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Geothermal Energy

Geothermal Energy. The Indigenous, Renewable, Green Option. Dr. Silas M. Simiyu Geothermal Development Kenya Electricity Generating Company LTD P.O Box 785, Naivasha Kenya. Presentation outline. Introduction Geothermal Development Process Principles of Operation

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Geothermal Energy

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  1. Geothermal Energy The Indigenous, Renewable, Green Option Dr. Silas M. Simiyu Geothermal Development Kenya Electricity Generating Company LTD P.O Box 785, Naivasha Kenya

  2. Presentation outline • Introduction • Geothermal Development Process • Principles of Operation • Status and development potential in Africa • Stages in Geothermal Development • Barriers to Geothermal development in Kenya • Conclusions

  3. World Wide Location Geothermal power plants • In the middle of crops • In forested recreation areas • In fragile deserts • In tropical forests • In game parks with fragile ecosystems • In high population areas

  4. Benefits of Geothermal Energy • Provides clean and safe energy using little land • Is renewable and sustainable • Generates continuous, reliable “baseload” power • Conserves fossil fuels and contributes to diversity in energy sources • Avoids importing and benefits local economies • Offers modular, incremental development andvillage power to remote sites

  5. Geothermal and the Environment • Geothermal energy is clean energy and renewable • Geothermal power stations emit less greenhouse gases compared to other sources of energy Emissions (kg/MWhr). From Reed and Renner, 1995

  6. WHAT IS GEOTHERMAL • Geothermal Energy heatfrom the Earth Transmitted: • Conduction • Convection • fluids via fractures and pores in the rocks

  7. Geothermal Fields of the World

  8. Rift Based Geothermal Model

  9. Manifestations Geysers Hot Springs Fumaroles Hot Ground Sulfur

  10. Geothermal Development Process: Kenya’s Examples

  11. Geothermal Development processStage I: Exploration Objective: Determine the viability of the resource i) Heat Source –Energy source ii) Fluid Recharge and pathways –Transport media iii) Reservoir conditions -Permeability, density and heat capacity -fluid chemistry, phase and gases iii) Baseline EIA Make Decision: GO or NO-GO Drill 3 Exploration wells to confirm results (-3,000) -Carry out well testing -Review results Make Decision: GO or NO-GO

  12. Geothermal Development process 2 Stage II: Sizing of the resource • Appraisal Drilling of 6 wells ( depth 2,000 m to 3,000m) • Objective: Determine the size of the resource -(minimum) extent of resource confirmed • -more accurate hydrological model • -Volume, geometry, boundary conditions of resource • -Pressure, Temperature and Overall fluid Chemistry • Feasibility study to determine viability of the project & • Overall Economics: Plant size, type, funding and Tariffs • Complete Environmental Impact assessment • Including public disclosure. • Environment Friendly Power Plant design • Make Decision: GO or NO-GO

  13. Geothermal Development process 3Stage III: Production drilling and Plant Construction Drilling of 16 wells ( depth 2,000 m to 3,000m) Construction of steam gathering system and power plant Put in Place Field and Environmental Management Procedures -Make–up wells (Size, timing and location) -Reservoir monitoring (Pressure, temperature and fluid chemistry) -Re-injection. (Maintain reservoir pressure and water mass) -Rehabilitation. (Return the area close to what it was originally) Use collected data to carry out the following -Optimization of the first plant for efficiency and productivity -Remedial action if needed in response to reservoir effects -Decision whether to increase capacity to second stage

  14. Principles of Operation: Power Generation

  15. Schematic Diagram of Geothermal system Cooling Towers Generator Separators Production Well Water and Steam Injection Well Water

  16. Type of Plants 1:Condensing Dry Steam Power Plant Turbine Generator Steam Electricity Condensed Steam (Water) Steam

  17. Turbine Generator Electricity Steam entry Coiled wire cylinder Turbine blades Magnetic field Steam outlet to condenser

  18. Types of Plant 2:Condensing Flash Steam Power Plant Turbine Generator Steam Flash Tank Electricity Condensed Steam (Water) Hot Water Separated Water

