the research study is to propose a sustainable small hydro power for
rural setting.
1.4.2 Specific Objective
The specific objectives of this research are:
1. To assess electricity demand of Kilondo village
2. To estimate head and stream flow of the river suitable for covering this demand.
3. To conduct preliminary design of a small hydro power plant.
4. To conduct environmental, social and economical appraisals of the village.
14
1.5 Research Questions
The following are research questions to be answered at the end of the study:
1. What is status of energy demand in Kilondo Village?
2. What is the status of stream flow regime in Kilondo River?
3. How many potential sites are there in Kilondo River suitable for installing small
hydro power plant?
4. What is the hydro energy potential of Kilondo rivers
5. What is the suitable and affordable design of small hydro power plant for rural
setting, Kilondo village?
6. Which other villages can be served?
7. What other uses can this energy resource cover?
1.6 Expected output
i. The stream flow regime of Kilondo River Hydrograph and Flow duration curve
ii. A number of potential alternative sites suitable for installing small hydro power
plant and their output (each and total)
iii. Energy demand of Kilondo village and a rough estimate of demand in other area
nearby.
iv. Proposed preliminary design of SHP for rural setting of Kilondo village
1.7 Significance of the Study
This study aims at evaluating the small hydropower potential for rural setting. Lack of
adequate source of electrical energy in rural area is a serious problem which hinders the
15
development of rural areas. The study has a number of significant aspects. It is
significant in the following ways:
1. The study aims at contributing ideas on the existing knowledge on the subject
and unfolding the unknown in the subject matter.
2. The research findings will help those who are concerned with the development
of small hydropower plants, as it is stipulated in the energy policy with respect
to the rural energy(energy policy, 2003)
3. No research has so far been carried out in Kilondo (Ludewa) concerning
evaluation of small hydropower potentials. This research intends to give useful
information on development of small hydropower in similar setting in Tanzania.
4. Guidelines developed will be used for other SHP sites in Tanzania.
5. This research will form a basis for the development of SHP technology in
Tanzania.
1.8 Scope of the Study It is limited to rural setting of Kilondo village as the case study. The study does not
cover detail design of the hydropower machines and civil works using rigorous analysis.
The economic analysis is based on preliminary design concept.
1.9 Organization of the Study
This dissertation report has been done through following sequence of steps: Literature
review; Experimental set up; Data collection; Testing the collected data in the
RETScreen module software; and Dissertation report writing.
16
CHAPTER TWO
LITERATURE REVIEW
2.1 Sustainable Energy Sustainable energy is the provision of energy such that it meets the needs of the present
without compromising the ability of future generations to meet their needs. Sustainable
energy sources are most often regarded as including all renewable sources, such as
hydro power biofuels, solar power, wind power, wave power, geothermal power and
tidal power. International Hydropower Association (IHA, 2004) has produced a set of
Sustainability Guidelines which are based on economic, social and environmental
aspects. Sustainable development requires the integration of three components:
economic development, social development and environmental protection as
interdependent, mutually reinforcing pillars.
2.2 Renewable Energy Renewable energy is from an energy resource that is replaced by a natural process at a
rate that is equal to or faster than the rate at which that resource is being consumed.
Renewable energy can come from a variety of sources. Renewable energy generally
means solar, wind, water, wood or other biomass source of energy and geothermal
energy. Hydro power one form of renewable energy since it is naturally replenished.
Hydropower is a key component of renewable energy, and supports protection against
climate change (Seeger,et al, 2010). Figure 7 below shows the hydrological movement
which is the continuous movement of water on, above and below the surface of the
17
Earth. Hydropower uses the energy of flowing water, without depleting it, to produce
electricity; therefore, all hydropower projects – small or large, run-of-river or storage –
meet the definition of renewable energy resource.
Figure 7: Hydrologic Cycle
(Source: http://www.google.co.tz/imgres?imgurl=http://northwestplumbingtampa.com)
2.3 Hydropower Development Hydropower is the production of mechanical energy by passing water through a
hydraulic machine that is rotated by the action of water and the machine in turns rotates
an electrical generator to produce electrical energy (Wazed and Ahmed, 2008). In hydro
power, the kinetic energy of the water depends on two aspects, head and flow. The head
refers to the vertical distance the water travels and the flow refers to the volume of the
water that passes through in the given amount of time (Fig.8). Hydropower plant can be
classified according to the power they produce into the following large, medium, small,
mini, micro and pico.
18
Figure 8: Hydropower plant system
Source: Fritz.J.J (1984)
2.3.1 Small hydro power plant overview
There is no consensus definition on small hydro power plants. Some countries accept 10
MW as the upper limit for installed capacity (ESHA, 2004). For the sake of this research
small hydro power plant is any scheme which has a capacity of generating electrical
energy up to 10 MW. Small hydropower schemes combine the advantages of large
hydro on the one hand and a decentralized power supply, on the other hand. They do not
have many of the disadvantages, such as environmental issues high cost of investment as
in the case of large hydro power plant. Moreover, the harnessing of small hydro-
resources, being of a decentralized nature, lends itself to decentralized utilization. Local
implementation and management, making rural development possible basing on
entrepreneurship and the use of natural, local resources. Small hydro power plants can
be connected to national electricity grid. Most of them are run-of-river type; they do not
19
have any sizeable reservoir and produce electricity when water provided by the river
flow is available, when the river dries up generation ceases. The Efficiency of small
hydro units range from 60% to 90% while modern coal burning thermal power stations
are 43% to 60% efficient (Wazed and Ahmed, 2008)
2.3.2 Large Hydropower plant overview Large hydropower stations are those which have installed capacity of more than
100MW. These stations store large amount of water by using dams (Seeger,et al, 2010).
2.4 Rural areas The term “rural area” refers to a physical location outside of areas that are
administratively managed by urban authorities. Rural areas are relatively far deprived in
terms of modern energy infrastructure.. Rural areas are sparsely settled places away
from the influence of large cities and towns. Such areas are distinct from the more
intensively settled urban areas (Maleko, 2005). Kilondo is one of the rural area in
Tanzania it is isolated; it can be accessed by using Lake Nyasa only. At Kilondo there is
no modern energy infrastructure like electricity and water pump. People of Kilondo use
firewood for cooking and kerosene lamp for lighting.
2.4.1 Effects of rural electrification Rural electrification is important for the sake of retaining people in rural areas.
Electrification is needed to secure the living standard and create opportunities for jobs.
There many environmental, economic, and social effects of rural electrification, some
are positive and others are negative. Environmental effects of rural electrification
20
include: Limit to the contribution to the green house effect, prevents deforestation, limits
pollution, and uses less of the world’s limited resources. Economically rural
electrification has the following effects: – Stops the mitigation of poverty belts, allows
commercial and industrial activities, causes an increased efficiency of agriculture.
Socially there are both positive and negative effects which are: – allows more education,
allows entertainment, improves safety and political stability, Allows medical treatment
and supply of clean water, creates more personal safety problems, encourages more
alcohol use, Allows longer working hours, Encourages prostitution, Causes bad
influences of movies and allows an increase of living standard. These items are some
examples of various effects that can be expected as a result of electrification. Naturally
the effects depend on local conditions and not all of the effects can be expected
everywhere (Ehnberg, 2007).
2.5 Significance of small hydro power plant Hydro power plant has the following significance: suitable resources; diversified energy
supply options; cost of generation of electricity is low; short planning and development
period; SHP projects have lower impacts to environment; it can be implemented and is
affordable for small developers; electrification of rural areas and remote areas; grid
stability , building SHP plants help create a more diversified electricity system,
providing production of electricity in smaller distribution systems when the main grid is
disrupted; rural residential lighting & ICT (isolated or mini grid) ; and rural industrial
and agricultural power supply.
21
2.6 Components of Small Hydro power plants Small run-of-the-river hydropower systems consist of the following basic components.
Fig 9 (Boustani, 2009) :Small diversion dam ; water conveyance channel ; fore bay ;
pipeline, or pressurized pipeline (penstock); turbine transforms the energy of flowing
water into rotational energy; alternator or generator transforms the rotational energy into
electricity; regulator controls the generator - wiring delivers the electricity; tail race;
power house ; and switchyard.
Figure 9: Layout of a typical small hydro scheme
Source: (Boustani, 2009)
2.7 Types of Hydro-Electric Schemes There are three types of hydropower plants which are impoundment, diversion, and
pumped storage.
22
2.7.1 Diversion schemes
These plants use little, if any, stored water to provide water flow through the turbines.
Although some plants store a day or week's worth of water, weather changes especially
seasonal changes cause run-of-river plants to experience significant fluctuations in
power output. The schemes do not include any significant water storage, and therefore
make use of whatever water is flowing in the river.
2.7.2 Storage schemes
Hydro schemes may also be based on the construction of a large dam to store water and
to provide sufficient head for the turbine. Schemes have enough storage capacity to off-
set seasonal fluctuations in water flow and provide a constant supply of electricity
throughout the year. Large dams can store several years’ worth of water.
2.7.3 Pumped Storage Pumped storage hydroelectricity is a type of hydroelectric power generation used by
some power plants for load balancing. The method stores energy in the form of water,
pumped from a lower elevation reservoir to a higher elevation. During periods of high
electrical demand, the stored water is released through turbines.
2.8 Types of Turbines Hydraulic or water turbines are the machines which use the energy of water
(hydropower) and convert into mechanical energy (ESHA, 2004). In general there are
two types of turbines which are: Impulse turbines which comprises of pelton, Turgo and
23
cross flow turbines, and Reaction turbines which comprises of Francis Propeller
,Kaplan and Bulb turbines .
2.8.1 Francis Turbines Francis turbines are reaction turbines with fixed runner blades and adjustable guide
vanes used for medium heads (Fig 10). They can be used for the head from 25 to 350 m
(ESHA, 2004). The Francis turbines may be divided in two groups; horizontal and
vertical shaft. In practice turbines with comparatively small dimensions are arranged
with horizontal shaft, while larger turbines have vertical shaft. Francis turbines can
either be volute-cased or open-flume machines. The spiral casing is tapered to distribute
water uniformly around the entire perimeter of the runner and the guide vanes feed the
water into the runner at the correct angle. The Francis turbine is generally fitted with
adjustable guide vanes. The runner blades are profiled in a complex manner and direct
the water so that it exits axially from the centre of the runner. In doing so the water
imparts most of its pressure energy to the runner before leaving the turbine via a draft
tube
24
Figure 10: Francis Turbine Sourced: www.tfd.chalmers.se/.../phdproject/proright.html
2.9 Turbine Selection The following factors are considered when selecting a turbine : Head and discharge,
Specific speed, Variation of head, Maximum efficiency, Part load efficiency, Initial cost
of civil works, No. of units,. Running and maintenance cost and Cavitation
characteristics (Fig.11).
Draft Tube
Spiral Casing
TurbineRunner
25
Figure 11: Turbine Selection Chart
Source: ESHA (2004)
2.10 Suitable Condition for Small Hydro Power Plants The best geographical areas for exploiting small-scale hydro power plants are those
where there are steep rivers flowing all year round, for example, the hill areas of
countries with high year-round rainfall, or the great mountain ranges and their foothills
(Kabaka and Gwang’ombe, 2007).
26
2.11 Hydro Power Generation
2.11.1 Conversion of Water Power to Electricity The hydro electric plants work by converting the kinetic energy from water falling into
electric energy. This is achieved from water powering a turbine, and using the rotation
movement to transfer energy through a shaft to an electric generator (Fig12).
Hydroelectricity eliminates the flue gas emissions from fossil fuel combustion, including
pollutants such as sulfur dioxide, nitric oxide, carbon monoxide, dust, and mercury in
the coal. Compared to the nuclear power plant, hydroelectricity generates no nuclear
waste, nor nuclear leaks.
Figure. 12: Hydraulic turbine and electrical generator
Source: http://en.wikipedia.org/wiki/Hydroelectricity.(2010)
2.11.2 Preliminary power and energy calculation The amount of energy that can be produced at a site is directly proportional to the
amount of water (flow) and the difference in elevation between the impoundment
27
surface and the turbine (head). A simple calculation using the “power equation” allows
one to estimate the amount of energy that can be produced at an assumed design flow
P = ηρgQoH ……………………………………………………………………….(01)
Where:
η = hydraulic efficiency of turbine;
ρ = density of water (kg/m3);
g = acceleration due to gravity (m/s2);
Qo = Design flow (m3/s);
H = Head – effective pressure of water flowing into the turbine (m) (net head); and
P = Electrical power (w).
