Hydropower Resources and Potentials for Renewable Electricity

1. Hydropower Resources andPotentials for RenewableElectricity D. BashirNational Water Resources Institute, Kaduna Presentation at National Workshop on Renewable Electricity For Remote LocationsThree Star Hotel, Dutse on 12th March, 2007

2. Importance of Energy • Energy is vital for the provision of most goods and services • Correlation has been established between sustainable development and availability of reliable and affordable electrical power • Increasing population and quality of life demand increasing energy supply • Major national and international policies and programmes recognise the centrality of energy to sustainable development

3. Importance of Energy… • The conventional methods of energy supply have resulted in devastating environmental problems • Increasing demands for environment friendly and renewable energy systems • Hydropower is recognised as the most important renewable energy source nationally and internationally

4. Impacts of Hydro Power • Climate change due to CO2 emissions is one of the major environmental challenges today. • Renewable energies are the solution to climate change; • SHP can actively contribute to climate change mitigation, e.g. ESHA has shown that: • 1 GWh of electricity produced by SHP allows to • Supply electricity for 1 yr to 250 households in a developed Country • Save 220 tonnes of petrol • Save 335 tonnes of coal • Avoid the emissions of 480 tonnes of CO2

5. Impacts of Hydro Power • SHP contributes to climate change mitigation because: • It is an inexhaustible energy source • It does not produce greenhouse gas emissions • It has a high-energy payback ratio

6. Principles of Hydropower Systems • The potential energy of a flowing water, from a certain level to a lower level, is converted into mechanical energy by directing the water pressure to move a mechanical device • The device is a hydro turbine that converts the water pressure into mechanical shaft power, which is then used to drive an electricity generator

7. Categorization of Hydropower Schemes Aliyu, U.O. (2004). Small Hydropower (SHP) Design: Matching of Supply and Demand. Guide Book on Small Hydropower Development in Nigeria: Planning, Policy and Finance Issues. ECN pp 86-95.

8. Characteristics of Small Hydropower Systems • Decentralised, small demand for power (small industries, farms, households and rural communities) • Distribution network with low voltages (eventually sub-regional grid) • Can be owned by an individual, co-operative or community with semi-skilled workers • Short planning horizons and construction periods with the use of local available materials and skills • Depending on generated power it can have a substantial impact on local standards of living

9. Advantages of Small Hydropower • Continuous availability of power any time demanded, • Environment friendly, • Decentralized power generation and distribution, • Operational costs relatively low, • Technology appropriate (minimal imports), • A solid and durable technology (systems can last for 50 years or more without major new investments).

10. Limitations of Small Hydropower • A site specific technology, • there is always a maximum useful power output available from a given hydropower site, which limits the level of expansion of activities which make use of the power, • River flows often vary considerably with the seasons (power output can reduce to a small fraction of the possible peak output), • lack of familiarity with the technology and how to apply it inhibits the exploitation of hydro resources in some areas.

11. Intake Canal Typical Run-of-the-River Scheme • River flow is not stopped • A portion of flow diverted and delivered to a turbine • Most suited to micro hydro schemes Forebay • River flow is not stopped • It is simple • Can be built locally at low cost • Communities can operate & maintain • More environment friendly Transmission Lines Penstock Powerhouse • Greatly affected by seasonality

12. Typical Storage Scheme • Required a dam to stop river flow and build up a reservoir • Stored water is released and delivered to a turbine • Not greatly affected by seasonality • Less environment friendly • More complex and expensive • Problems of siltation in the reservoir

13. H Q Estimating Water Power Potential • To determine the potential power of water in a river it is necessary to know the flow (Q) in the river and the available head (H) • The flow of the river (m3/s) is the amount of water (m3) which passes a cross section of the river in a given time (s) • Head is the vertical difference in level (m) the water falls down • The potential power (P) available is directly proportional to the head H and the flow Q and is given by P = Q × H × c       c = constant • The constant c is the product of the density of water (ρ) and the acceleration due to gravity (g) P (Watts) = Q x H x (1000 x 9.8) P = 9,800 x Q x H Watts

14. Utilization of Energy from Small Hydropower Schemes

15. Promoting SHP in Nigeria • Energy Commission of Nigeria (ECN) prioritise renewable energy dev., 2 Research Centres • National Energy Policy approved and launched in 2003 • National Energy Masterplan in Final draft • ECN collaborating with UNIDO to promote SHP • Establishment of UNIDO Africa Regional Centre for SHP in Abuja • Promote and support the establishment of a National NGO for SHP (Association of Member of International Network for Small Hydropower (AM-INSHP) • Pilot SHP schemes at Waya Dam, Bauchi State and Ezioha-Ngbowo village , Enugu State

16. Existing Small Hydropower Schemes in Nigeria Source: UNIDO/ECN (2003). Renewable Energy for Rural Industrialization and Dev. In Nig. p81. * Under refurbishment

17. Distribution of PotentialSmall Hydro Sites Source: UNIDO/ECN (2003). Renewable Energy for Rural Industrialization and Dev. In Nig. p82.