  19. Condensing Flash Steam Plant (Olkaria I & II)

  20. SEPARATOR PRODUCTION WELL CONTROL VALVE (GOVERNOR) G BACK PRESSURE STEAM TURBINE REINJECTION WELL ATMOSPHERIC DISCHARGE Type of Plant 3:Non Condensing Flash Steam Plant

  21. Types of Plant 4:Binary Cycle Power Plant Binary Vapor Turbine Generator Electricity Binary Liquid Heat Exchanger Hot Water Cooled Water

  22. Binary Cycle Power Plant: Heat Exchanger Binary liquid in from condenser Binary vapor out to turbine Hot geothermal water in from production well Geothermal water out to injection well

  23. PRODUCTION BINARY TURBINE COOLING WATER / AIR INJECTION Binary Cycle Power Plant: Aluto Langano –Ethiopia (8MW) & Olkaria III –Kenya (13MW) Steam and water Isopentane HEAT EXCHANGER

  24. Mini-Geothermal Binary Cycle Power Plants: Kapisya – Zambia & Oserian Kenya Kapisya –Zumbu National park, Zambia (160kW) Oserian Dev Company Kenya (2 MW) • Binary plant owned by Zesco • Shallow drilled wells of 150-200m • Built in 1987 and not commissioned • Planed to use water at 90oC • Plant being upgraded by KenGen. • Binary plant owned by Oserian Flower Farm • Commissioned July 2004 • Using steam and re-injecting water • Steam leased from KenGen from 1 well. • Using only one well KenGen is putting up a 2.5 MW Mini-Geothermal binary plant at Eburru Use both steam and water from 1 well. Condense steam to water for community

  25. Lake Baringo Borehole blowout

  26. Principles of Operation: Direct Uses

  27. Heating Heat Exchanger Hot water out to buildings Cold clean water in to be heated Hot geothermal water in from production well Geothermal water out to injection well

  28. Heat Pump in Winter Heat is collected from underground & transferred to the building

  29. District Heating Heat Exchanger Plant Production Wells Injection Well

  30. Geothermal Energy Utilization:Direct Use –Oserian Green houses (Kenya) i) Cut Roses Green house Heating ~100 hectares, ii) Refrigeration of cut flowers storage and processing stores, iii) Injection of CO2 to aid in photosynthesis, iv) Fumigation of soils and sterilization Sterilization of liquid recycled plant fertilizers

  31. Geothermal Energy Utilization:Direct Use II Fish Farming Hot bath/spa Swimming Pool Crocodile Farming

  32. Geothermal Use: Status and Potential in Africa

  33. Geothermal Resources in Africa Potential in the great African Rift > 7,000 MW. Kenya’s geothermal potential is in excess of 3,000 MW Currently only Kenya (130 MW), Ethiopia (8 MW) and Zambia (0.2 MW) have power stations. There are plans to install another 1,000 MW in Eastern Africa over the next 10 years Geothermal energy in North African countries is mainly for greenhouse heating and irrigation

  34. Kenya’s Geothermal Potential • Kenya’s geothermal power potential is estimated at over 3,000 MW. • Most of Kenya's Geothermal potential areas (>20 fields) occur within the Kenya Rift. • Current installed geothermal power: KenGen 115 MW and IPP’s 15 MW. • From above values, only a small fraction of the estimated resource has been harnessed.

  35. Kenya‘s Planned Capacity Expansion Kenya’s Geothermal Potential Geothermal can meet all Kenya’s capacity expansion requirements for the next 15 years

  36. Why slow exploitation of Geothermal ?Barriers to geothermal development • Large up-front investment in exploration, appraisal and production drilling • Funding Constraints: Long financial closure • Technological Constraints: Manpower (development and retention) & Equipment • Environmental & Social issue: Pollution, Land • Commercial & Legislative FrameworkRisks: Country, Market, Corruption, Level Playing Field etc

  37. Overcoming Barriers: Financing Geothermal Projects Kenya’s Experience

  38. Development requirements It is all about MONEY!! • Projects are only worth developing if they create adequate net through life benefit for the developer, whether government or private • This requires a guaranteed revenue stream and manageable risks in resource supply