2.11.3 Design Flow It is not promising to have a scheme that uses significantly more than the mean river
flow (Qmean) since it will not be environmentally acceptable or economically attractive.
Therefore the turbine design flow for a run-of river scheme (a scheme operating with no
appreciable water storage) will not normally be greater than Qmean. The greater the
chosen value of the design flow, the smaller proportion of the year that the system will
be operating on full power, i.e. it will have a lower ‘Capacity factor’. So in order to have
a full power the design flow should be less than the mean flow.
2.11.4 Capacity Factor The ‘Capacity factor’ is a ratio summarizing how hard a turbine is working, expressed as
follows:
28
Capacity factor (%) = Energy generated per year (kWh/year)……………………..……. (02) Installed capacity (kW) x 8760 hours/year A Table 2 below shows how Capacity factor varies with design flow as given as follows:
Table 2: Variation of capacity factor with design flow Design Flow QO Capacity Factor Qmean 40% 0.75Qmean 50% 0.5 Qmean 60% 0.33 Qmean 70% Source : BILA(2005)
2.11.5 Rated Power The peak power P can be estimated from the design flow Q0 and head H as follows:
P =7xQoxH………………...………………………………………………..……….. (03)
P = Electrical power in (kW);
Qo = Design flow (m3/s); and
H = Head (m)
2.11.6 Energy Output The annual energy output is then estimated using the Capacity Factor (CF) as follows:
E = P xCF x8760…………….………………………………………………………..
(04)
E = Energy (kWh/year)
P = Electrical Power (kW)
8760 = Hours per year
2.12. Stream Flow Estimation Methods
29
Flow rate is the quantity of water available in a stream or river and may vary widely
over the course of a day, week, month and year (Brassington, 1988; Hauer and Lamberti,
1996). Mathematically Stream flow or discharge is the rate at which a volume of water
passes through the cross section of the stream per unit time, and as such has SI units of
cubic meters per second (m3/s) or cumecs. The common methods for measuring stream
flow are: Volumetric, Velocity, Method, Dilution and Floating body method.
2.12.6. Floating Body Method In this method of measuring stream flow, velocity of the stream is measured by using a
floating object. The floating object, which is largely submerged (for instance a wood
plug or a partially filled bottle), is located in the centre of the stream flow (Wazed et.al,
2008). The time t (seconds) elapsed to traverse a certain length L (m) is recorded. The
surface speed (m/s) would be the quotient of the length L and the time t. To estimate the
mean velocity, the above value must be multiplied by a correction factor that may vary
between 0.60 and 0.85 (ESHA, 2004) depending on the watercourse depth, bottom and
riverbank roughness. The accuracy of this method is dependent on the range of
correction factor. Mean flow of the stream is obtained by multiplying the stream flow
velocity and its cross sectional area.
Mean stream flow (m3/s) = Q x A……………………………………………………(05)
Q =Average flow velocity (m/s)
A = Cross sectional area (m2)
30
Figure 13 below shows how to determine the cross sectional area of the stream. Where h
is height at different points, b is a stream width and s is the cross sectional area.
Figure 13: Measuring the cross-sectional area
Source. ESHA (2004)
The following materials are needed in this method: copies of stream flow calculation
sheet; stop watch; meter stick; waders; long tape measure; and oranges.
2.13. Hydrological data analysis Hydrology is the science that encompasses the occurrence, distribution, movement and
properties of the waters of the earth and their relationship with the environment within
each phase of the hydrologic cycle. Surface hydrology: Related to movement of
water over the ground surface includes both overland flow and stream flow.
2.13.1Rating curve
31
Rating curve is a graph of discharge versus stage for a given point on a stream, usually
at gauging stations, where the stream discharge is measured across the stream channel
with a flow meter. Numerous measurements of stream discharge are made over a range
of stream stages. The rating curve is usually plotted as stage on x-axis versus discharge
on y-axis (Herschy, 1999).
: Figure 14: Rating Curve Source(ESHA,2004)
In order to develop a rating curve two procedures have to be followed, first the
relationship between stage and discharge is established by measuring the stage and
corresponding discharge in the river. Second stage of river is measured and discharge is
calculated by using the relationship established in the first part. Stage is measured by
reading a gauge installed in the river. If G represents stage for discharge Q, then the
relationship between G and Q is expressed by a single valued equation (Herschy, 1999)
Q = ( )βaGCr − ............................................................................................................ (06)
32
Where Cr and β are rating curve constants ‘a’ is a constant which represents the gauge
reading corresponding to zero discharge.
2.13.2 Flow Duration Curve A flow duration curve (FDC) is a graphical plot of daily stream flow versus the percent
of days that the stream flow value is exceeded. FDC provides a probabilistic description
of stream flow at a given location. A flow duration curve relates flow values to the
percent of time those values have been met or exceeded. The FDC is used to assess the
expected availability of flow over time and the power and energy at a site and to decide
on the “design flow” in order to select the turbine. If a system is to be independent of
any other energy or utility backup, the design flow should be the flow that is available
95 percent of the time or more (Arora, 1996).
2.13.3 Load duration curve
Load duration curve (LDC) shows the cumulative frequency distribution of the system
load. It represents graphically how much energy is supplied to the various levels of the
system load. The distribution of the loads as shown by load duration curves gives the
planner vital information for determining the proper mix of base, intermediate, and peak
capacity. It also helps to determine the cost of the facility to meet load demands (Jalal,
1999). A power duration curve is plotted between the power as ordinate and the
percentage of time at a particular amount of power is equaled or exceeded as abscissa.
33
2.14 Environmental Impact Assessment (EIA) Environmental impact assessment is defined as a process of identifying, predicting,
evaluating and mitigating the biophysical, social, and other relevant effects of
development proposals prior to major decisions being taken and commitments made
(IAIA, 1994). The following issues are considered in evaluating environmental impact
assessment for hydro power development: Water quality, sediment transport and
erosion, Downstream hydrology and environmental flows, Rare and endangered species,
passage of fish species, pest species within the reservoir (flora & fauna), Health issues,
Construction activities and Environmental management systems.
2.15. Social Impact Assessment (SIA) Social impact assessment is a process of analysing, predicting and evaluating the future
social and economic effects of proposed policy, program and project decisions and
actions on the well-being of people, and their businesses, institutions and communities.
Its goal is to protect and enhance the quality of life by ensuring that potential socio-
economic impacts are minimized and sound environmental decisions are made
(Stevenson, 1994). Social impacts means the consequences to human populations of
any public or private actions-that alter the ways in which people live, work, play, relate
to one another, organize to meet their needs and generally cope as members of society.
The term also includes cultural impacts involving changes to the norms, values, and
beliefs that guide and rationalize their cognition of themselves and their society (Burdge
et al.2003).
34
2.16. Electrical Demand Analysis Demand forecasting, can be described as the science and art of specification, estimation,
testing and evaluation of models of economic processes’ that drive the demand for fuels.
For the power evaluation knowledge of power requirement of nearby populations are
necessary. The following factors are considered during the electrical load survey of
nearby villages up to 4 to 10 km distance from the location of proposed SHP station
(Singh, 2006): Number of villages; No. of houses; Population; No. of projected
connections; Average energy consumptions; Demand for street lighting; No. of
commercial establishment and energy demand for each establishment; No. of schools,
health centers and other community services and their energy demand; No. of small
industries with energy requirement for each; Miscellaneous demand; and Current and
projected demand for electrical energy of various types of consumption
According to (Mehra, 2001), rural electricity demand can be estimated by using the
following methods: trend method, end use method (field survey), and econometric
approach method.
2.16.1 Trend analysis Trend analysis extends past rates of electricity demand in to the future. Trend analysis
focuses on past changes or movements in electricity demand and uses them to predict
future changes in electricity demand (Ghods and Kalantar, 2008).
12.16.2 End use approach method The end-use approach directly estimates energy consumption by using extensive
information on end users, such as applications, the customer use, their age, sizes of
35
houses, and so on. Statistical information about customers along with dynamics of
change is the basis for the forecast. The end –use models for electricity demand focus on
its various uses in the residential, commercial, agriculture and industrial sectors of
economy. The following relation defines the end use methodology for a sector :(
Equation 07)
E = S x N x P x H…………………………………………………………….. (07)
E = energy consumption of an appliance in kWh
S = penetration level in terms of number of such appliances per customer
N = number of customers
P = power required by the appliance in kW
H = hours of appliance use (Mehra, 2001).
This, when summed over different end-uses in a sector, gives the aggregate energy
demand.
2.16.3 Econometric approach method The econometric approach combines economic theory and statistical techniques for
forecasting electricity demand. The approach estimates the relationship between energy
consumption (dependent variables) and factors influencing consumption. The
relationships are estimated by the least square method or time series methods. The
following relation defines econometric approach (Equation 08)
ED = f (Y, Pi, Pj, POP, T)……………………………………………………. (08)
Where,
36
ED = electricity demand; Y = output or income; Pi = own price;
Pj = price of related fuels; POP = population; and T = technology;
2.16.4 Load and Energy Forecast A 25 years load forecast is the recommended planning period by TANESCO for areas to
be supplied through grid extension, owing to the time lag for house wiring and extension
of service lines to customers, the anticipated load cannot be reached in the 1st year.
Future annual peak demand and energy is estimated using historical growth rates used
for similar electrified areas as follows;
• In the first four years after commissioning of the project, load will be expected to
grow by 25% annually to the initial full load.
• From the fifth year onwards, the loads for each tariff category will grow
according to the following rates:
4% for the residential consumers
3% for commercial consumers
2% for light industrial and
2% for public lighting
These are measures of divergence of spreading over time of the peak loads. Three
diversity factors namely, unit diversity factor (g1), Group diversity factor (g2) and
overall diversity factor (g3)
Diversity factors-These permits computation of combined peak loads of individual,
group and combination of group in terms of disaggregate peak values. For each type of
consumer, two type of diversity are applied to the maximum installed load in order to
obtain maximum demand
37
Unity diversity factors (g1)-This is applied to the maximum installed load of unit (e.g.
one medium size residential house) on account of the fact that not all the loads in a unit
shall be operational at any one instant. This is ranged from 0.25 to 0.8 depending on the
nature of the consumer.
Group diversity factor (g2) -This is applied to the total maximum installed loads for a
given type on account of the fact that not all the units within a load type would be
simultaneously in operation this ranges between 0.6 to 1
The overall diversity factor (g3)- This was applied on account of the fact that not all the
consumers in a particular category shall be simultaneously connected the values of 0.5
taken for this factor.
TANESCO’S standard values of diversified unit load and group diversity factor for
classified loads are summarized as is appendix A.
2.17 Economical Appraisal Economic analysis is a comparison of costs and benefits that enables the
investor/investors to make an informed choice whether to develop the project or
abandon it. It is also possible that a choice may be made between different hydro
projects so that the investment can be made in the one that gives the best return (ESHA,
2004). Hydro power projects can be considered as a tool for economic development, due
to its longevity, favorable energy payback periods, their pivoted role in integrated
energy systems and their multi-purpose character. Economic aspects which are
considered in sustainable hydro power plants are: Distribution and sharing of benefits,
38
Demonstrated need, Cost-benefit and economic performance, Longevity of benefit,
Local capacity building and Resource use.
2.18. RET Screen Model RET Screen is a computer model developed by the Government of Canada, Department
of Natural Resources and available freely over the internet at www.retscreen.net. The
model is available in several languages. The purpose of the model is to evaluate the
following: Energy production, life cycle cost and greenhouse gas (GHG) emission
reductions. Currently, the software can be used to evaluate eight technologies which are:
small hydro, wind energy Photovoltaic, solar air heating, biomass heating, solar water
heating, passive solar heating and ground-source heat pumps.
2.18.1 RET Screen Small Hydro Project Module The RETScreen small hydro project module provides a means to assess the available
energy at a potential small hydro site that could be provided to a central grid or, for
isolated loads, the portion of this available energy that could be harnessed by a local
electricity utility. Seven worksheets: Energy Model, Hydrology Analysis & Load
Calculation, Equipment Data, Cost Analysis, Greenhouse Gas Emission Reduction
Analysis, Financial Summary, and Sensitivity & Risk Analysis are provided in the small
hydro project workbook file. The Energy Model, Hydrology & Load and Equipment
Data worksheets are completed first. The Cost Analysis worksheet should then be
completed, followed by the Financial Summary worksheet. The GHG Analysis and
39
Sensitivity worksheets are optional analyses. Various algorithms are used to calculate,
on an annual basis, the energy production of small hydro power plants in RETScreen.