18. R.Yobe R. Komadugu-Gana R. Gari Hadejia-Nguru Wetlands R.Hadejia R. K’ Hausa R. Tomas HVIP R. Kano R. Watari R. Katagum R. Dudurun R. Makankari R. Chalawa Challawa Gorge Dam R. Jama’are R. Dingaya KRIP R. Iggi R. Fakate R. Dogwalo Tiga Dam R. Gulka R. Masaya Proposed Kafin Zaki Dam R. Kano R. Gau R. Jimini R. Dan Warra R. Delimi R. Jauro Major Rivers in HJKY Basin NGURU GASHUA HADEJIA JIGAWA STATE KANO STATE KATAGUM YOBE STATE KANO DUTSE BORNO STATE BAUCHI STATE GOMBE STATE BAUCHI JOS

19. Case Study-Background Source: Ukabiala, C.O. (2006). Ebvaro II Small hydropower in Nigeria: A challenge to developing countries. In Esan, A.A. (Ed.) Small Hydropower for Productive Use in Rural Areas. UNIDO-RC-SHP in Africa. pp 32-38. • A micro hydropower scheme (3 kW) • A private initiative – Mr. Christian Oyenekwe, 42 yrs old, a 1986 School Cert. holder, a farmer and village electrician • Located in Evboro II village, Ovia N.E. LGA, Edo State, 45 km west of Benin City • A small farming village, population 400, 55 households • River Ogbovben, a tributary of Osse (Ovia), divides the village into 2, provides the water for the scheme

20. Case Study-The Dam Supported by the concrete culvert (bridge) The dam is made of wood The weir was also made with wood

21. Case Study-The Powerhouse The powerhouse is housed in one of the twin ducted concrete water channels The water channel is the bridge on Ogbovben river which links the two part s of Evboro II village

22. V-Belt Turbine blade Belt Guide Pulley Case Study-The Mechanical System The turbine is a cross-flow type with 7 blades, locally manufactured from a normal flat mild steel sheet It is coupled to a locally manufactured wooden pulley which drives the generator via a belt drive.

23. Case Study-The Electrical System the generator was a converted electric motor

24. Case Study- Transmission/ Distribution Lines The transmission towers were made from bamboo sticks (Pole) while the lines consist of conventional copper conductors The two lines (live and neutral) drawn from the generator were separated by short pieces of sticks

25. Case Study-Project Specifications • Mr. Oyenekwe took 11 yrs (1986-1997) to complete the project • The scheme in operation for 9 yrs (1997 – date) • Minimum annual flow rate (Q) is 1.72m3/s, corresponding stage height (h) is 1.2m • Insignificant flow variations • Project cost estimated at N60,000

26. Case Study-Project Operations • Only 15 out of the 55 houses connected, pressure to expand • 200 watts for each house, 2-point (60w each) lighting and a plug-point (80w) for radio/tv/fan • No tariff collection, consumers just contribute N2,000 monthly for maintenance (barely sufficient) • O&M cost of scheme only N0.92/kwh month

27. Case Study-Lessons Learnt • The need for electricity in rural areas is real (it propelled Mr. Oyenekwe to develop the scheme) • Materials for development of SHP can be sourced locally and are affordable • SHP schemes are not very capital intensive • O & M are relatively cheap and require low technical skills available in rural areas • Great potential to raise the quality of life in the rural areas

28. Targets for Growth ofRenewable Energy Sub-sector Source: ECN (2005). Draft Renewable Energy Master Plan

29. Conclusions • Reliable and affordable energy supply is pre-requisite for sustainable development • Efficient exploitation of renewable energy resources is a priority at national and international agenda • Hydropower is recognised as the most important renewable energy source • There is great potentials for SHP in Nigeria • SHP schemes are most appropriate for rural energy supply • States and Local Governments would need to accord it top priority

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