U N I V E R S I T Y OF NAIROBI S C H O O L O F E N G I N E E R I NG FEB 540: ENGINEERING DESIGN PROJECT 2014/2015 ACADEMIC YEAR

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1 U N I V E R S I T Y OF NAIROBI S C H O O L O F E N G I N E E R I NG DEPARTMENT OF ENVIRONMENTAL AND BIOSYSTEMS ENGINEERING FEB 540: ENGINEERING DESIGN PROJECT 2014/2015 ACADEMIC YEAR PROJECT TITLE: DESIGN OF A MICRO-HYDRO POWER STATION ON RIVER THIBA CANDIDATE NAME: CANDIDATE No.: SUPERVISOR S NAME: OKECH RHODA BELINDA F21/1699/2010 Mr. STEPHEN C. ONDIEKI A Report Submitted in Partial Fulfillment for the Requirements of the Degree of Bachelor of Science in Environmental and Biosystems Engineering, of the University Of Nairobi 4 th MAY, 2015 F21/1699/2010 i

2 DECLARATION I hereby declare that this design project is my original work and has not been submitted for a degree in any other institution of higher learning. Signature. Date.. This design project has been submitted for examination with my approval as the University Supervisor. Signature..... Date F21/1699/2010 ii

3 DEDICATION I dedicate this project to my parents; George Okech and Agnetter Okech for their unending support throughout my academics. I would also like to thank my brother Kevin Ochola who has been my role model and source of inspiration during this whole process. F21/1699/2010 iii

4 ACKNOWLEDGEMENTS I would like to thank The Lord Almighty for His inspiration, guidance and the peace He instilled in me during the design process as it was quite stressful at some point. I would also love to acknowledge the invaluable support of the following; My supervisor Mr. Stephen C. Ondieki for his technical support, guidance and critique during the supervision visits. My parents for their support in form of encouragement and for giving me the resources I needed for completing my project without any hitches. My friend Jacob Mutua, through whom I gained a perspective of the design process. The Department of Environmental & Biosystems Engineering and the entire staff for having been helpful and supportive during the whole design process. Water Resources Management Authority and Kenya Meteorology Department for availing the data I required to use for my design project. F21/1699/2010 iv

5 LIST OF TABLES Table 1 : List of Micro- Hydro Power Systems in the World... 9 Table 2 : Turbine type and their Efficiency Table 3 : Classification of Turbine Table 4: Analyzed Discharge flows for Kutus Waterfall Table 5: Work Programme F21/1699/2010 v

6 LIST OF FIGURES Figure 1: Google Image of the Site... 4 Figure 2: Hydropower Head... 5 Figure 3: Catchment Area... 6 Figure 4: Broad crested weir Figure 5: Typical Settling Basin Figure 6: Typical Micro Hydropower system Figure 7 : Types of Penstock Material Figure 8: Turbine type and Typical Site characteristics Figure 9 : WHO MAPS; Low flow Discharge Figure 10 : Topographical Profile of the site Figure 11: Flow Duration Curve F21/1699/2010 vi

7 LIST OF ABBREVIATIONS RGS River Gauging Station HDPE -High Density Polyethylene PVC - Poly Vinyl Chloride FDC Flow Duration Curve WRMA Water Resources Management Authority F21/1699/2010 vii

8 ABSTRACT This project addresses the problem of inaccessibility of electricity in rural areas. This is due to exorbitant costs related to connection and bills amassed from the use of electricity from the National grid. It focuses on Micro-Hydro Power as a renewable source of energy. This can be used in an off-grid system so as to cut on costs related to electricity from the National Grid. This project consists of five chapters. The first chapter gives a brief history of Hydro-electric power generation and its current development in Kenya. In this chapter, the objectives of the project are highlighted as well as the scope of the project. Site analysis and inventory is also covered here. The second chapter deals with Literature Review. Various forms of energy are discussed here and it Micro Hydro Power Systems are discussed in detail. The following chapter; i.e. Chapter 3 focuses on theoretical framework, and it contains the formulas needed to design the Micro Hydro Power System. Chapter 4 is on the methods and procedures followed to achieve the objectives of the project. It also focuses on generation of design as well as selection of design for the project. Chapter 5 is on Results and Analysis, and this is followed by Conclusion and Recommendations, Work Programme, References and Appendices. F21/1699/2010 vii i

9 Table of Contents 1.0 INTRODUCTION Problem Statement & Analysis Site Analysis and Inventory Overall Objective Specific Objectives Statement of Scope LITERATURE REVIEW MICRO HYDROS Types of Renewable Energy Wind Energy Geothermal Energy Tidal Energy Solar Energy THEORETICAL FRAMEWORK METHODOLOGY Generation of Design Design Selection Data Collection Data analysis and Presentation Determining the head of the river Determining design flow RESULTS AND ANALYSIS Siting the power generating plant Estimating the power generation potential Design of the Structural Components Weir Intake Canal Settling basin/fore-bay Penstock Forces acting on the weir CONCLUSION AND RECOMMENDATIONS F21/1699/2010 ix

10 7.0 WORK PROGRAMME REFERENCES APPENDICES APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX APPENDIX F21/1699/2010 x

11 1.0 INTRODUCTION Rural electrification is a major focus in the world right now. Energy goes a long way in creating jobs and offering many opportunities such as running of new businesses. Rural areas are characterized with poverty, lack of electricity and various amenities. It is mostly known for its stagnating nature in terms of economic development. The main jobs available in the rural areas require manual labor. Economic development is normally observed in the urban areas as opposed to the rural areas. This is the main reason why poverty is related to the rural areas. The poorest groups in the society are often bypassed by economic development and it is quite true for the people in the rural areas. Rural poverty arises from lack of assets, limited economic opportunities, poor education and capabilities as well as disadvantages rooted in social and political inequalities. The livelihood of rural people is shaped by particular set of vulnerabilities in different ways that they are experiencing. Thus, the repertoire of decisions, choices and options that they can pursue are similarly assorted. The lack of access to electricity is normally the cause of disparity between the urban and rural areas in terms of income and employment as well as the unavailability of basic infrastructure and services. Kutus can be described as a rural area, and according to the governance of the country it is mostly the urban areas that have access to electricity. Currently government policies are geared towards rural electrification. Technological advancements allow some of the jobs which are known to be of a drudgery nature to be done with ease with the use of certain machines-which require electricity. This energy crisis calls for a need to adopt technology that would provide alternative sources of power to compensate for diminishing/unreliable supply. Reliance on power provided by fossil fuels, large hydropower and geothermal source is not adequate to meet the rising demand in Kenya especially in the rural areas. Therefore alternative sources of power supply have to be investigated and exploited in potential areas. Electricity has the power to give a face lift to a rural place and help it advance. There are various ways to produce energy to aid in rural F21/1699/2010 1