User inputs include the flow-duration curve and, for isolated-grids, the load-duration
curve. Turbine efficiency is calculated at regular intervals on the flow-duration curve.
Plant capacity is then calculated and the power-duration curve is established. Available
energy is simply calculated by integrating the power-duration curve. In the case of a
central-grid, the energy delivered is equal to the energy available. In the case of an
isolated-grid, the procedure is slightly more complicated and involves both the power-
duration curve and the load-duration curve.
2.18. 3 Benefit of RET Screen Small Hydro Project Model
The principal benefit of RETScreen model is that it requires a relatively small amount of
input data to run annual or monthly data compared to hourly data for competing
simulation models.
2.18.4 Limitation of RET Screen Small Hydro Project Model There are some limitations associated with the Small Hydro Project Model. First, the
model has been designed primarily to evaluate run-of-river small hydro projects. The
evaluation of storage projects is possible; however, a number of assumptions are
required. Variations in gross head due to changes in reservoir water level cannot be
simulated. The model requires a single value for gross head and, in the case of reservoir
projects; an appropriate average value must be entered. The determination of the average
head must be done outside of the model and will require an understanding of the effects
40
of variations in head on annual energy production. Alternatively simulations can be
made using maximum and minimum head values. Second, for isolated-grid and off-grid
applications in isolated areas, the energy demand has been assumed to follow the same
pattern for every day of the year.
41
CHAPTER THREE
METHODS AND MATERIALS The methodology adapted in this study entailed the following activities: Data collection
(primary and secondary data); data analysis etc.
3.1. Data Collection Design of a hydropower scheme requires the collection of a substantial data base. Data
required may be classified into the following categories: Hydrology, Sediments, Power
market survey, Topographic survey, Geology, Constructional material and socio-
economic survey.
3.1.1 Preliminary Studies
Collection and review of all available and pertinent documents. Air photo or GIS
interpretation was employed to assess site features. Collection of secondary data on
various aspects including geography and demographic characteristics, renewable energy
technology was done through visiting Ministry of land and Human Settlement, Ministry
of water and Irrigation , Tanzania metrological Agency , National website and local
government (extension office). The secondary data were collected through a review of
published and unpublished literature. The review was also done in books, journal,
articles, research reports, thesis reports both for PhD and Masters, conference
proceedings and electronic materials.
3.1.2 Reconnaissance Survey
The purpose of a site reconnaissance visit is to gain an understanding of site
characteristics, potential problems as well as solutions, and input to the site selection of
42
the main project structures. The site visit provides an opportunity to obtain an
appreciation of site topography, flow regime, geology and access for roads and
transmission lines. From these on-site observations it is often possible to identify
practical locations for temporary facilities, head-works, desilting tank and power house
and then to decide the side of the river best suited routes.
3.1.3 Detail Site Investigations
Detail site investigation comprises the following activities: topographic survey,
geotechnical investigation and constructional material search.
3.1.4 Primary data and secondary data
Both primary and secondary data were gathered. Primary data were collected from the
field these are hydrologic data, topographical data and geological data, while secondary
data collected from existing information available in reports and documents to
supplement field data.
3.2 Preliminary Electricity Demand Assessment In estimating preliminary electrical energy demand end use method or field survey was
used. A questionnaire which consists of a list of more or less sophisticated questions
that are put to existing potential consumers was provided and filled. All various type of
potential consumers at Kilondo Village was determined through physical counting and
categorized as domestic consumers (small, medium and large), commercial consumers
(shops, hotels, etc), light industries and others. Estimates for the number of domestic
consumers in the study area are based on the number of permanent houses which satisfy
the utility (TANESCO) standards for electrification. Further, the quality and size of the
43
house was taken into account to enable grouping into small, medium and large
categories.
3.3 Identify potential hydro power sites. Adequate head and flow are necessary requirements for hydro power generation.
Consequently these parameters are important factors in site selection. The gross head may
be estimated, either by field surveying or by using a GPS (Global Positioning System) or by
orthophotographic techniques (ESHA, 2004). However Spatial Data were used for
identifying the potential sites. The data under this category include; the Arcview GIS
DEM of the Kilondo catchment. Also the land cover/land use and soil maps of the area
were used to determine the area and hydrologic parameters suitable for hydropower
installation.
3.4 Estimate stream flow of the River. Measured hydrological flow data or stream gauging information located on the Kilondo
catchment should be utilised. A minimum of 1 year daily flow data is required to make a
preliminary assessment. Since Kilondo site is ungauged its hydrological data does not
exist, flow and rainfall information data for an adjacent (or similar) catchment maybe
used, and adjusted for catchment area and average rainfall level. Given the similar nature
of the topography, mean annual rainfall and catchment areas it would be expected that
the flow duration curves for these catchments would be similar. This provides some
uncertainty in the results, but will be sufficiently accurate for the purpose of a pre-
feasibility assessment.Time series data was used for estimating the stream flow of
44
Kilondo River. The data under this category include monthly data of rainfall, flow.
Rainfall data are used to control the water balance for hydrological modeling. This study
use data recorded between years 1976 through 1985 from Labial gauging station. The
data was collected from the Ministry of Water and irrigation and Tanzania Metrological
Agency. These include, year, month, rainfall and mean annual rainfall. Besides, the
author measured manually the stream flow by using a floating body method, and the
discharge obtained were compared to the data obtained from the ministry in May 2010.
3.5 Hydrological Modeling Confirmation of accurate hydrology and detailed modeling was made to confirm the
flow duration curve by using RETScreen software. A long-term record of flow data and
rainfall, together with an estimation of the compensation/environmental flow (if
required) was assessed. Assessment of seasonal variation and peak and off-peak
demands need to be considered. A firm capacity of the scheme was determined, based
upon the 90th percentile flow from flow duration curve.
3.6 Environmental impact assessment Checklist method was used to annotate the environmental features of factors that need to
be addressed when identifying the impacts of small hydropower plant. There are a
number of environmental considerations that need to be investigated as part of the
feasibility study. These includes reviews and assessments of likely environmental
impacts, broadly considering factors such as: assessment of any planning legislation and
policies for the area, requirements for clearing native vegetation, Impacts on stream flow
45
and fish migration, Inundation or river barrier issues, operational impacts and
construction impacts.
3.7 Social Impact Assessment Based on the stratified simple random sampling technique, some households were
selected for collecting primary data on several household-level parameters through door-
to-door survey of households. Stratification of village on the basis of suburb will be
carried out to collect data from each stratum through a semi-structured questionnaire.
Various sets of information on socio-economic, demographic and housing characteristics
were asked. Questionnaire developed on the basis of the potential for resettlement and
relocation, inundation of arable land, public safety, inundation of sacred sites/areas of
cultural or historical value, and stakeholder management All the primary data was
coded, double entry was made for data cleaning and validation for further analysis
through SPSS.
3.8 .Preliminary Design of Small Hydro power Plant The design of the scheme should be completed at a level adequate for costing and a bill
of quantities to be determined. Hence, the design should be adequate for tendering
purposes, and would include general arrangement and layout drawings. Prominent
aspects of the works can be categorized into: Design flow rate and gross head;
Preliminary sizing of Civil works (intake and weir, intake channel, penstock;
powerhouse, tailrace channel, site access, construction details and hydraulic losses);
Net head on turbine ; Turbine selection ; Installed capacity ;Key specifications of
46
electromechanical equipment (turbine, generator, and control system); Network
connection design to allow assessment of the local power distribution and
the community demand requirements and ; and Gross annual or monthly generation,
losses, and net sales to the grid.
3.9 Economic analysis
The economic analysis focuses on social costs and benefits of the proposed project or
investment for the larger social point of view.
A financial analysis will allow the economic viability of the project to be assessed. The
analysis must consider the following parameters as part of its economic modeling: Base
cost estimate; Revenue assessment – the value of energy based upon market analysis or
demand capability. Include seasonal variation and peak/off-peak pricing; Financing
strategy; Cash flow analysis and implementation schedule; and Economic life.
The economic viability was presented by means of the unit cost of energy (Tsh/kWh),
net present value and the internal rate of return. Small hydro costs can be split into four
segments: Machinery, Civil Works, Electrical Works, and External Costs (BILA, 2005).
Machinery cost includes the turbine, gearbox or drive belts, generator and the water inlet
control valve. Civil Works includes the intake, forebay tank and screen, the pipeline or
channel to carry the water to the turbine, the turbine house and machinery foundations,
and the tailrace channel to return the water to the river. The electrical system will
involve the control panel and control system, the wiring within the turbine house, and a
transformer if required, plus the cost of connection to the electricity. These costs are
largely dependent on the maximum power output of the installation. The connection cost
47
is set by the local electricity distribution company. External Costs encompass the
engineering services of a professional to design and manage the installation, plus the
costs of obtaining the licenses, planning permission, etc.
48
CHAPTER FOUR
DATA COLLECTION AND ANALYSIS
4.1 Data Collection In this research study the following data were collected: Topographical maps, Rainfall
data, Hydrological data, market survey, Socio-economic information and Environmental
impact data.
4.1.1 Rainfall Data The use of rainfall data is essential and fundamental to the rainfall-runoff process. The
accuracy of the rainfall data at a point (i.e., at the rain gauge) is extremely significant to
all the remaining use of the dat. Daily rainfall records have been obtained from the
Tanzania Meteorology Agency and the Ministry of Water and Irrigation.
4.1.2 Hydrologic Data This was collected from the Ministry of Water and Irrigation only hydrological data
for gauged catchments were obtained but for ungauged catchment the empirical method
was used to obtain the data. Kilondo catchment is ungauged, data from Lumbira river
Station, (Long, 9'35''0'''s lat, 34'9'0'' E) (IRC13) were used which is near Kilondo and
they have similar hydrological characteristics. Table 3 shows the mean monthly flow for
Labial River from 1976-1985 as collected from the Ministry of Water and Irrigation.
49
Table 3: Mean Monthly Flow ( m3/s) for Lumbira River from (1976-1985)
Year Jan Feb Mar April May Jun July Aug Sept Oct Nov Dec 1976 38.2 40.7 60.2 87.93 50.6 36.2 29.8 28.4 21.77 19.0 16.6 17.1 1977 24.4 16.2 21.1 40.9 45.4 30.7 27.3 22.9 19.3 17.1 21.5 31.5 1978 56.6 50.6 81.8 58.2 42.1 33.5 29.6 26.0 22.7 19.7 24.3 32.2 1979 40.9 81.4 99.8 117.2 164.9 38.8 29.8 m m m 17.6 25.9 1980 41.1 33.6 41.9 82.5 45.1 28.4 22.8 19.9 17.7 14.6 14.5 24 1981 35.1 51.4 46.4 37.5 41.9 27 21.7 19.0 15.2 13.3 14.7 31.6 1982 29.1 33.6 35.8 52.4 71.9 52.7 45.5 42.9 38.6 34.9 32.4 40.4 1983 43.5 36.7 52.7 65.9 47.6 41.4 36.9 37.9 40.7 37.1 26.6 36.3 1984 67.7 73.2 77.6 62.9 54.8 57.1 56.7 61.3 57.8 51.6 60.3 m 1985 59.1 71.8 92.6 70.5 108.2 80.6 61.8 51.9 42.2 42.9 31.1 66.1 Note: ‘m’ stands for missing data
4.1.3 Drainage area Drainage area for gauged site, Lumbira Catchment was obtained from the given data
from the Ministry of Water and Irrigation, Station Lumbira,( Long, 9'35''0'''s lat, 34'9'0''
E) (IRC13) is 1414 km2
4.1.4 Stream velocity Stream velocity was measured by using floating body method. Measurement was taken
at the place where the axis of the streambed is straight and has constant cross section
area. An orange was tossed from the upstream of the river and the time used to travel the
floating distance was recorded. This sequence was repeated several times at four
different locations from the edge of the river, and average time was obtained, hence
average velocity was cat different location was calculated. Table 4 shows velocity of
stream at various positions.
50
Table 4: Stream Velocities at Different Locations as sampled on May 2010
Location (meters from edge)
Depth (m)
Velocity 1 (m/s)
Velocity 2 (m/s)
Velocity 3 (m/s)
4 1.34 0.831 0.841 0.862 8 1.36 0.955 0.986 0.96 12 1.75 1.041 1.046 1.02 16 1.68 0.887 0.91 0.95 Average Velocity 0.928 0.945 0.948 Mean average 0.94m/s Therefore mean average stream velocity is 0.94 m/s
4.1.5 Cross sectional area of the Kilondo River Measurement of stream flow was made at the place where the axis of streambed is
straight and the cross section of the river is almost uniform. The width of the river was
measured by using a measuring (100m) tape. At this place a width of the river was
approximately 20 meters. Since Kilondo River is very wide a boat was used to assist in
taking measurement as platform (Figure 15).
51
(a) Measuring width of River (b) Recording time of flow for floating body
On 22 May 2010 On 22 May 2010
(c)Measuring length of course of (d) Kilondo River with constant cross section
Stream reach.
Figure 15: Measuring stream velocity and cross sectional area of Kilondo River. Source: Author (2010) Cross section area of the stream was measured by first determining the average depth at
the site as explained in Fig. 13. The sum of depth measurements was determined and it
was divided by the number of depth measurements (intervals) made. Average depth (m)
was calculated. Average depth was multiplied by the stream width to get the cross
52
sectional. Figure 13 shows how to calculate the cross section area of a stream using the
following equation
S= b
+
nhh ....... ……………………………………………………………………..(09)
S= 20
+++
468.175.136.134.1
S = 30.65 m2
The cross sectional flow area of the Kilondo stream calculated was 30.65 m2
4.1.6 Stream Discharge of Kilondo River Stream flow was calculated using the following formula
Stream Discharge (m3/s) = Average Depth x Width x Average Velocity
Stream Discharge (m3/s) = Cross sectional area x mean average velocity
Stream Discharge (m3/s) = 30.65x 0.94
= 28.821 m3/s
4.1.7 Environmental and Social Impact assessment Environmental Impact Assessment (EIA) of Kilondo Hydro power plant project was
done using Rapid Impact Assessment Matrix (RIMA). The results are shown in the
Appendix J of this dissertation report. Social impact analysis was done by survey
method of Kilondo households. Questionnaire was used to collect data for some selected
families. A sample questionnaire is shown in Appendix C and some results of the
outcomes are shown in Appendix I of this dissertation report.
53
4.1.8 Number of identified consumers in Kilondo Village A total number of 348 consumers were identified at Kilondo village which are; small
house 330 consumers, light commercial 14, light industry 2 and other social services 2
(Appendix D).
4.2 Data Analysis
4.2.1 Introduction For estimating stream flows in m3/s a nearby station IRC13 at Lumbira village was used.
Its data for the period from 1976 to 1985 were collected from the Ministry of Water and
Irrigation. These data were used for estimating nearby flows of the Kilondo River which
is ungauged using ratio of area method. Daily rainfall data were obtained from the
Tanzania Meteorological Agency (TMA), while the social and environmental impact
data were obtained at Kilondo village through the questionnaire and interview. Arc view
GIS software was used to delineate the study area and calculating catchment area.
4.2.2 Data preparation The data collected from 1976 to 1985 for daily flows: The following procedures were
used to prepare data for the analysis. Missing daily discharge data were filled using the
daily seasonal mean values .These were obtained from the daily discharge time series by
getting the average for a particular day in a particular month in all the years available,
Average rainfall over the catchment was obtained by using the Arithmetic method,
where the average for a particular day in a month was obtained by averaging values for
that day in the time series from all the rain stations in the catchment.
54
4.2.3 Mean Annual Flow for gauged site The mean annual flow is calculated from the data (1976 – 1985) of flows of Lumbira
(Gauged site) see Table 5 as follows;
The mean monthly flows = ∑ (Mean Daily Flow for each day)…………………(10) Number of Days in a month Mean annual flow for each year (MAF) = ∑ (Mean Monthly Flows for each year)….(11) 12 Mean annual flow for all the year = ∑ (Mean annual flows for each year)…………..(12) 10 years Table 5: Mean annual flow (m3/s) for Lumbira River for the period 1976 to 1985
Year Jan Feb Mar April May Jun July Aug Sept Oct Nov Dec Mean 1976 38.2 40.7 60.2 87.93 50.6 36.2 29.8 28.4 21.77 19.0 16.6 17.1 37.2 1977 24 16 21 40 45 30 27 22 19 17 21 31 26.5 1978 56 50 81 58 42 33 29 26 22 19 24 32 39 1979 40 81 99 117 164 38 29 34 30. 27 17 25 59.0 1980 41. 33. 41. 82 45 28.4 22.8 19.9 17.7 14.6 14.5 24 32.1 1981 35.1 51.4 46.4 37.5 41.9 27 21.7 19.0 15.2 13.3 14.7 31.6 29.5 1982 29.1 33.6 35.8 52.4 71.9 52.7 45.5 42.9 38.6 34.9 32.4 40.4 42.5 1983 43.5 36.7 52.7 65.9 47.6 41.4 36.9 37.9 40.7 37.1 26.6 36.3 41.9 1984 67.7 73.2 77.6 62.9 54.8 57.1 56.7 61.3 57.8 51.6 60.3 33 59.5
1985 59. 71.8 92.6 70.5 108.2 80.6 61.8 51.9 42.2 42.9 31.1 66.1 64.9
AVg 43. 48 60.9 67.6 67.25 42.6 36.2 34.4 30.66 27.8 25.9 33.9
Mean Annual flow(m3/s) 43.3
Hence, The Mean Annual Flows for gauged site is 43.32m3/s
4.3 Flow-duration curve for gauged catchment Flow-Duration Curve of a stream is a graphical plot of stream discharge against the
corresponding percentage of time that the stream discharge was equaled or exceeded.
Preparing a flow-duration curve. In preparing flow duration curve, stream flow data was
arranged in a descending order of stream discharges. As the number of discharges is
55
very large, a range of values as class intervals was established from the available daily
flows data, from the year 1976 to 1985. The obtained class intervals are shown bellow
(Table 6). The plotting position was calculated from Weibull plotting relationship and
the results were plotted on a sheet of logarithmic probability paper Percentage
probability, Pp, of any flow magnitude, Q being equaled or exceeded is given as
Pp = ( )%100*1+N
M………………………………………………………………….(13)
m = the order number of the discharge (or class interval)
N = the number of data points in the list
Table 6: Daily mean discharge and percentage probability Daily Mean Discharge ( m3 /s)
Number of Days the flow in the stream belonged to the class Interval
Tot
al
of
colu
mns
2.
.11
(197
6-19
85)
Cum
ulat
ive
Tot
al (
m)
Pp (%
)
76 77 78 79 80 81 82 83 84 85 1 2 3 4 5 6 7 8 9 10 11 12 13 14 219.99-200 0 0 0 7 0 0 0 0 0 0 7 7 0.19 199.99-180 0 0 0 13 0 0 0 0 0 0 13 20 0.55 179.99-160 0 0 0 8 0 0 0 0 0 0 8 28 0.77 159.99-140 5 0 0 4 0 0 1 0 0 0 10 38 1.04 139.99-120 2 0 0 5 0 0 1 1 0 0 9 47 1.29 119.99-100 4 0 5 19 1 0 0 0 1 41 71 118 3.23 99.99-80 3 0 9 24 12 1 2 2 16 51 120 238 6.51 79.99-60 19 5 48 16 32 7 24 26 140 96 413 651 17.82 59.99-40 88 28 67 36 25 64 160 150 173 148 939 1590 43.5 39.99-20 152 232 211 113 180 178 157 186 31 26 1466 3056 83.6 19.99-00 93 100 25 120 116 115 20 0 5 3 597 3653 99.9 366 365 365 365 366 365 365 365 366 365 N=3653 By using Table 6 FDC of Lumbila gauging station is drawn in the Figure 16.
56
Figure 16: Flows – Duration Curve for Gauged Catchment, Lumbira
Figure17 : Lumbira Catchment delineated using Arcview GIS
57
4.4 Estimating mean annual flow for ungauged catchment
Drainage area at the ungauged river catchment The drainage area for the ungauged was obtained using Arc view GIS 3.2a computer
software (Fig. 18). Digital elevation Model (DEM) of Tanzania was used to delineate
the required area. Catchment Area of 1512 km2 was delineated.
The Ratio of area method was used to find the mean annual flow (MAF) for the
ungauged catchment area using the following relation
MAFungaged = MAFgaged x Aungaged …………………………………………….(14) Gauged
The MAF is 1.069
58
Figure 18: Kilondo Catchment Area delineated using GIS
4.5 Correlation Analysis In this method, it is assumed that gauged points and ungauged points are correlated and
the river flow changes have linear relationships with hydrological parameters of the
water in order to prove the relationship. The correlation analysis was carried out for the
given values of Average monthly flows (m3/s) for Lumbira and Rainfall (mm) for
59
Kilondo Village. Table 7 shows average flows for the two sites, respectively and average
rainfall
Table 7: Average Flows ( m3/s) and Rainfall (mm) Data from 1976 – 1980 Months Average Flows (m3/s) Average Rainfall (mm)
Jan 43.6
120.32
Feb 48.9 125.84
March 60.9 166
Apr 67.9 175.3
May 67.25 150.32
Jun 42.6 114.7
Jul 36.2 18.19
Aug 34.4 2.68
Sept 30.66 2.65
Oct 27.8 1.86
Nov 25.9 89.02
Dec 33.9 114.31
Karl Parsons Coefficient of Correlation, (r) was computed using equqtion 15
……………………………………………………………………(15)
Where x represents monthly average flows for Lumbila river and y represent monthly
rainfall data for Kilondo. Values of r lying between +1 and -1, where +1 indicates
perfect direct correlation,-1 indicates perfect inverse correlation and 0 indicates that no
correlation exists between these values. Generally, a value of r ranges from 0.7 to 1 and -
( )( )∑∑∑=
22 yx
xyr
60
0.7 to -1 show that a fair amount of correlation exists. The Table 8 below shows how
Correlation Analysis was done Average flows for Lumbira( gauged site ) ( m3/s) and
Rainfall (mm) data for Kilondo ( ungauged site ) from 1976 – 1980 .From the Table 7
the value ( r )= 0.9195 that has Mean Monthly flows for Lumbira (gauged site for 1976-
1985) ) ( m3/s),( x ) is highly correlated with respect to Monthly Rainfall (mm) data for
Kilondo ( ungauged site for 1976-1980), ( y).
Table 8: Calculation of Karl Pearson’s coefficient of correlation (r) X Y X2 Y2 X*Y 43.6 120.3 1900.9 14476.9 5245.9 48.9 125.8 2391.2 15835.7 6153.6 60.9 166 3708.8 27556 10109.4 67.9 175.3 4610.4 30730 11902.8 67.3 150.3 4522.5 22596.1 10109 42.6 114.7 1814.8 13156. 4886 36.2 18.2 1310.4 330.8761 658.4 34.4 2.7 1183.4 7.1824 92.1 30.6 2.7 940 7.0225 81.2 27.8 1.9 772.8 3.4596 51.7 25.9 89 670.8 7924.5 2305.6 33.9 114.3 1149.2 13066.7 3875.1 ∑ 24975.4 145690.7 55471.3 r 0.919595319
4.6 Estimating a flow-duration curve for ungauged catchment A flow duration curve for ungauged catchment is estimated by using a curve derived for
a gauged site along the same stream or in a neighbouring catchment. A flow of Kilondo
River was obtained by multiplying the ratio of two catchments and flow of gauged
catchment which is Lumbira (Equation 14).Therefore, multiplying the ordinates-vertical
scale representing flow – of the flow-duration curve for the gauged site by the ratio of
61
the mean annual flow at the ungauged site to that at the gauged site. Table 9 was used in
plotting the Flow Duration Curve for ungauged catchment which is shown in Figure 19
Table 9: Calculation for the flows (m3/s) of ungauged catchment S/N Pp(%) Ordinates of flows for gauged site
vertically (Qgauged)
Qungauged= Qgauged x MAFungauged MAFgauged
1 0.19 209.995 224.547
2 0.55 189.995 203.1616
3 0.77 169.995 181.775
4 1.04 149.995 160.389
5 1.29 129.995 139.00
6 3.23 109.995 117.6176
7 6.51 89.995 96.231
8 17.82 69.995 74.845
9 43.5 49.995 53.459
10 83.6 29.995 32.0736
11 99.9 9.995 10.6876
62
Figure 19: Flow Duration Curve for ungauged Kilondo catcment From the graph;
The minimum flow of water is 10.6976 m3/s
Discharge at 20% Percentage time, Q20% =70 m3/s
Discharge at 80% Percentage time, Q80% = 34 m3/s
Discharge at 95% Percentage time, Q95% = 19m3/s
4.7 Identification of potential micro hydropower plant site This process was done by using the topographical map which was collected from the
Ministry of Lands and Settlement Development. Elevation – distance graph, this was
drawn using the software called Arc View GIS, which extracted the table from the
selected points and obtained their elevations and distances,
Then profile of Kilondo River was drawn by using Microsoft Excel work sheet. A graph
of elevation against distance is drawn and shown in Figure 20 below.