12 electrification. This includes use of natural resources such as hydro power, wind power, geothermal, solar, and biogas. Hydropower is one of the oldest sources of energy and was used thousands of years ago to turn paddle wheels for purposes such as grinding of grain (Priyantha, 2007) The Greeks used water wheels for grinding wheat into flour more than 2000 years ago. The energy sourced from water was also used to saw wood and power textile mills and manufacturing plants (Priyantha, 2007). In the case of Kutus, hydropower is the perfect choice as it will use available water source from River Thiba to generate the power. Most rivers in Kenya are found in rural areas yet it is these same areas that lack access to electricity. Harnessing hydro power to provide energy has been a major concern. It is necessary to utilize four physical resources to make a major change in Kenya in the energy sector. These are; energy, space, matter and time. Micro hydro falls within the range of small hydro. Distinction can be made between mini hydro plants whose capacity is below 1MW, Micro hydro whose capacity is below 100 kw and Pico hydro whose capacity is below 20 kw (Wim Jonker Klunne, 2007). They each have their own specific technical characteristics. Micro and Pico hydro installations are typically used in developing countries for energy provision to isolated communities, whereas mini hydro tends to be grid connected. Micro and Pico hydro can also differ from mini hydro due to the extended possibility of using local materials and labor, while mini hydro typically involves more traditional engineering approaches and will usually need a heavy access road for delivery of materials and electro-mechanical equipment. The installation of such can provide power to a small town. F21/1699/2010 2

13 1.1 Problem Statement & Analysis The lack of access to affordable electricity in Kutus, Kirinyaga County. In this time and era, electricity is a very crucial factor as it is needed in every sector of the economy. People in the rural areas are at a disadvantage in nearly every aspect of their lives. This energy can be provided from the natural resources within its environment, in this case the use of the available head in River Thiba. In developing countries, rural populations are largely excluded from the national grid. There are many reasons due to this and one of them is poverty; that being that they can t afford to pay for the transmission to their villages. There is also lack of local capacity to design and develop small hydro power schemes for areas sometimes considered too remote. Generally, most of the countries lack specialization to undertake feasibility studies, detailed studies that would include detailed design and costing of the schemes to make a meaningful impact on utilization of small hydro sites. Other reasons include bad governance as the focus is majorly towards the urban areas. This is however changing with devolution. Electricity plays a major role in economic development. There are various economic activities in the rural areas and most of them are done by manual labor which ends up being time consuming. The energy sources they are able to afford e.g. use of kerosene or diesel in small amounts ends up being expensive in the end- the cumulative amount of money spent. No meaningful development can take place without access to modern energy services. Likewise without electricity, extending common democratic norms and values through radio and television will be a very difficult and unaccomplished task. Hence rural electrification is an indispensable factor for socio-economic development of the community. Various benefits accrued from rural electrification are classified into two: quantifiable and nonquantifiable. The quantifiable benefits among others include its industrial, commercial, domestic and agricultural applications. Non-quantifiable however is its effects on socio-political and employment creation for the people including rural populace. The micro hydro power will provide a reliable, affordable, economically viable, socially acceptable and environmentally sound energy alternative for their economic activities/ development activities. F21/1699/2010 3

14 River Thiba will offer an infinite potential to provide sustainable energy to the community of Kutus. The free running water and the available head will aid in rural electrification for the locality of Kutus. Having electricity means the ability to study at night and get an education, set up businesses/factories. Therefore the lack of it is a setback for their development. 1.2 Site Analysis and Inventory Location The location of the site from Google earth image lies on the following coordinates S and E. The micro hydro power generation plant is to be on River Thiba near Kutus Bridge. The site is next to a waterfall. The bridge is the boundary between The Upper Thiba and The Lower Thiba. The river has a head of about 4m as obtained from the River profile in Google Earth. The image is seen below, in Figure 1. Figure 1: Google Image of the Site F21/1699/2010 4

15 The head coupled with the river flow, given it is a perennial river and the given rainfall patterns of the area, would have a substantial power output. The head obtained is the distance between the Fore-bay and the turbine, as shown in the Figure 2. Figure 2: Hydropower Head (Monition, L.N. 1984) The river is in Kirinyaga County, Kenya. I used a Digital Elevation Model Data to obtain the catchment area for River Thiba using BASINS 4.1 software. This is seen Figure 3 and in appendix 2 and 3. F21/1699/2010 5

16 Figure 3: Catchment Area Climate Description of the Catchment Area River Thiba is in Central Kenya and it cuts across Kirinyaga County. The map is attached in appendix 6. The source is Mt. Kenya Forest. The river gauging stations considered were 4DA10 and 4DA11. The annual mean temperature is about 17.7 C for Nyeri Met. Station, and 21.8 C for Mwea experimental station. These were the nearby stations to the site. The mean annual and monthly total rainfall for the catchment area was obtained from Kenya meteorology department. This is seen in appendix 1. F21/1699/2010 6

17 1.3 Overall Objective To design civil components of a micro-hydro power plant as an alternative source of renewable energy Specific Objectives 1. To determine the optimal location for siting the power generating plant 2. To determine flow indices so as to get the flow to be used for the estimation of power. 3. To estimate the power generation potential on River Thiba 4. To design structural components such as weir, intake canal, settling basin cum forebay and penstock 1.4 Statement of Scope The Micro hydropower system design will combine different aspects of already existing designs. These designs will encompass different design parameters of micro hydro power stations in the World. This project is reliant on a Run of The River Scheme (ROR) and thus will focus on the available head of the river. The focus of the study is to focus is in designing technical components of the Micro Hydro Power System rather than the other factors such as the distribution of electricity and other social, financial and environmental implication. The focus is to estimate power generation potential of River Thiba, near Kutus Bridge. The design will use already available hydrological data which will be collected at the WRMA (Water Resources and Management Authority) offices. This will therefore not include the physical activities of hydrological data collection such as run-off determination, stream flow etc. The scope on topographical survey will involve head determination of River Thiba by using Google Earth. The project will focus on design of the weir as the intake, Forebay cum settling basin and penstock. The producing of and conversion of energy in the turbine and generator will not be included in this project, as the focus is to estimate the power that can be produced. However it will include selection of the turbine depending on design flow and head of water. The power to be produced is to not to be fed into the National grid but to be used in an off-grid system for use by the locality. F21/1699/2010 7