63
Figure 20 :The profile of Kilondo River showing elevation against distance from the outlet(Nyasa Lake shoreline) From the graph above (Figure 20) the profile of the river, the distance and elevation of
the two points indicated on the graph are for Red arrow(900m,530m) and Green arrow
(1475 m, 650 m).
Hence the difference in the elevation = 650 m – 530 m = 120 m
The difference in elevation of the point is equal to gross head of 120 m
Waterfall
Outlet
Kilondo River
64
Figure 21: Kilondo River water falls located at (S 9° 44.23”, E 34° 18.93”) Source: Author (2010)
4.8 Head Measurement The elevation of the downstream and upstream was recorded and the difference gave the
required gross head (H). Let the downstream elevation be HD (m), Upstream elevation
be HU (m), and Gross Head be H (m) .From the survey: HU = 506.9 m, HD = 623.9 m, H =
HU – HD = 623.9 – 506.9 Head (H) = 117m
4.9 Determining Power Potential Power potential is obtained from Equation (01). Designed flow selected is Qo= 19m3/s
m3/s which is 95% Percentage time flow of water obtained from Flow duration curve of
ungauged catchment and using a measured head of 117m power potential of the Kilondo
river is obtained from
P (kW) = Q (m3/s) ×H (m)
65
The best turbines can have hydraulic efficiencies in the range 80% to over 90% (higher
than all other prime movers), although this will reduce with size. If we take 70 % ( as a
typical water-to-wire efficiency for the whole system (BILA, 2005) then the above
equation simplifies to:
P = 7 x 19 x 117
P = 15561 kW
Power = 15.561 MW
Energy output for 25 years
Energy = 15561 x 8760 x 25 = 3407859000KWh
= 3407859 MWh
Figure : 22 Load Duration Curve For Kilondo River
66
4.10 Determination of load and energy demand for Kilondo village Demand forecast for Kilondo Village for 25 years was determined using the following
equation.
TD = D (kW) x (1+γ) x n = D (1+n) n ………………………………………………. (16)
TD – Total load after n years; D – Load in kW; γ – Annual load growth rate; and
n – Number of years
Table 10 below shows different classification of loads at Kilondo village. Total load
demand after 25 years is expected to be 9819.765 kW. Demand for electricity at Kilondo
village will be increasing linearly.
Table 10: Peak load (kW) for 25 years for γ = 0.25 Period
(years) Classified load γ n Load (kW) (1+γ) Total
Load (kW)
1-4 Residential customers 4 0.25 39.6 1.25 198
Light commercial 4 0.25 16.7 1.25 83.5
Other social services 4 0.25 0.4 1.25 2
Light industry 4 0.25
30 1.25 150
Total load after 4 years 433.5
for γ = 0.04 ,0.03 and 0.02
5-25 Residential customers 21 0.04 198 1.04 4324.32
Light commercial 21 0.03 83.5 1.03 1806.105
Other social services 21 0.02 2 1.02 42.84
Light industry 21 0.02
150 1.02 3213
Total load after 25 years 9819.765
67
Energy demand (MWh) for 25 years
NB: 1 year is 8760 hours
TE = D x n x 8760 hours per year [kWh]; TE = Total energy demand after n years;
n = Number of years; and D = load (kW)
4.11 Selection of Turbine
Turbine is selected based on the output power of the turbine and available head for the
site. From figure 11 the type of turbine which is suitable for this plant is Francis turbine.
Where Head (h) = 117m and Power =15561 kW.
4.11.1Determination of specific speed of the turbine, n (rpm) Specific speed,
Ns = 3470Hn-0.625
= 3470*117-0.625 =176.8940 ≈ 177 for Francis turbine accepted range is 50 – 350 Ns = 177
Rotational speed, N
From the formula of specific speed which is
Ns = 25.1HPN
……………….…………………………………………………………(17)
Where N is turbine rotational speed (rpm), P is rated power (kW) and H head (m).
From above Turbine rotational speed N will be given by
N = 5.0
25.1 *P
NH S
N= 177*1171.25 155610.5
68
N=545.992 rpm
4.11.2 No. of poles, p
p = )(
50*120rpmN
…………………………………………………………………………(18)
p = 546
50*120
P = 10.989 ≈ 12 poles or 6 2 pole pair
Adjusted speed, N = 12
50*120 = 500 rpm
4.11.3 Check of Cavitations
In order to have a sound operation of turbine it should be insured that cavitation would not occur
on turbine blades. Cavitations should be kept in a certain range, which will not cause erosion or
pitting. The limit is defined through the dimensionless term called Thoma’s coefficient as
follows:
σ = …………………………………………………………(19)
Where; hb = Barometric head; hw = Vapour pressure head; and hs = static head (height
of the turbine above the discharge level)
But for tropical regions hb and hw can be considered as constants and equal to 10.3m and
0.237m respectively.
Therefore;
σ = 117
237.03.10 Sh−−
For Francis turbine cavitation factor is sc = 0.625 (Ns/444)2
69
= 0.09932
Substitute into above equation 11.62044 = 10.063 - hS
hs = 1.55744
Net Positive Suction Head (NPSH) = hb-hw-hs = 10.3-0.237-1.55744 = 8.50556
=8.50556 >>0
Since NPSH >>0 then no cavitations
Therefore the Center Line (CL) of the turbine runner is below the maximum discharge
water level by 1.55744m
Figure 23: Cross section of Francis runner
D3= 84.5(0.31 +2.488.ηQE)N
H N
*60(ESHA,2004)……………………………………(20)
D3= 84.5(0.31+2.488. ηQE) x 1170.5/60*500
D3 = 84.5(0.31+2.488. ηQE) x 0.000360555
ηQE = 75.0EQN
E = gH =specific hydraulic energy of machine = 9.81*117 = 1147.77 J/kg
Q = Designed flow, N = Rotational speed,
ηQE = 500 x 190.5/1147.770.75 = 11.05237
70
D3 = 84.5(0.31+2.488. 11.052)*0.000360555
D3 = 0.847 m
The inlet diameter D1 is given by the following equation
D2 = (0.4 +QEη095.0 )*D3…………………………………………………………………….(21)
D2 = (0.4 + 0.00859) x 0.847
D2 = 0.346 m
D1 = QE
Dη*3781.096.0
3
+…………………………………………………………….(22)
D1 = 0.847/0.96+0.3781 x 11.05237 = 0.164 m
4.12 Design of Civil Structure
Based on the survey results, the preliminary design was accomplished at prefeasibility
level to determine the main specifications of the facilities and equipment.
Height of Flood Barrier Walls
Height of intake barrier walls, Hb is the height to which water is likely to rise in the
worst flood condition Figure 24.
71
Figure 24: Intake and Weir
The characteristic discharge of the weir is given by equation 23
Q= 23
** HLC ………………………………………………………………………(23)
Where Q= QR river discharge (m3/s), Cd= Coefficient of discharge for the weir, HOT=
head-overtop of weir (m), L= LW length of weir (m).
Hh
H Over-Top
w
Hb
hhhhh
d Down stream river surface
Upstream river surface
Wh
72
Let length of the weir (LW ) is the same as the width of the River which is 20m. Mean
discharge of Kilondo River is 43.32m3/s and coefficient of discharge of the weir Cd is
0.494. Substituting these into the equation (23) to find head over top of weir (HOT)
HOT= 32
*
W
R
LCQ
……………………………………………………………………... (24)
HOT = (43.32/0.494*20)2/3 = 2.67 m.
Height of weir hweir is 1m, so the height of flood barrier wall will be given by
Height of barrier/wing Hb= HOT+ hweir = 2.67+1= 3.67m
Intake dimension
The intake behaves according discharge equation;
Q = AiVi = AiCd ( )hr Hhg −2 ………………………………………….…………..(25)
Where
Q = discharge through the intake; Vi= velocity of water passing through intake m/s; Cd =
coefficient of discharge of intake orifice (0.6<Cd<0.8); Ai = cross sectional area of
intake, Hr= depth of water in river channel in m; hh = depth of water in head race in m.
The intake dimensions are determined under two conditions; normal condition when
there is no flood and under flood conditions.
73
Normal condition
Under this condition Hh = d, the depth of intake opening hr is computed from equation
(25)
hweir is assumed and set to 1 m during normal conditions HOT = 0
hr (normal) = hw + HOT = 1.0 m
from equation (26)
Vi = Cd )(2 hr Hhg − .................................................................................................. (26)
This velocity is assumed to be 2<Vi<4 m/s . Assuming a velocity of 3m/s and coefficient
of discharge of an intake of 0.7 substituting into equation (26) height of intake (Hh) is
obtained.
3=0.75 x (2 x 9.81 x (1-Hh))1/2
Hh = 0.796 ~0.8m
From Qgross = AiVi = d*W*Vi....................................................................................... (27)
Where Qgross= Qd(design flow) = 19m3/s, d=depth of intake opening which is calculated
above as 0.8m, Vi= velocity of intake assumed to be 3m/s we can calculate the width of
an intake by using equation (28)
W = i
gross
VdQ
*…………………………………………………………………………… (28)
W = 19/0.8 x 3 = 7.9 m
Headrace slope and width (normal flow condition)
Velocity of Vh = 2m/s is considered good practice and chosen as a first assumption. This
is the maximum allowable velocity for concrete beyond which channel erosion will
74
occur. The headrace slope must be such that this velocity is maintained. Water depth
hnm(normal) is assumed to be equal to d as discussed above.
Let hnm (normal) = d= 0.8M
Wh = width of headrace canal
Ah = cross-sectional area of headrace canal
Qgross = Vh*Ah = Vh*hnm*Wh………………………………………………………..(29)
Wh = hnh
gross
hVQ
*
Wh = 19/2*0.8 = 11.875m. Therefore the width of headrace calculated is 11.875m
Figure 25 Section of Headrace
Slope of headrace is found using Manning’s equation
S = 2
667.0
*
RVn h ……………………………………………………………………….... (30)
S = (0.03*2/0.7050.667)2 = 0.075
Where
S = slope of the headrace
hh = d
Wh
75
R = hh
hh
hWhW2
*+
= PA…………………………………………………………………(31)
R = 11.875*0.8/11.875+2*0.8 = 0.705
n = roughness value for the material of the headrace.
Spillway Design
The length of spillway Lspw is found from standard weir equation
Q = 5.1)(** OTww hLC …………………………………………………………..….. (32)
In this scenario the following conditions exist. Height of the spillway crest Hspw is
aligned to the normal flow surface level or water depth.
Hspw = hhn
HOT = Hmf - hhn
Lspw = Lw= 20 m.
Lspw = 5.1)( topoverw hC
Q
−
……………………………………………………………… (33)
= 5.1)( spwmfw
gmf
hhCQQ
−
−………………………………………………………...….. (34)
Where minor flood = 1.15 Qg
Hmf = 1.15 hspw………………………………………………………………………. (35)
Desilting Tank
Desilting tanks are often provided in the head reaches of canals and other water
conducting systems to traps as much as possible sediment in the water and thereafter
producing as sediment free water.
76
A basin for micro-hydropower scheme is often designed to remove particles with
diameter greater than 0.3mm with corresponding settling velocity of about 0.03 m/s
(Table 11).
Table 11: Vertical velocities of particles
Particle size mm Vertical m/s
0.1 0.02
0.3 0.03
0.5 0.1
1.0 0.4
The depth of basin is given by
D = 1.3 Q…………………………………………………………………………..(36)
D = 1.3 x (19)0.5 = 5.7m
Specific volume of desilting tank (Vs) = 50.7 Q………………………………… (37)
VS = 50.5 x (19)0.5 = 220.124 m3
Tank Volume (VT) = VS*Q = 220.124* 19 = 4182.363 m3
Length of the desilting is given by;
L = D
VT
*4…………………………………………………………………………. (38)
L= (4182.363/4*5.7)0.5 = 13.54 m
Width of the desilting tank is given by;
77
W = 4L
= 13.54/4 = 3.385 m
Forebay
Forebay is usually designed for a live storage of 2 minutes. Based on this the volume is
given:
Volume of Forebay = Q*2*60 m3………………………………………………….. (39)
To size the forebay, we assume a depth d and calculate L and B
Where: L = length of forebay (m); B = width of forebay ( m) ; Q = flow into forebay
(m3/s); and Penstock diameter Ø = D, free board = 0.6H , and H= 1.5 to 2D
From equation (39)
Volume of forebay = 19*2*60 = 2280 m3
Assuming a depth of 10m and of 6m the length of forebay tank will be
Length= 2280/10*6 = 38 m
Channel
The length of the channel/canal is estimated from the topographic map and is 800 m. A
slope of this place is 0.15 also obtained from map. Open channel made of concrete is
designed. Flow capacity is given by the following equation;
Qd = n
SRA 2/13/2 **…………………………………………………………………. (40)
Where
A= cross sectional area; R= Hydraulic radius (A/P); P = length of wet sides
S = Longitudinal slope; and n = coefficient of roughness
78
Designed channel is a rectangular half square with the following specification (ESHA,
2004): Area (A)= 2y2 ; Wetted perimeter P= 4y ; Hydraulic radius R = 0.5y ; Top width
T= 2y ; and Water depth d = y. Putting A and R of equation (55) in terms of y we get;
Q = n
Syy 2/13/22 *)5.0(*2…………………………………………………………. (41)
From equation (41) putting n = 0.012, S= 0.15 y is calculated.
Q= 1.2Qd= 1.2 x 19=22.8m3/s
22.8 = 2y2 x (0.5y)2/3 x 0.150.5/0.012
y = 1.044m
Now area of cross-sectional area of a channel
A= 2y2= 2 x 1.0442= 2.18 m2;
Wetted perimeter P = 4y= 4 x 1.044= 4.176m;
Hydraulic radius R = 0.5y = 0.5*1.044 = 0.522m;
Top width T = 2y = 2 x 1.044 = 2.088 m;
Water depth d = y = 1.044 m
Penstock
In designing penstock the length of a penstock (L) is determined from topographic
map. In this project the length of the penstock is 750 m. Restrict head loss to 5% of the
gross head is considered good practice:
1fh
= 33.5
223.10D
xLxQxn … ………………………………………………………….(42)
Where
He = head loss in penstock (m); hg = gross head (m); and L = length of penstock (m)
79
Using equation 42 and substituting values of n, Q, L and limiting frictional losses to 4%,
we can find the diameter of penstock by using the following equation;
D = 1875.022
69.2
H
xLxQn..……………………………………………………….. (43)
D = 2.69(0.0122 x 192 x 750/117)0.1875 = 2.2 m
Pipe Thickness
The pipe thickness t for a pipe of internal diameter D and internal pressure P is given by
ti = S
PxD +es……………………………………………………………………….(44)
Where
ti = pipe thickness (m); P = pressure (m of water); D = pipe internal diameter (m);
S = design stress of pipe material (N/m2) = ultimate tensile strength/safety factor
es = extra thickness to allow for corrosion = 30 mm
Pressure of water = Pa + ρgh………………………………………………………..(45)
Where
Pa= atmospheric pressure at water surface, ρ = water density, g= acceleration due to
gravity, h= head of water.
From equation 45
P= 1.103 x 105 + 1000 x 9.81 x 117
P = 110300 + 1147770 = 1258070 N/m2
80
Material selected for this penstock is welded steel with ultimate tensile strength of
400*106 N/m2 (ESHA, 2004) with a safety of factor of 2.
From eqn (44) pipe thicknesses is calculated as follows
ti = 1258070 x 2.2 x2/400 x106
ti = 0.013838 m + 0.003 = 0.016838 = 16.838m ~ 17 mm.
Therefore pipe thickness of the penstock is 17 mm.
Layout of Kilondo Hydropower and some drawing are shown in appendix M.
4.13 Social Impact Assessment (SIA) A social impact survey was done to analyze and predict future social and economic
effect of Kilondo hydropower plant. All potentially affected working groups were
identified and these are: People lives nearby hydro power plant; those who will hear,
smell or see a development; those who are forced to relocate because of the project; and
those who have interest in a new project or policy change but may not live in proximity.
Once identified, a representative from each group was systematically interviewed to
determine potential areas of concern/impact, and ways each representative may be
involved in the planning/ decision process. Survey data was used to define the
potentially affected population. In the next step, the proposed action was described in
enough detail to begin to identify the data requirements needed from the project
proponent to frame the SIA. Social safeguards screening checklist shown in appendix 9
is a guide for obtaining data from policy or project proponents.
Population of Kilondo Village is 1130 people with 330 households scattered with one
primary school, one dispensary and five small shops at the trading center and two grain
81
mills. The main economic activity of the people is fishing and agriculture. The village is
headed by the Village Executive Officer (VEO) who is employed by the Local
Government. There is a Village chairman who is elected by all villagers.
4.14 Environmental Impact Assessments
The purpose of a preliminary environmental assessment is to identify and assess the
natural and social impacts of this project and to propose counter measures to avoid or
reduce any impact. Based on the current status of the natural and social environment
conditions in the study area was confirmed through interviews with the village
representatives in Kilondo Village, as well as by actually surveying the project area.
Also a number of major environmental impacts selected from VPO- EIA checklist was
adopted (Appendix J). The assessment showed that no impact items relevant to ratings A
and B (A: major environmental impact; B: medium level environmental impact) were
applicable for this project. However, some items relevant to rating C (minor
environmental impact) were identified as follows: Deterioration of landscape Flow
conditions change; and Impact on flora, fauna and aquatic life. The above identified
impact items are regarded as impacts generally caused by hydro power projects
regardless of the scale of the development. However, it is considered from the following
reasons that these impacts are not a major concern under the project development. It was
confirmed from interviews of village representative that there are no protected species of
animals or plants in and around the project area and also that water is not used for
irrigation, fishing, drinking, bathing, washing, etc, in Kilondo River. Between the intake
site and power station, where the stream flow condition would change upon operation of
82
the facilities. The land alteration due to the installation of power generation facilities is
limited due to the small scale of the project, and therefore there will be only a minimal
influence on the forest area. Consequently, it can be considered that there are no serious
environmental impacts as a consequence of the development of this project.
4.15 Economical Appraisal The economic analysis is a comparison of costs and benefits that enables the
investor/investors to make an informed choice whether to develop the project or
abandon it (ESHA, 2004). Small hydro costs can be split into four segments which are:
Machinery, Civil works and external costs. Payback method was used to validate the
viability of the Kilondo hydropower project. The payback method determines the
number of years required for the invested capital to be offset by resulting benefits. The
required number of years is termed the payback, recovery, or break-even period. In
evaluation of economic analysis of this project RETScreen module was used. Initial
cost of the project is $ 7,805,206. Tarrif set by EWURA for selling wholesale to DNO
(currently TANESCO) connected to isolated mini-grid is 85.49 Tzs/kwh (EWURA,
2009). Kilondo hydropower plant of producing 130229MWh electrical energy annually
which and its total annual savings and income is $ 6,511,445 which gives a payback
period of 1.2 years. Figure 26 shows the financial viability of the project as calculated by
the RETScreen module. The details of the cost of the project are shown in the appendix
N
83
Financial viability Pre-tax IRR - equity % 228,6% Pre-tax IRR - assets % 68,6% After-tax IRR - equity % 187,1% After-tax IRR - assets % 55,7% Simple payback yr 1,2 Equity payback yr 0,5
Net Present Value (NPV) $ 39 622
474
Annual life cycle savings $/yr 4 108
443 Benefit-Cost (B-C) ratio 17,93 Debt service coverage 5,63 Energy production cost $/MWh 10,59
GHG reduction cost $/tCO2
(150) Figure 26: Financial viability of Kilondo Hydropower plant.
4.16 Hydrological Modeling RETScreen module is set up in spread sheet environment and comprises four screens
which are: Energy data model; Cost analysis; Emission analysis; Financial analysis; Risk
analysis; and Tools. In the energy model the input data are: Gross head , Maximum tail
water effect, drainage area, specific run-off, residual flow, percent time firm flow
available, design flow, generator and transformer losses and parasitic losses and
hydrologic and equipment parameters (Table 16 ) and the module calculates Annual
energy production of 18 027kW. Flow duration curve (FDC) of Kilondo River was
entered in the energy module and the obtained output was FDC and load duration curve
(LDC) in tabular and graphic formats as seen in the Figure 27 below.
84
Figure 27: Flow duration and power curves.
85
Figure 28: Graph of turbine efficience and percent of rated flow.
In cost analysis screen economic parameters of the project were entered and the module
calculated the capital cost.
86
CHAPTER FIVE
CONCLUSION AND RECOMMENDATIONS Conclusions The summary of main findings, based on the analysis undertaken in the preceding
chapters, is presented in this section followed by sets of key recommendations.
Electricity Demand
Electricity demand of Kilondo village was assessed to be 86.7 kW with a peak load of
108.375 kW. The demand of electricity in Kilondo is growing, it is estimated that load
forecast for 25years will be 9819.765 kW. Energy demand for Kilondo village is
949.365MWh while the capacity of Kilondo power plant is to produce 136314.36
(MWh) annually. So there a surplus of 135364.995 MWh of electrical energy this can be
brought to the national electricity grid and produce revenue.
Head and stream flow of the River.
Adequate head and flow are necessary requirements for hydropower generation (ESHA,
2004). Kilondo river have a potential for producing electricity. The available head was
measured and was 117m. Kilondo river is a perennial it have some flow at all times of a
year. The designed flow for this plant is 19m3/s which is available at 95 percentage of
time and gives a power of 15.61 MW.
Preliminary design of small hydro power plant.
Preliminary design of Kilondo hydropower plant was carried out. The following civil
work components were designed: Weir and intake, headrace, spillway, desilting tank,
forebay tank, channel, and penstock. Francis turbine was selected since it meets both
head and power which can be produced by the plant.
87
Environmental impact assessment The checklist for environmental impact assessment for Kilondo Hydropower plant was
grouped into the following: Social and natural environment aspects. Both of them show
that they have no negative impact to the environment.
Findings of Social Analysis The benefits of rural electrification are undeniable, especially for the enhancement of
rural people’s live hood. The Project will bring about various positive social impacts. It
will directly contribute to economic growth and will reduce poverty by lowering
household energy costs and removing energy constraints to enterprises that offer
employment opportunities to the poor. Direct benefits will extend to all categories of
electricity consumers served by the plant; poor and vulnerable, and indigenous groups.
Benefits will include improvements to the existing quality of electricity supplied to
households, better quality lighting at cheaper prices than required for kerosene and/or
diesel, and improved air quality within homes. Infrastructure development is critical to
generating economic activity, employment, accelerating growth, and providing better
integration and social welfare. The Project will contribute to poverty reduction and will
specifically benefit people living in remote areas through a new source of electricity, and
improved frequency and voltage levels for various uses that will ultimately result in
socioeconomic growth. Overall, the social impact of the Project was determined to be
positive for the local population and the country as a whole. The need for employment
of locals is relatively high; the development is segregated from residential areas and is
88
located at sufficient distance from existing settlements to avoid serious impact on
residents.
Economical Appraisals of Kilondo hydropower plant RETScreen module was used to analyze economic viability of Kilondo hydropower
project. From the module we get a payback of this project to be 1.2 years. Initial cost of
the project is $ 7,805,206 and estimated annual revenue is $ 6,511,445.