18 2.0 LITERATURE REVIEW Hydropower is the most mature and largest source of renewable power. It harnesses the energy of moving water and converts it into mechanical energy by the use of the turbines and finally electricity by the use of a generator for human consumption. The energy of the flow is associated with the gravity energy through natural or artificially created topographic water falls in rivers or through hydraulic conveyance systems, composed by pressurized pipes or penstocks or by mixed hydraulic conveyance system composed of canal and penstocks. Renewable energy refers to energy sources that are continually replenished by nature; in this case water. Hydropower electricity is generated using the energy of moving water. It has been exploited for centuries. In the late 19 th Century, hydropower became a source for generating electricity. This project is an adoption of the already running hydro power projects/stations in the world. Hydropower production offers great flexibility in size and can be used for large base load power plants or small, decentralized electricity generation. Micro and small-scale hydropower systems are the cheapest renewable energy options and can be important reliable components in mini-grid or off-grid projects for rural electrification. Currently hydropower is the most successful form of renewable energy. Kenya has an estimated hydropower potential of about 6000MW. This includes large hydro power stations (capacity of more than 10MW) and small hydro power stations. Of the large power stations, 807MW has been exploited and it accounts for about 50% of installed generation capacity as at 2013 while about 1450MW remains unexploited. There is more than 3000MW small hydro potential, only about 30MW has been developed. With the introduction of the Feed-in-Tariff (FiT) policy in 2008 small-scale candidate sites are expected to be developed to supply villages, small businesses or farms, as well as a grid supply. The Ministry of Energy and Petroleum has carried out feasibility studies for small hydropower stations in tea growing area covering twelve sites with an estimated combined potential generation capacity of 33MW. Feasibility studies are ongoing at 14 other sites and will be expanded to cover other areas and results used for capital mobilization for development as stand-alone systems or to feed to the national grid, (The Energy Bill 2014, Government of Kenya). F21/1699/2010 8

19 Micro hydro falls under the small hydro plants. There are quite a number of small hydro plants in the world. These are; 2.1 MICRO HYDROS Table 1 : List of Micro- Hydro Power Systems in the World Continent No. of Small Hydro plants. Installed Power (MW) Africa Asia Australia & Oceania Europe (without Russia and Turkey) North and Central America South America Total (Janic, 2003) Investing in micro hydro power projects would go a long way. A micro-hydropower project is an economic source of energy and can provide power to a number of homes and communities. Micro hydro power station being a run-of-river (ROR) hydroelectricity generation is different in design and appearance from conventional hydroelectric stations. The conventional hydro power stations rely on dammed water/reservoir to drive the water turbines. The power extracted depends on the volume of water behind the dam and the available head of water. This project doesn t require a reservoir; it however requires an intake which will include a weir and a canal to direct the water to the settling basin/fore-bay and then to the penstock. It relies on a minimal flow of water to be available all year round. F21/1699/2010 9

20 Hydro power is normally termed a renewable energy source due to: Low polluted energy with small environmental impacts. Relevant components of a sustainable development. Inexhaustible energetic sources, in spite of being limited or continued. A suitable location with adequate head needs to be selected for the micro hydro power station. The project s site is in Kirinyaga County, Kutus on River Thiba. The amount of head available and the flow of water is in direct proportionality to the amount of power which can be produced. There are different types of schemes for small hydro power projects. These are: Run-of-river Canal falls Toe of dam Renovation of existing plants The main advantages of developing small hydro compared to other electricity sources are; It saves consumption of fossil, fuel, and firewood. It is self-sufficient without the need of fuel importation. It does not contribute to environment damages by resettlement, as it occurs with large dams and reservoirs. It can be a good private capital investment in developing or developed countries. Reliable and historically proven technology. Water is free and completely renewable through continued rainfall. F21/1699/

21 The system components of a typical run-of-river project comprises of; i. Weir ii. Settling basin iii. Headrace iv. Forebay v. Penstock vi. Power house and Tailrace vii. Turbine i. Weir An artificial obstruction in any watercourse that results in increased water surface level upstream for some, if not all flow conditions. A structure in a river, stream, canal or drain over which free-surface flow occurs. It may also be used variously for control of upstream water levels, diversion of flow and/or measurement of discharge. Figure 4: Broad crested weir (Charles Rickard, R &D Publication WSB-023/HPP) ii. Settling Basin The settling basin is designed to settle suspended silt. The river may carry small particles of sediment which can cause the turbine wear if they are not removed before the water enters the penstock. Sediment may also block the intake or cause the channel to clog up. This is normally done by reducing the speed of the water to let the sediments settle and removing them before they enter the canal. F21/1699/

22 Figure 5: Typical Settling Basin iii. iv. Typical de-sanding basin (Harvey, Micro Hydro Design Manual, 1983) Headrace The headrace canal takes the river flow from the intake to the forebay. Generally, the canal runs parallel to the river at an ever-increasing difference in elevation, which gives the hydropower system its head (Khennas et al., 2000). The canal cross section and alignment should be designed for optimum performance and economy in order to reduce losses due to leakage. Usually, canals are built from combination of cement and mortar, only soil, mixture of stone and mud, mixture of stone masonry with cement and other different types of possible combinations (Pandey V., 2011). An open channel or pipeline (generally of HDPE-High Density Polyethylene type can be used to transport the water into the fore-bay. Forebay The Forebay tank connects the headrace and the penstock, serving mainly to balance the water from the headrace. It also allows particles to settle down before the water enters the penstock. A trash rack is normally installed at the penstock inlet to prevent floating debris from entering and damaging the turbines. The water level is also determined at the Forebay as the operational head of the micro hydro power is determined through this. F21/1699/

23 v. Penstock The penstock is the pipe which transports water under pressure from the weir directly to the turbine. HDPE (High Density Polyethylene), PVC (Poly Vinyl Chloride) and Steel are usually used as penstock material. These can be installed either above or below the ground vi. Power house and Tailrace The powerhouse is a building that houses the turbine, generator and control units. (Nigel, 1994). The powerhouse is normally a simple structure with a solid foundation. The tailrace is a channel leading away from the powerhouse and turbine. The water is discharged into the tailrace after it has been used for power generation. The channel then leads the discharged water back to rejoin the original river. vii. Turbine A turbine converts the energy of falling water into shaft power. There are various types of turbine which can be categorized in one of several ways. The choice of turbine will depend mainly on the pressure head available and the design flow for the proposed small hydropower station. The maximum output of turbine in watts is calculated using equation below; P maxoutput = ρghqη maxturbine Where; η maxturbine, is the maximum turbine efficiency. The tables below give the variation of turbines with efficiency and classification of turbine according to head for small hydro power. F21/1699/