Modeling of RETScreen module RETScreen module was used to analyze the viability of the project. The output
calculated from this module were: Firm flow (35m3/s), Turbine peak efficiency (93.1%),
Flow at peak efficiency (15.2 m3/s), Maximum hydraulic losses (89.7), power capacity
(18,027kW), Capacity factor (82.6%) and electricity exported to grid (130,375MWh)
Sustainability of Kilondo Hydropower plant Sustainable small hydropower needs integration of three components economic, social
and environmental protection as interdependent mutually reinforcing pillars. For
Proposed Kilondo hydropower plant all these aspects has been addressed. Its benefits
have been maximized and negative environmental, social and economic impacts have
been avoided. At Kilondo village there is demand electricity and people are eager to pay
for electricity bills. The payback period for this project is 1.2 years as calculated from
the RETScreen module. In economic aspect Kilondo hydropower plant will: provide low
operating cost, provide long life span, meets loads flexibly, provide reliable sources,
instigates and foster rural development, provides highest energy efficiency rate (payback
ratio), generate revenue to sustain other water uses, creates employment opportunity,
89
saves fuel consumption, provides energy dependence by exploiting rural resources.
Socially Kilondo hydropower plant will: leave water available for other uses; provides
opportunities for construction and operation with a high percentage of local manpower;
sustain live hoods. Environmental impact assessment for Kilondo hydropower plant has
been done and shows there is negative impact on it. However the proposed project will
bring the following benefits: produces no atmospheric pollutants and other green house
gases emissions; enhance air quality; avoids depleting non-renewable fuel resources;
creating new freshwater ecosystems with increased productivity; and will helps to slow
down climate change. Proposed small hydropower plant will be sustainable and can be
implemented.
Recommendations. For the Kilondo hydropower scheme to be sustainable there is a need to recognize
entitlements and share benefits with directly affected people. A legal framework needs
to be developed for enabling either the community or utility or any other private entity to
take over the management of Kilondo hydropower system. The frame work should
determine who would be responsible for paying for power injected into the grid.
However there should be establishment of spin-off activities made possible via use of
the generated electricity such as agro processing factories, manufacturing industries, and
promotion promotion of use of electricity in all new investments and redesigning of
existing structures for business and social services. Finally there should be established a
mechanism for training local electrical technicians, engineers and management
personnel for system maintenance.
90
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APPENDICES
APPENDIX A: Diversified Unit Load and Group Diversity Factors for Classified Loads S/N Classification of load Consumer Diversified unit
load (D) Group Diversity Factor
(kW) (kW) 1 Residential Small load house 0.2 0.6 Medium load house 0.8 0.6 Large load house 2.0 0.6 2 Light commercial Small restaurant 0.2 0.6 Hotel/Camp 2.0 0.6 Bar 2.0 0.6 Guest house 2.0 0.8 Small shop 0.2 0.6 Shop 1.0 0.8 Court 0.2 1.0 Garage 1.5 1.0 Small workshop 2.0 1.0 Go down 0.5 1.0 Ward/Division H/Q 2.0 1.0 Custody 0.2 1.0 Police station 1.0 1.0 Office 2.5 1.0 Petrol station 1.0 1.0 Youth/Women centre 2.0 1.0 Community centre 2.0 1.0 Hospital/health centre 50 1.0 Dispensary 0.5 1.0 Bank 2.5 1.0 Post office 0.5 1.0 College 20 1.0 Primary school 2.0 0.8 Secondary school 20 0.8 Tailoring 2.0 0.8 Mission 50 1.0 Market 1.0 1.0 Carpentry 2.0 1.0 3 Light industry Grain mills** 15 1.0 Water pump** 25 1.0 4 Church 0.5 0.8 Mosque 0.2 0.8 Street lights 0.5 1.0 5 Heavy industry Plant 0.75
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6 solar Generator Car batteries
APPENDIX B: Demand Survey Questionnaire 1. General data 1. 1. Region……………………………………………………………….. 1.2 District………………………………………………………………… 1.3 Ward………………………………………………………………… 1.4 Village………………………………………………………………. 2. Accessibility 2.1 From District Headquarters to Village Distance km Road condition Asphalt: km rocks: km soil: km
Other: km Trip time Transportation mode Public vehicle/bus motorcycle
Ship/ferry others…………………….. 2.2. Village to site location Distance km Road condition Asphalt: km rocks: km soil: km
Other: km Trip time Transportation mode Public vehicle/bus motorcycle
Ship/ferry others…………………….. 3. Demography Location of Small Hydro Power Potential 3.1 Total population Person 3.2 Total family head Family head 3.3 Total house House 3.4 Living source 3.5 Population distribution Spread centralized grouping………… 3.6 Income per month 3.7 Public organization Multipurpose farmer group religious group 4. Village Infrastructure 4.1 Public facility 4.2 School Elementary school/Junior High school/
Senior high school/other……… 4.3 House of worship Mosque church other……… 4.4 Health services Local government clinic others…… 4.5 Government offices Village, ward other……. 4.6 Productive business 4.7 Market None / exist daily weekly 4.8 Small industry 4.9 Economy Potential 4.10 Others………. 5. Location of Small Hydro Power Plant 5.1 Location
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5.2 River 5.3 Status of land ownership Private village donated land other….. 5.4 Location condition Heavy area in forest near strategic
Value: 1 2 3 4 5 6 7 8 9 10
APPENDIX C: Questionnaire for Households of Non-Electrified Villages Name of respondent____________________________________________________________ Interviewer’s name____________________________________________________________ Date_______________________________________________________________________ A. Family profile 1. Number of family members(only living together in the same house) Male adults at 20 years or over __________________persons Female adults at 20 years or over _________________persons Children less than 20 years ___________________persons Total __________________persons 2. Number of children going to school
University student __________________ persons High school student __________________ persons Secondary school student _________________ persons Primary school student _________________ persons Total _________________ persons
3. How many of your family members are earning income in the village?______pesrons 4. How many of your family members are living in other town to work?______ persons 5. Is your household headed by male or female?
Tick(√) Male Female
6. How many of your family members graduated from high school?
B. Housing
7. How many rooms does your house have ? ___________ rooms
8. What is floor area of your house? __________ m2
9. What type of roof is used for the house ?
Type of roof Tick(√)
Tiled roof
GI sheet roof
Thatched roof
C. Economic aspects Household income 10. How much is your family earning from agriculture?
Type of crops
Average amount of production per cropping(kg)
Time of cropping per year
Average farm gate price(Tsh)
Approximate annual earning(Tsh)
Subsistence /cash crop
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11. Earning from fishery
Type of fish Annual average earning(Tsh)
Annual average cost(Tsh) Subsistence/cash
12. What kind of income sources does your family have? Insert the amount of earning of the last month in each category by each income earner.
Income earner 1st income earner 2nd income earner
Salaries/wages
Pension
Handicraft
Other cottage industry
Shops/restaurants
Services(e.g. hair-dress, car garage)
Money transfer from outside village
Other(specify)
Total
Household Expenditure 13. How much did your household spend on each item for the last month?
No Item of expenditure Amount
1 Food
2 Clothing
3 Housing
4 Inputs for business
5 Utilities
6 Tax
100
7 Education
8 Transportation
9 Health care
10 Others
Total
14. How much did your household spend on the utility expect energy for the last month?
No. Item of expenditure Amount
1 Portable water
2 Irrigation water
3 Sanitation
4 Others
Total
15. How much did your household spend on the energy-related item for the last month?
No. Item of expenditure Amount
1 Electricity
2 Gas
3 Solar power
4 Kerosene
5 Diesel oil
6 Coal
7 Charcoal
8 Fuel wood
9 Dry batteries
10 Candles
11 Matches
12 Car battery charging
13 Others
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Total
16. If Kilondo village is to be electrified and your house is to be connected with electricity distribution systems, all of your existing costs for lighting and heating as mentioned above may be saved. In this case , how much monthly charge are you willing to pay for new electricity services?
Range(Tsh./month) 1000 ~
3000
3000~
6000
6000 ~
9000
More than 9000(specify)
Tick(√)
D. Energy Related Property 17. Do you have the following equipment for lighting and/or heating?
Kind of equipment
a) Generator
b)kerosene lamp
c)Gas fired cooking appliance.
d) Car battery
e) Others(specify:)
Number
18. What kind of electrical appliances does your household currently use?
( )Bulb/fluorescent light ___________________units ( )TV – set _____________units ( ) Radio & cassette recorder set _____________ units ( )Refrigerator _____________ units ( )Air conditioner ____________ units ( ) Other, specify_______________ ____________ units
19. What kind of electrical appliances does your household currently use for productive activities?
( ) Saw mill machine ( ) Rice milling machine ( ) Rice dryer ( ) Irrigation pump ( ) Other, specify ________________________________________
E. Needs for Electricity Priority needs 20. Could you give your priority order on the following needs?
Priority
Water supply
Education
Health care
Sanitation (toilet, solid waste, drainage, etc)
Electrification
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Irrigation
Road improvement
Others (specify)
Effort to have access to electricity 21. Has your household ever attempted to have access to electricity?
( ) If Yes go to question 22 ( )If no go to question 29
22. What type of electricity generation did your household plan to have access to? ( ) Diesel generator set ( ) Solar home system ( ) Wind power ( ) Micro hydropower ( ) Biomass ( ) Other specify_______________________
23. Specify the reason for selecting the type of electricity generation
24. Did your house hold succeed in having access to electricity? ( ) If Yes go to question 25 ( ) If no go to question 26
25. Is your generating system functioning as expected?
( ) If Yes go to question 27 ( ) If no go to question 28
26. If your household did not succeed in having access to electricity , explain the reason for the failure. 27. What positive impact could your household receive from electricity? Explain. 28. What problems did your household encounter regarding facility?
Problem Tick(√)
Expensive cost of fuel
Unable to fix breakdown
Insufficient electric power to meet the demand
Other(specify)
Purpose of using electricity 29. If you can have access to electricity, what kind of electrical appliances and how many appliances do you want to use?
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( ) Bulb/fluorescent light ___________________units ( ) TV – set _____________units ( ) Radio & cassette recorder set _____________ units ( ) Refrigerator _____________ units ( ) Air conditioner ____________ units ( ) Other, specify_______________ ____________ units
30. What kind facility/equipment do you want to use electricity for productive activities? ( ) Saw mill machine ( ) Rice milling machine ( ) Rice dryer ( ) Irrigation pump ( ) Other, specify ________________________________________
31. What public facilities do you think should have access to electricity? ( ) School ( ) Mosque/church
( ) Clinic/health center ( ) Water pump for drinking water ( ) Others, specify__________________________________________
Electrification by the organization other than TANESCO 32. Who/what organization do you think would be the most appropriate for the installation of the electricity supply
system?
( ) Central government ( ) Local government ( ) NGO
( ) Private Investor ( ) Village members (including village head)
( ) Others, specify___________________ ( ) don’t know
33. Do you and /or your family member volunteer to participate in working for the construction without any cash reward if the generating facility is to be installed in the village?