24 Variation of Turbine Types with Efficiency Table 2 : Turbine type and their Efficiency Turbine(Prime mover) Efficiency Pelton 80-90% Turgo 80-95% Cross-flow 65-95% Propeller 80-95% Kaplan 80-90% (Harvey, Micro-hydro Design Manual 1983.) The table below indicates the different classifications according to available head for small hydro power. (Harvey, Micro-hydro Design Manual 1983.) Different Classification of Turbine According to Head for small hydropower Table 3 : Classification of Turbine Head Classification High (>50m) Medium (10-50m) Type of Turbine Impulse Pelton, Turgo Cross flow, Turgo, Multi-jet Pelton Reaction Francis (spiral case) Low (<10m) Cross flow Propeller, Kaplan, Francis (Open Flume F21/1699/

25 Below is an image of a typical Micro-hydropower system. Figure 6: Typical Micro Hydropower system (Pandey B., 2006) 2.2 Types of Renewable Energy Wind Energy Wind is air in motion. It is caused by the uneven heating of the earth s surface by the sun. The earth s surface is made up of different types of land and water and thus it absorbs the sun s heat at different rates. During the day, the air above the land heats up quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air rushes in to take its place, creating winds. At night the winds are reversed because the air cools more rapidly over land than over water. Wind is used to produce energy by use of wind turbines. The wind turbine collects the kinetic energy of the wind by turning (thus-mechanical energy). A generator is normally connected to the turbines which converts the mechanical energy to electrical energy. Wind energy is termed as renewable as it does not run out. It is continuously replenished by nature. F21/1699/

26 2.2.2 Geothermal Energy The word geothermal comes from the Greek words geo earth) and therme (heat).thus geothermal energy is heat from within the earth. Geothermal energy is termed as renewable energy because the water is replenished by rainfall and the heat is continuously produced within the earth. Geothermal energy is generated in the earth s core, about 4000 miles below the earth s surface. Very high temperatures are produced by the slow decay of radioactive particles; a process that occurs in all rocks. Geothermal energy can sometimes find its way to the earth s surface in the form of; Volcanoes and fumaroles Hot springs Geysers When magma comes close to the surface it heats groundwater found trapped in porous rock or water running along fractured rock surfaces and faults. This is then released to the surface as high-pressured steam. The most active geothermal resources are usually found along major plate boundaries where earthquakes and volcanoes are concentrated. Most of the geothermal activity in the world occurs in an area called The Ring of Fire. This are borders the Pacific Ocean. Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs; as in the case in Olkaria. Geologists use various methods to look for geothermal reservoirs. Drilling a well and testing the temperature underground is the only way to be sure a geothermal reservoir exists. There are three basic types of geothermal power plants; Flash Steam Plants: These plants take high hot water pressure from deep inside the earth and convert it to steam to drive the generator turbines. When the steam cools, it condenses to water and is injected back to the ground and is used over and over again. F21/1699/

27 Dry Steam Plants: Dry steam plants use steam piped directly from a geothermal reservoir to turn the generator drives. The first geothermal power plant was built in 1904 in Tuscany, Italy. It was a place where natural steam was erupting from the earth. Binary Power Plants: In Binary power plants, heat is transferred from geothermal hot water to another liquid. The heat causes the second liquid to turn to steam which is used to drive a generator turbine. It then condenses back to its liquid state and is used again Tidal Energy Tidal energy is a form of hydropower that converts the energy of tides into electricity or other useful forms of power. Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Tidal power is the only form of energy which derives directly from the relative motions of the Earth-Moon system, and to a lesser extent from the Earth-Sun system (Pamedo, 1978). The tidal forces produced by the Moon and Sun, in combination with the earth s rotation, are responsible for the generation of tides. Because the earth s tides are caused by tidal forces due to gravitational interaction with the moon and the sun, and the earth s rotation, tidal power is practically inexhaustible and classified as a renewable energy source. A tidal energy generator uses this phenomenon to generate energy. The stronger the tide, either in water level height or tidal current velocities, the greater the potential for tidal energy generation. Tidal movement causes a continual loss of mechanical energy in the Earth-Moon system due to pumping of water through the natural restrictions around coastlines, and due to viscous dissipation at the sea bed and in turbulence (Pamedo, 1978). This loss of energy has caused the rotation of the earth to slow in the 4.5 billion years since formation. During the last 620 million years the period of rotation has increased F21/1699/

28 from 21.9 hours to the 24 hours we see now; in this period the earth has lost 17% of its rotational energy. While tidal power may take additional energy from the system, increasing the rate of slow down, the effect would be noticeable over millions of years only, thus being negligible Solar Energy Solar energy is the conversion of sunlight energy into electricity. To do this, a photovoltaic cell is needed to convert solar energy directly into electrical power. It is also known as a PV or a solar cell. Sunlight is composed of photons. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photo-voltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight energy is absorbed by the material (normally a semi-conductor), electrons are dislodged from the material s atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons, so the electrons naturally migrate to the surface. When the electrons leave their position, holes are formed. When many electrons, each carrying a negative charge, travel toward the front surface of the cell, the resulting imbalance of charge between the cell s front and back surfaces creates a voltage potential like the negative and positive terminals of a battery. When the two surfaces are connected through an external load, electricity flows. The photovoltaic cell is the building block of a solar energy/photovoltaic system. One cell normally produces 1 or 2 watts, which isn t enough power for most applications. To increase power output, cells are electrically connected into a packaged weather tight module which can be further connected to for an array. Array refers to the entire generating plant, whether it is made up of one or several thousand modules. The number of modules connected together in an array depends on the amount of power output needed (Kadete et al., 1978) The performance of a photovoltaic array is dependent upon the sunlight. Climate conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy F21/1699/

29 received by a photovoltaic array and, in turn, its performance. Most current technology photovoltaic modules are about 10% efficient in converting sunlight. The simplest photovoltaic systems power many of the small calculators as well as wrist watches. More complicated systems provide electricity to pump water, power communications equipment and even provide electricity to our homes. Some advantages of photovoltaic systems are; Conversion from sunlight to electricity is direct, so that bulky mechanical generator systems are unnecessary. PV arrays can be installed quickly and in any size required or allowed. Low running costs. Infinite energy resource. The environmental impact is minimal, requiring no water for system cooling and generating no by-products. Photovoltaic cells, like batteries, generate direct current (DC) which is generally used for small loads (electric equipment). When DC from photovoltaic cells is used for commercial applications or sold to electric utilities using the electric grid, it must be converted to alternating current (AC) using inverters, solid state devices that convert DC power to AC. F21/1699/