( ) yes ( ) no
34. Who/what organization should be responsible for operation and maintenance of the system?
( ) Central government ( ) Local government ( ) NGO
( ) Private Investor ( ) Village members (including village head)
( )Others, specify___________________ ( ) don’t know
35. Do you and/or your member want to participate in working for operation and maintenance? ( ) Yes ( ) no
36. Who/what organization should be responsible for billing and collection of charges for electricity?
( ) Central government ( ) Local government ( ) NGO
( ) Private Investor ( ) Village members (including village head)
( ) Others, specify___________________ ( ) don’t know
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37. How should the electricity tariff be decided? ( ) Same level as TANESCO tariff system
( ) Based on consultation with and consensus of the community
( ) Free of charge
( ) Other, specify____________________
APPENDIX D: Number of Identified Consumers in Kilondo-Ludewa
NUMBER OF IDENTIFIED CONSUMERS IN KILONDO VILLAGE
S/N Classification of load consumer Number 1 Residential Small load house 330 Medium load house 0 Large load house 0 2 Light commercial Small restaurant 0 Hotel/Camp 0 Bar 0 Guest house 0 Small shop 5 Shop 0 Court 0 Garage 0 Small workshop 1 Go down 0 Ward/Division H/Q 1 Custody 0 Police station 0 Office 2 Petrol station 0 Youth/Women centre 0 Community centre 0 Hospital/health centre 0 Dispensary 1 Bank 0 Post office 0 College 0 Primary school 1 Secondary school 0 Tailoring 0 Mission 0 Market 1 Carpentry 2 3 Light industry Grain mills** 2 Water pump** 0
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4 Church 2 Mosque 0 Street lights 0 5 Heavy industry Plant 0 6 solar 2 Generator 2 Car batteries 0
APPENDIX E: Load Demand Determination for Kilondo-Ludewa (Individual Load Demand) Number Of Identified Consumers In Kilondo- Village
nc*Du
S/N Classification of load consumer Number (nc) Diversified unit load (Du) Load(D) (kW) (kW)
1 Residential Small load house 330 0.2 66
Medium load house 0 0.8 0
Large load house 0 2.0 0
2 Light commercial Small restaurant 0 0.2 0
Hotel/Camp 0 2.0 0
Bar 0 2.0 0
Guest house 0 2.0 0 Small shop 5 0.2 1
Shop 0 1.0 0
Court 0 0.2 0
Garage 0 1.5 0
Small workshop 1 2.0 2
Go down 0 0.5 0
Ward/Division H/Q 1 2.0 2
Custody 0 0.2 0
Police station 0 1.0 0
Office 2 2.5 5
Petrol station 0 1.0 0
Youth/Women centre 0 2.0 0
Community centre 0 2.0 0
Hospital/health centre 0 50 0
Dispensary 1 0.5 0.5 Bank 0 2.5 0
Post office 0 0.5 0
College 0 20 0
Primary school 1 2.0 2
Secondary school 0 20 0
Tailoring 0 2.0 0
Mission 0 50 0
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Market 1 1.0 1
Carpentry 2 2.0 4
3 Light industry Grain mills** 2 15 30
Water pump** 0 25 0
4 Church 1 0.5 0.5 Mosque 0 0.2 0
Street lights 0 0.5 0
5 Heavy industry Plant 0
6 Solar 2
Generator 2
Car batteries 0
APPENDIX F: Maximum Power in Kilondo Village INDIVIDUAL DIVERSIFIED MAXIMUM POWER IN KILONDO VILLAGE
Market Demand (MD)
S/N Classification of load
Consumer Load (D) Group Diversity Factor
Load
(kW) (Dg) (kW) (kW) 1 Residential Small load house 66 0.6 39.6 Medium load house 0 0.6 0 Large load house 0 0.6 0 Residential subtotal 39.6 2 Light commercial Small restaurant 0 0.6 0 Hotel/Camp 0 0.6 0 Bar 0 0.6 0 Guest house 0 0.8 0
Small shop 1 0.6 0.6 Shop 0 0.8 0 Court 0 1.0 0 Garage 0 1.0 0 Small workshop 2 1.0 2.0 Go down 0 1.0 0 Ward/Division H/Q 2 1.0 2.0 Custody 0 1.0 0 Police station 0 1.0 0 Office 5 1.0 5.0 Petrol station 0 1.0 00 Youth/Women centre 0 1.0 0 Community centre 0 1.0 0 Hospital/health centre 0 1.0 0 Dispensary 0.5 1.0 0.5 Bank 0 1.0 0 Post office 0 1.0 0 College 0 1.0 0 Primary school 2 0.8 1.6 Secondary school 0 0.8 0 Tailoring 0 0.8 0
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Mission 0 1.0 0 Market 1 1.0 1.0 Carpentry 4 1.0 4.0 Light commercial
Subtotal
16.7
3 Light industry Grain mills** 30 1.0 30 Water pump** 0 1.0 0 30 4 Church 0.5 0.8 0.4 Mosque 0 0.8 0 Street lights 0 1.0 0 0.4 5 Heavy industry Plant 0.75 6 Solar Generator Car batteries
TOTAL DIVERSIFIED MARKET DEMAND (kW) 86.7
APPENDIX H: Energy demand forecast for 25 years No. Year Energy demand (MWh) Production
(MWh) Surplus (MWh) Deficit
(MWh) 1 2010 949.365 136314.36 135364.995 0 2 2011 1898.730 136314.36 134415.63 0 3 2012 2848.095 136314.36 133466.265 0 4 2013 3797.460 136314.36 132516.9 0 5 2014 3915.4134 136314.36 132398.946 0 6 2015 7830.8268 136314.36 128483.534 0 7 2016 11746.240 136314.36 124568.12 0 8 2017 15661.654 136314.36 120652.706 0 9 2018 19577.067 136314.36 116737.293 0 10 2019 23492.480 136314.36 112821.88 0 11 2020 27407.894 136314.36 108906.466 0 12 2021 31323.307 136314.36 104991.053 0 13 2022 35238.721 136314.36 101075.639 0 14 2023 39154.134 136314.36 97160.226 0 15 2024 43069.547 136314.36 93244.813 0 16 2025 46984.901 136314.36 89329.459 0 17 2026 50900.374 136314.36 85413.986 0 18 2027 54815.788 136314.36 81498.572 0 19 2028 58731.201 136314.36 77583.159 0 20 2029 62646.614 136314.36 73667.746 0 21 2030 66562.028 136314.36 69752.332 0 22 2031 70477.441 136314.36 65836.919 0 23 2032 74392.855 136314.36 61921.505 0 24 2033 78308.268 136314.36 58006.092 0 25 2034 82223.681 136314.36 54090.679 0
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APPENDIX I: Social Safeguards Screening Checklist Social Safeguard Issues Yes No Not
Known Remarks
A. Involuntary Resettlement Impacts
(i) Identification of IPs/EMs in the Project Area. If there are IPs/EMs in the project area, assess project impacts on such groups. If there are no IP/EMs, no action is required.
- Are there population groups who have been living in the project location before modern states or territories were created and before modern borders were defined
√
– maintain cultural and social identities separate from mainstream or dominant societies and cultures
√
– self-identify, or by law or are identified by others part of a distinct indigenous cultural group or ethnic minority
√
– have a linguistic identity different from that of the mainstream society
√
– have social, cultural, economic and political traditions and institutions distinct from the mainstream culture
√
– economic systems oriented more toward traditional systems of production than the mainstream systems
– maintain attachments to traditional habitats and ancestral territories and the natural resources in these habitats and territories
√
-have established a presence and separate social cultural identity.
√
(ii) Do IPs/EMs maintain distinctive customs or economic activities that may make them vulnerable to hardship?
√ If there are significant impacts on IPs/EMs, prepare an IPDP/EMDP. (iii) Will the project restrict their economic and
social activity and make them particularly vulnerable in the context of project?
√
(iv) Will the project change their socioeconomic and cultural integrity?
√
(v) Will the project disrupt their community life? √
(vi) Will the project positively affect their health, education, livelihood or social security status?
√
(vii) Will the project negatively affect their health,education, livelihood or social security status?
√
(viii) Will the project alter or undermine the recognition of their knowledge, preclude customary behaviors or undermine customary institutions?
√
(ix) In case no disruption of indigenous community life as a whole, will there be loss of
√
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housing, strip of land, crops, trees and other fixed assets owned or controlled by individual indigenous households?
– Are national and local laws and regulations compatible with ADB’s Involuntary Resettlement policy?
√ If there are gaps, project specific resettlement principles and measures need to be incorporated in the RP.
– Will coordination between the Project Sponsor and Government agencies be required to deal with land acquisition?
√ If yes, institutional arrangements to deal with resettlement planning and implementation need to be outlined in the RP
– Does the Project Sponsor have sufficient skilled staff to undertake resettlement planning and implementation?
√ If no, capacity building requirements need to be described in the RP or RF.
– Are training and capacity-building interventions required prior to resettlement planning and implementation?
√
IR Impact Category Plan required
A Significant (200 people or more will experience major impacts) Full RP Full RP B Not significant (Less than 200 people will experience major impacts) Short RP Short RP
C √ C No impact None
B. Indigenous Peoples (IP)/Ethnic Minorities (EM) Concerns
(i) Identification of IPs/EMs in the Project Area. If there are IPs/EMs in the project area, assess project impacts on such groups. If there are no IP/EMs, no action is required.
- Are there population groups who have been living in the project location before modern states or territories were created and before modern borders were defined
√
– maintain cultural and social identities separate from mainstream or dominant societies and cultures
√
– self-identify, or by law or are identified by others part of a distinct indigenous cultural group or ethnic minority
√
– have a linguistic identity different from that of the mainstream society
√
– have social, cultural, economic and political traditions and institutions distinct from the mainstream culture
√
– economic systems oriented more toward traditional systems of production than the mainstream systems
√
– maintain attachments to traditional habitats and ancestral territories and the natural resources in these habitats and territories
√
110
- have established a presence and separate social cultural identity.
√
(ii) Do IPs/EMs maintain distinctive customs or economic activities that may make them vulnerable to hardship?
√ If there are significant impacts on IPs/EMs, prepare an IPDP/EMDP. (iii) Will the project restrict their economic and
social activity and make them particularly vulnerable in the context of project?
√
(iv) Will the project change their socioeconomic and cultural integrity?
√
(v) Will the project disrupt their community life? √
(vi) Will the project positively affect their health, education, livelihood or social security status?
√
(vii) Will the project negatively affect their health, education, livelihood or social security status?
√
(viii) Will the project alter or undermine the recognition of their knowledge, preclude customary behaviors or undermine customary institutions?
√
(ix) In case no disruption of indigenous community life as a whole, will there be loss of housing, strip of land, crops, trees and other fixed assets owned or controlled by individual indigenous households?
√ If relocation is required, a combined IPDP/EMDP and RP may be prepared.
IP Impact Category Plan required:
A Significant IPDP/EMDP B Not significant Specific Action in the RP
C No impact None
RP- Resettlement Plan
EMDP- Ethnic Minority Development Plan IP- Indigenous Peoples AP- Affected Person EM- Ethnic Minorities
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APPENDIX J: Checklist for Environmental Impact Assessment
Impact Items Evaluation Reasons
Social Enviroment
Population 1 Change in the local population distribution (minority ethnic group problem included) X
2 Relocation (minority ethnic group problem included) X
Industry 3 Agriculture and forestry C
4 Fishery C
5 Secondary Industry (mining and mineral resources included) X
6 Tertiary industry (tourism and recreation included) X
Communication 7 Local cut-off (minority ethnic group problem included) X
Transportation 8 Influence on land transportation X
9 Influence on water transportation X
River basin and its utilization 10 Influence on water rights and fishing rights etc C
Sanitation conditions
11 Occurrence and transmission of river basin related diseases C
12 Deterioration of sanitary environment during construction D
Scenery 13 Deterioration of land scape B
Cultural assets, etc 14 Influence on cultural assets X
Natural Environment
Toposphere
Subject 15 Influence on inducible earthquakes D
Topograph 16 Slope slide B
17 Sedimentation in beck water area C
18 Influence on downstream channels X
19 Influence on beaches X
Geology 20 Soil erosion C
21 Soil contamination X
Hydrosphere
Hydrological phenomena
22 River basin change C
23 Influence on ground water X
24 Flow condition change C
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water quality 25 Water temperature change X
Impact Items Evaluation Reasons
Natural
Environment
26 Eutrophication D
27 Turbid water C
Sediment 28 Sediment component change D
Biosphere Plants 29 Influence on dams X
Animals 30 Influence on animals C Aquatic organisms 31 Influence on aquatic organisms B Ecological system 32 Destruction of ecologic system C
Atmosphere
Air
33 Air pollution X
34 Microclimate change X
Odour 35 Generation of odour substances X
Noise/vibration 36 Occurrence of noise and vibration C Note
A- Serious impact B- Medium level impact C- Slight impact D- Unkwon (Study is necessary. It is also necessary to consider that the Impact may be clarified as the
study progresses) X- Environmental impact by this study does not exist
APPENDIX K: Average Monthly Rainfall (mm) for Kilondo from 1976-1980
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
1976 84.00 90.90 176.00 185.00 114.00 78.50 16.15 12.38 1.14 2.26 32.50 79.38
1977 70.50 137.00 157.00 157.00 100.50 65.00 17.95 1.00 0.00 2.26 187.20 125.30
1978 183.50 128.00 255.00 282.00 213.50 178.00 56.85 0.00 0.00 2.26 115.90 116.90
1979 115.90 185.00 109.00 59.50 145.90 110.00 0.00 0.00 3.87 1.35 86.60 173.20
1980 147.70 88.30 133.00 193.00 177.70 142.00 0.00 0.00 8.23 1.19 22.90 76.78
Average 120.32 125.84 166.00 175.30 150.32 114.70 18.19 2.68 2.65 1.86 89.02 114.31
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Appendix M: Layout of Kilondo Hydropower Plant
Power house House
Tail Race
Abutement
Kilondo River
Weir Forebay Tank
Channel
Penstock
River Crossing
Metres 0 500 1000