30 3.0 THEORETICAL FRAMEWORK 1. Determining the flow duration curve. This included use of hydrological data of River Thiba. Weibull formula was preferred compared to Californian method which is; P = m. N This formula is not preferred as it shows a 100% probability of a flow being equaled or exceeded which is not feasible or guaranteed. The Weibull formula shown below eliminates the error experienced in Californian method. P m = m N+1 (1) Where Pm is the probability that the position with rank m is equaled or exceeded N is the number of observations m is the number of times a certain value has been equaled or exceeded. Plant flow capacity should be developed with reference to the flow duration curve (FDC) of the river. The following preliminary criteria are suggested; For isolated plants: QP = Q90% For grid connected plants: QP = Q35% Where: QP = plant flow capacity (m3/s). QT% = flow equaled or exceeded T% of time (the Gaia foundation, 2013) F21/1699/

31 2. Designing the system components; i. Weir Weirs are overflow structures built across open channels to measure volumetric flow of water or to be used as an intake. In the design of the weir the following will be considered: This will include determining the height and width of weir. The height and width of the weir will be dependent on the volume of the pool of water you need behind the weir to submerge the intake-in my case, a canal which serves as an intake to the settling basin cum Forebay. ii. Intake Canal A concrete canal will be constructed at the side of the weir and it will be used as a side intake. It is to be submerged by the pool of water behind the weir so as to avoid air pockets. The type of canal that will be used will be a rectangular channel. The first thing needed is to determine; The cross-sectional flow area of the canal. This is given by; Q = A * V (1) Where; Q = Design flow in (m 3 /s) A = cross-sectional flow area of the canal in(m 2 ) V = Channel velocity in (m /s) Optimum height of canal (H) H = A ( X+N) (2) Where; A = cross-sectional flow area of the canal X= 2 (1 + N 2 ) 2 N ; factor used to optimize the shape of the canal. F21/1699/

32 N = the side slope of the canal Optimum width of canal bed ( B ) B = X * H (3) Optimum width of the top of the canal (T) T = B + (2 * H * N) (4) Critical Velocity To ensure that the water flows in a stable and uniform flow in the canal, the velocity of water must be 80% less than the critical velocity where critical velocity (V c ) is; V c =( A g T ) (5) A = cross-sectional area of canal g=gravity T = Width of canal top Wetted perimeter(p) P = B + (2*H) (6) Hydraulic radius (R) R = A/P (7) Slope of the canal (S) The slope of the canal is determined by using manning s equation which is sated below; Q = V * A = ( 1 2 )* A * R 3 * S (8) n Q = design flow (m 3 /s) V = channel velocity A = cross sectional flow area n = Manning s roughness co-efficient for the channel R = hydraulic radius S = channel slope F21/1699/

33 iii. Head loss This is determined by; Head loss = L * S (9) Where; L = Length of the canal section S = slope of the canal To allow for uncertainties in the canal: a) Free board of 300mm if design flow is less than 0.5 m 3 /s b) Free board of 400mm if design flow is in between 0.5m 3 /s and 1m 3 /s Settling basin/forebay Width of settling basin Rule of thumb dictates the width of the settling basin should be 2 to 5 times larger than that of the canal taking water to it. It can be made as wide as possible depending upon the available width of Micro Hydro Project Site. Pandey B., 2006). Length of the settling basin Length of the settling basin is given by the equation below; L settling = (2 * Q) / (W * V vertical ) (10) Where; Q = design flow (m 3 /s) V vertical = fall velocity W = width of settling basin Silt load S load = Q * T * C (11) Where; S load = Silt load (kg) Q = discharge for the flushing canal. T = silt emptying frequency in seconds.12hours * (Pandey B., 2006). C = silt concentration of incoming flow ( kg/m 3 ) Thus, Volume of the silt load is; F21/1699/

34 Volume silt = Where; S load S density Pfactor S density= Density of silt (2600 kg/m 3 is generally used) P factor = packing factor of sediments submerged in water-0.5 is generally used. D collection = Volume silt L settling W Where; D collection = Average depth required for sediment storage N/B: Design of the settling basin is similar to that of the fore-bay tank. The only contrary is that the fore-bay is connected to the penstock. Generating electricity using micro hydropower system doesn t require as much components, thus the settling basin is combined with the fore-bay so as to have one structure. Thus the name settling basin cum fore-bay. Submergence head This is the depth of water above the penstock pipe. This is important as it prevents pockets of air in the pipe/ air from entering the pipe which often leads to explosion of penstock pipes. The submergence head should be big enough to avoid entry of unwanted air in the pipes. The equation below is normally used to calculate the submergence head. Hs 1.5 V 2 /2g (12) Where; V= flow velocity in the penstock Hs = submergence head Flushing Canal The flushing canal is used to flush out the sediment stored in the settling basin from time to time. The formula below is used to determine the diameter of the canal that will be used for that. F21/1699/

35 Q discharge = C * A * 2 g H (13) Q discharge = Discharge flow for the flushing canal C = Co-efficient of discharge A = Area of the orifice H = height of the orifice g= gravity iv. Penstock Several factors are considered when it comes to selecting the penstock material of to use. Mild steel and HDPE-High Density Polyethylene are normally used in Micro Hydro Power Projects. There are several factors to be considered when it comes to selecting the material to be used. The table below illustrates shows different kinds of materials to use based on various factors. Figure 7 : Types of Penstock Material Cost will determine the material of the penstock to use. Determining the penstock diameter is also essential. The penstock diameter, d, in metres can be computed as shown below Q = V A V π D Where; Q = 4 F21/1699/

36 Therefore; the diameter D is; 4 Q D = π V (14) Where Q = the discharge rate of flow (m 3 /s) V = the velocity of flowing water (m/s) D = inside diameter of the pipe A = cross-sectional area Head loss It is also important to calculate the head loss in the penstock. This is given by; Where; h f = f L V2 2 g D h f = Major head loss f= friction factor for pipe material L = length of pipe in metres V = average velocity inside pipe D = inside diameter of the pipe f = Determine friction factor (log k e ( 3.7D Re f = friction factor k = roughness height D = inside diameter of the pipe Re = Reynolds number Re = 4 V R ν V = average velocity R = hydraulic radius ν = kinematic viscosity v. Turbine (15) 0.9) ) 2 (16) (17) F21/1699/

37 Although this study is not concerned with the functioning parameters of the turbines, it is relevant to select one for the project depending on the parameters involved such as design head and discharge. Crossflow turbines are normally used for low to medium flows, about 0.1 5m 3 /s. Kaplan turbines are normally used for flows of about 3 30m 3 /s. This is seen in Figure 9 below. Figure 8: Turbine type and Typical Site characteristics F21/1699/

38 vi. Power Estimation The formula to be used in determining the power potential is; The power equation applied to a conventional hydro-power plant is also applied to SHP. The power available at the generator output P output watts is given by equation below; P output = P gross η (20) Where P gross is the gross power in watts η is the overall efficiency of the hydropower scheme. The gross power is the product of the gross head (H) in metres, the design flow Q in m3/s and a coefficient factor that is the acceleration of free fall g in m/s 2. Hence, we have: P gross = ρghq Where is g assumed 9.81m/s2 The use of equation (2) in equation (1) yields: P output = ρghqη Where η = η civil work η penstock η turbine η generator η drive system η line η transformer However given the efficiencies of turbine and generator preference over others as the major determinants of the available power from small hydropower scheme, equation 3 can be modified as; P output = ρghqη turbine Turbine efficiency is read from Table 2 above. F21/1699/

39 4.0 METHODOLOGY 4.1Generation of Design Preliminary review of the site was carried out to determine the feasibility of the project. First hand data was collected to determine the feasibility of the project. This include determining the topographical nature of the area using google earth. Data from selected literature pertaining to this project was required so as to be able to come up with the most appropriate design for the project. This also included technical parameters of the project to be considered. The literature was available online from research papers and e-books; this created a perspective of how micro-hydro projects are or should be. 4.2 Design Selection This was determined from the data collected as well as the literature review. There are various designs of micro-hydro projects, the conventional one includes; Weir intake Forebay Headrace Settling Basin Penstock Powerhouse and its components. The design of this project was however manipulated and its components include; Weir A side intake, a rectangular channel Forebay cum settling basin Penstock This was done so as to maintain the head of water available. If the conventional method was used, a head of 2m would have been lost, and this would reduce the power that could be produced. An AutoCAD design of the fore-bay cum settling basin and rectangular channel is attached in appendix 7 F21/1699/

40 4.3 Data Collection This involved collecting hydrological data from Water Resources and Management Authority (WRMA). The relevant River Gauging Stations (RGS) for the particular site was obtained from the map below. Figure 9 : WHO MAPS; Low flow Discharge The river flow daily data of the relevant RGS stations, i.e. 4DA10 and 4DA11 was obtained from WRMA offices. 4DA10 daily discharge was ranging from , while 4DA11 discharge data was ranging from The rainfall data of the area was collected from Meteorology Department. The hydrological data of the average river flows is attached in the appendix 4 and appendix 5. F21/1699/

41 4.4 Data analysis and Presentation Determining the head of the river The head of the river from the Micro Hydro literature is the distance between the Forebay and the powerhouse. This profile is obtained from google earth and this is shown in the image below. Figure 10 : Topographical Profile of the site. The Forebay is to be situated at 1273m and the powerhouse at 1269m. Thus the head obtained is 4m Determining design flow 1. A flow duration curve was developed to get the whole scope of the power potential. It shows how flow varies throughout the year and how many months in a year that a certain flow is exceeded or equaled. The curve was obtained by; a) Arranging the flow values (daily discharge values) in the available period of record i.e. 38years for 4DA10 and 25 years for 4DA11 in the ascending order F21/1699/

42 of magnitude and the number of occurrences of each flow value or range of flow values. b) From this the number of times and the percent of time each flow value or range of flow values had been equaled or exceeded in the period of record was obtained. c) The duration curve is constructed by plotting each flow value against the percent of time it had been equaled or exceeded. The flow duration curve is the basis of the project as it is useful in that the power that can be generated can be superimposed onto it so that it is possible to calculate the time in a year that certain power levels can be obtained. The flow indices to be used for the power generation will be determined from the flow duration curve. The equations to be used to obtain the flow duration curve are in equation 1, in the theoretical framework. For power production, flow index Q90 was considered. Q90 means that a certain flow value in the river will be equaled or exceeded 90% of the time in a particular year and can thus be used for power production. It has a 10% probability of failure in a particular year. The FDC curve for the micro hydropower site, was found by interpolating between the two sets of data, i.e. data for RGS 4DA10 and 4DA11. The site is near a waterfall The table below shows the analyzed data used to determine the flow duration curve. F21/1699/

43 Table 4: Analyzed Discharge flows for Kutus Waterfall Probability of exceedance Q, flow discharge in m 3 /s F21/1699/

44 Q Figure 11: Flow Duration Curve FDC for Kutus Waterfall % probability of exceedance From the graph; To get the design flow, Q90 is read from the graph. Q90 = m 3 /s F21/1699/

45 5.0 RESULTS AND ANALYSIS The following procedures will be followed so as to achieve the set objectives for this project. 5.1 Siting the power generating plant The site was selected using google earth. Google earth was used to determine an optimal site by looking at differential heads at different points on the river. The optimal head available at the area of study was selected as the optimal site. The site is near Kutus town, i.e. River Thiba; and it is restricted to the river bed which covers a distance of approximately 78.1m. The site is next to the waterfall on the river The image below shows the site and the river profile of River Thiba which is obtained from Google Earth as well. This is seen in figure 1 above. 5.2 Estimating the power generation potential. The formulas below will be used P output = P gross η Where; P gross = ρghq g = gravitational force ρ = density of water H = head of river Q = Flow of the river (m 3 /s) Data required for this project include; a) River flow b) River profile. F21/1699/

46 The flow of the river Q was be obtained from the flow duration curve obtained above and it is found to be m 3 /s. The river profile was obtained from Google earth, as stated above. This was be used to obtain the required head; H, to be used for power production. The head obtained was 4m Thus; P output = = watts Gross Power = kW 5.3 Design of the Structural Components Weir The weir used in this micro hydro is a broad crested weir which is basically a wall across the river. The weir in this case is used primarily to create a pool of water behind the weir. The pool of water is needed so as to submerge the intake canal so as to avoid entry of air. The weir length was determined by measuring the width across the river s site on google earth. Length = 16.6m + 1m = 17.6m The 1m accounts for additional 0.5m on both sides of the bank of the river. Height of the weir was chosen arbitrarily as 0.6m, it is the standard height required to create a pool of water needed behind the weir. Area behind the weir (where the pool of water is needed) was determined from google earth and it was determined to be = 127 m 2 The volume of the pool of water behind the weir was thus determined as; = 127 * 0.65 = m 3 /s F21/1699/

47 5.3.2 Intake Canal The intake canal/channel is chosen to be a rectangular channel. It is to be made of mass concrete. The velocity is thus taken as 2m/s The cross-sectional flow area of the canal. This is given by; Q = A * V Where; Q = Design flow = (m 3 /s) A = cross-sectional flow area of the canal in(m 2 ) V = Channel velocity in (m /s), which is taken as 2. 95m /s A = = m2 Optimum height of canal (H) H = A ( X+N) Where; A = cross-sectional flow area of the canal = N = the side slope of the canal = 0; as the canal is a rectangular channel X= 2 (1 + N 2 ) 2 N ; factor used to optimize the shape of the canal. X= 2 ( ) 2 0 = 2 Thus, H = ( 2+0) = m Optimum width of canal bed ( B ) B = X * H B = 2* B = m F21/1699/

48 Optimum width of the top of the canal (T) T = B + (2 * H * N) T = (2 * * 0) T = m Critical Velocity To ensure that the water flows in a stable and uniform flow in the canal, the velocity of water must be 80% less than the critical velocity where critical velocity (V c ) is; V c = ( A g T ) A = cross-sectional area of canal g=gravity T = Width of canal top V c = ( V c = 6.458m/s ) 0.8V c = 5.166m/s 2.95 m/s velocity of water in the intake canal is less than 0.8V c ; thus the 2.95 m/s is acceptable for the design of the canal. Wetted perimeter(p) P = B + (2*H) P = (2*0.6583) P = m Hydraulic radius (R) R = A/P R = / R = F21/1699/

49 Slope of the canal (S) The slope of the canal is determined by using manning s equation which is sated below; Q = V * A = ( 1 2 )* A * R 3 * S n Q = design flow = m 3 /s V = channel velocity A = cross sectional flow area = m 2 n = Manning s roughness co-efficient for the channel=0.013 R = hydraulic radius= S = channel slope = ( )* * * S S = Head loss This is determined by; Head loss = L * S Where; L = Length of the canal section = 5.02m S = slope of the canal = Head loss = 5.02 * Head loss = m To allow for uncertainties in the canal: Free board of 500mm if design flow is more than 1 m 3 /s F21/1699/

50 5.3.3 Settling basin/fore-bay Width of settling basin Rule of thumb dictates the width of the settling basin should be 2 to 5 times larger than that of the canal taking water to it. W = * 4.5 W = m Length of the settling basin Length of the settling basin is given by the equation below; L settling = (2 * Q) / (W * V vertical ) Where; Q = design flow (m 3 /s) V vertical = fall velocity W = width of settling basin For a particle size of 0.3mm, the fall velocity is taken as 0.03m/s L settling = (2 * ) / ( * 0.03) L settling = m # An extra 3m for the tapering entrance of the basin to avoid turbulence Thus the total length would come to 31.77m Silt load S load = Q * t * C Where; S load = Silt load (kg) Q = design flow t = silt emptying frequency in seconds.12hours * (Pandey B..,2006). C = silt concentration of incoming flow ( kg/m 3 ) In the absence of reliable data, C is taken as 0.5kg/m 3 S load = * * 0.5 S load = kg Thus, Volume of the silt load is; F21/1699/

51 Volume silt = Where; S load S density Pfactor S density= Density of silt (2600 kg/m 3 ) is used in the absence of reliable data. P factor = packing factor of sediments submerged in water-0.5 is generally used. Volume silt = Volume silt = m 3 Depth of collection D collection = Volume silt L settling W Where; D collection = Average depth required for settling of sediments D collection = D collection = 0.249m N/B: Design of the settling basin is similar to that of the fore-bay tank. The only contrary is that the fore-bay is connected to the penstock. In this project the settling basin is combined with the fore-bay so as to have one structure. Thus the name settling basin cum fore-bay. Submergence head This is the depth of water above the penstock pipe. This is important as it prevents pockets of air in the pipe/ air from entering the pipe which often F21/1699/

52 leads to explosion of penstock pipes. The submergence head should be big enough to avoid entry of unwanted air in the pipes. The equation below is normally used to calculate the submergence head. Hs 1.5 V 2 /2g Where; V= flow velocity in the penstock, which is taken as 2.95m/s Hs = submergence head Hs = 1.5 * /2*9.81 Hs = 0.665m Height of settling basin/forebay Submergence head + diameter of penstock + height of penstock above slab = 2.265m Flushing canal Q = C * A * 2 g H The equation can be rewritten as; Q = C * (π *( H ) 2 ) * 2 g H 2 Q, discharge = 0.04 Coefficient of discharge, C = = 0.6 * (π *( H ) 2 ) * 2 g H 2 H = 0.2 Diameter of canal = 0.2m F21/1699/

53 5.3.4 Penstock Determining the penstock diameter is also essential. The penstock diameter, d, in metres can be computed as shown below; Q = V A Where; Q = V π D 4 Therefore; the diameter D is; 4 Q D = π V Where Q = the discharge rate of flow m 3 /s V = the velocity of flowing water 2.95m/s D = inside diameter of the pipe A = cross-sectional area D = π 2.95 = 1.05 m Head loss It is also important to calculate the head loss in the penstock. This is given by; Where; h f = f L V2 2 g D h f = Major Head loss f= friction factor for pipe material L = length of pipe in metres = 38.31m V = average velocity inside pipe = 2.95m/s D = inside diameter of the pipe = 1.05 F21/1699/

54 Determine friction factor f = (log e ( f = friction factor k 3.7D ) 2 Re 0.9) k = roughness height D = inside diameter of the pipe Re = Reynolds number Re = 4 V R ν V = average velocity R = Hydraulic radius ν = kinematic viscosity Average velocity = 2.95m/s Hydraulic radius, R = Area/ Wetted Perimeter Area of the pipe = π * ( ) = m 2 Wetted perimeter = π * 1.05 = m Hydraulic radius (R) = (0.8666/3.2987) = ν = kinematic viscosity of water at 20 is m 2 /s Therefore; Re = = Re = (unit less) D = 1.05m k = roughness height for plastic is m f = ) (loge ( ) f = Thus, Head loss, h f = F21/1699/

55 h f = 0.253m The generated power after accounting for head loss is; Head = = P output = P output = watts P output = kW Forces acting on the weir Water depth above weir Crest width H1 Weir height V2 V3 H4 H3 H2 V1 Base height U2 Base width U1 F21/1699/

56 HORIZONTAL FORCES Force of Water upstream Horizontal pressure at the bottom = (Weir height + water level above weir crest)*weight of water Weight of water = 10.00KN/m 3 P1= ( )*10 = 8 KN/m2 Force over the height = (Horizontal pressure*(weir height + water level above weir crest) H1 = (8 / 2)*( ) = 3.2 KN/m Distance to the toe = (weir height + water level above weir crest) / 3 ( ) / 3 = 0.27 m Moment about the toe of the weir Force over the height * Distance to the toe 3.2 * 0.27 = KN/m F21/1699/

57 Forces of sediment upstream Horizontal pressure at the bottom = weir height *neutral soil pressure co-efficient * (Weight of saturated soil - weight of water) P2 = 0.6 * 0.5 * (20-10) P2 = 3 KN/m2 H2= (average of minimum and maximum pressure) * weir height (3 + 0/2) * 0.6 H2 = 0.9 KN/m2 The distance to the toe = (weir height) / / 3 Distance to toe = 0.2m Moment about the toe of the weir Force over the height *Distance to toe 0.9 * 0.2= 0.18 KN/m Total of horizontal moments = = 1.044KN/m VERTICAL FORCES V1 Bottom width * base height *mass concrete unit weight 1 *0.2*24 V1 = 4.8 KN/m F21/1699/

58 Distance to the toe = (bottom width) / 2 = 1/2 = 0.5 m Moment about the toe of the weir Vertical force * distance to the toe 4.8 * 0.5 = 2.4 KN/m V2 Crest width *(weir height - base height) *mass concrete unit weight V2= 0.5 * ( ) * 24 = 4.8 KN/m Distance to the toe = (bottom width - crest width) + (crest width /2) (1-0.5) + (0.5 / 2) = 0.75 m Moment about the toe of the weir Vertical force * distance to the toe 4.8 * 0.75 = 3.6 KN/m V3 (Bottom width - crest width) /2)* ( weir height - base height) *mass concrete unit weight = ((1-0.50) /2) * ( ) *24 V3 = 2.4 KN/m Distance to the toe = (bottom width - crest width) * 2/3 (1-0.50) *2/3 = m Moment about the toe of the weir Vertical force * distance to the toe 2.4 * = 0.8 KN/m F21/1699/

59 UPLIFT UPSTREAM Uplift pressure = - (weir height + water level above weir crest) * weight of water P3 = - ( ) * 10 = - 11 KN/m The average force = ((uplift pressure upstream + uplift pressure downstream) /2) * bottom width = ( /2) * 1 = -5.5 KN/m Distance to the toe = 1 * 2/ m Moment about the toe of the weir Force * distance to the toe -5.5 * = KN/m Total of vertical moments = ( ) = 3.133KN/m OVERTURNING Overturning will be looked at around the downstream the toe of the weir. a) Ratio of vertical moments to horizontal moments The ratio should be larger than 1 but for safety reasons taken as 1.5 Vertical moments = = 3 Horizontal moments The weir is stable against overturning since the ratio is larger than 1.5. F21/1699/

60 6.0CONCLUSION AND RECOMMENDATIONS The objectives of the design project were met. The design project could be adopted by students in the lower classes for learning purposes. 7.0 WORK PROGRAMME Table 5: Work Programme ACTIVITY OCTOBER NOVEMBER DECEMBER JANUARY FEBRUARY MARCH APRIL MAY Concept note & Concept Paper Developme nt Proposal Developme nt Data Collection Data Entry & Analysis AutoCAD Design Report Writing& Project F21/1699/

61 8.0 REFERENCES Chanson, H. (2004). "The Hydraulics of Open Channel Flow : An Introduction." Butterworth-Heinemann, Oxford, UK, 2nd edition. Charles Rickard; R&D Publication WSB-023/HPP Gonzalez, C.A., and Chanson, H. (2007). Experimental Measurements of Velocity and Pressure Distribution on a Large Broad-Crested Weir, Flow Measurement and Instrumentation. Grumman, H., (1978). Mean velocity of flow water in open channels, St. Lous. Harvey A. & Brown A. (1992). Micro-hydro Design Manual, ITDG Publishing. Harvey, Micro hydro Design Manual, (1983) Henderson, F.M. (1966). "Open Channel Flow." MacMillan Company, New York, USA. Kadete, H. & Reichel, R., (1978). Experiences with small hydro power stations in Tanzania, Dar es salaam. Khennas, J.K, Smail, A.M and Barnett A. (2000). Best practices for sustainable development of micro hydro power in developing countries, World Bank/ESMAP Kuntz, H., (1979). Hydro-electric power: Rural electrification through isolated systems Masters, G. M. (2004). Renewable and Efficient Electric Power Systems. Wiley Interscience. Nottingham Trent University (2007). Pico Hydro for village Power A Practical Design and Installation Manual for Schemes up to 5kW in hilly and mountainous areas. Pamedo, P.F., et al., (1978). Energy needs uses and Resources in Developing Countries, U.S. A.I.D Springfield. Pandey, B. (2006). Micro Hydro System Design. (www. binodpandey.wordpress. com). F21/1699/

62 Pandey, V. (2011). Research report on feasibility study of micro hyrdopower in Nepal. Bhaktapur: Nepal Engineering College. Priyantha, D.C. (2007). Best Practices for Micro-Hydro Development Sturm, T.W. (2001). "Open Channel Hydraulics." McGraw Hill, Boston, USA, Water Resources and Environmental Engineering Series, 493 pages. The Energy Bill 2014, Ministry of Energy Kenya Vogel, RM and Fennessey, NM Flow-Duration Curves. I. New Interpretation Intervals, J. Water Resources Planning and Management. Wakil M.M.EL (1989). Power Plant Technology. McGraw Hill Book co., New York. Wim Jonker Klunne, (2007). Small hydropower development in Africa World Bank, (1980). Energy in developing countries, Washington D.C. Yüksek, Ö and Kaygusuz, K Small hydropower plants as a new and renewable energy source. Energy Sources. F21/1699/

63 9.0 APPENDICES 9.1 APPENDIX 1 F21/1699/

64 9.2 APPENDIX 2 F21/1699/

65 9.3 APPENDIX 3 F21/1699/

66 9.4 APPENDIX 4 RGS 4DA10 MONTHLY DISCHARGE Year Column Lab Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Grand Total Grand Tot F21/1699/

67 9.5 APPENDIX 5 Sum of 4DA11-Thiba-Discharge [m3/s] Column Labels Row Labels Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Grand Total Grand Total F21/1699/

68 9.6 APPENDIX 6 F21/1699/

69 9.7 APPENDIX 7 F21/1699/