  39. Financing Geothermal Development-1 • Resource Exploration: Geo-scientific surface studies and exploratory drilling. • In Kenya it’s usually the responsibility of the government • Resource Assessment: Drilling of appraisal wells and well testing • Both the Government & to a lesser extent private sector • Power Plant Development: Drilling of production wells, steam pipelines and Power Plant construction • Shouldered by the Government and Private sector

  40. Current/Future Policy on Funding Options: Resource Exploration and Assessment • Research and Development fund set aside by GoK • Retention of the differential in interest on on-lent funds from GoK • Contracts, consultancies and steam sales • Grants from research programs through individual staff’s proposal writing efforts. • Carbon Credit mechanism. • Risk Guarantee Fund (GEF?) • Utilization of the fuel levy fund.

  41. Future Funding Options: Power Plant Construction stage - 1 • Offering competitive bidding to private and public institutions – local & international. • Strategic alliances e.g. KenGen does all the field development work and sells steam to IPPs. • Carbon credit earned from displacing fossil fuels • Early Generating units to provide cash stream • Demonstrated capacity to generate a portion of the funds required for the investment; typically 25% Government offloading shares to the public

  42. Overcoming Barriers: Human Capacity Development Kenya’s Experience

  43. Geothermal Training in Africa • Geothermal technology -specialized field. • Development of a Geothermist takes many years; • On-job and focused need based training • In the world, training facilities have been offered at: • Inst. for Geothermal Res., Pisa, Italy • Kyushu, Japan • Diploma Course, Auckland University. • UNU-GTP Iceland • Short Course Training in Kenya, KenGen/UNU

  44. Trained v Installed MW

  45. Country No. Trained Retired Available Algeria 3 3 0 Burundi 1 1 0 Djibouti 1 1 0 Egypt 3 0 3 Eritrea 3 1 0 Ethiopia 22 10 11(8 MW) Kenya 41 5 36(130 MW) Tanzania 1 1 0 Tunisia 6 0 6 (Low Temp) Uganda 6 2 3 Totals 86 24 59 UNU Fellows from Africa by 2006

  46. Kenyans Trained at UNU-GTP • 41 people trained • 7 Geophysics • 5 Reservoir Engineering • 6 Geochemistry • 5 Geology • 3 Geothermal utilization • 4 Drilling • 5 Environment • 3 Power Plant • 36 Still active in geothermal • 4 teaching at Universities • 2 Out of the Country • 3 Not active

  47. KenGen’s Geothermal Training Programme (Since 1982) Progressive Graduate Technical staff training 1 year geothermal course -New Zealand (Theory) After 2 years on job, -6 months practical training course–Iceland. 3 months specialized courses at Kyushu -Japan and Pisa -Italy Long specialized courses in USA and Japan (PhD) All contracts/consultancies have a training component Encourages advanced training in Geothermal Technology Staff retention through Keeping them busy when back Out of 26 graduate technical staff on the project, there are 4 PhD and 15 Msc holders

  48. KenGen’s Geothermal Training Programme (Since 1982) KenGen training policy -1 course per staff per year. KenGen Geothermal Training School established 1988 Catering for KenGens internal training needs (esp. technicians) Recently affiliated to United Nations University (Iceland) where joint short courses are offered to ARGeo members Training centre -linked to other International Centres in USA and support by the Global Environment facility of GEF. The East African Rift Countries Tanzania, Djibouti, Kenya, Eritrea, Uganda and Ethiopia formed ARGeo; a regional network of geothermal agents Pool resources, including manpower & Equipment Create partnering required so that trained Africans can train others through the training centre in Kenya

  49. KenGen- UNU Geothermal Training Centre • First course held in November 2005 • Potential contribution of geothermal to national energy needs • Geothermal project management • Focused on decision makers (PS’s, CEO’s etc) • Second course to be held November 2006 • Geothermal resource exploration and appraisal • Participants from: Rwanda, Zambia, Burundi, Tanzania, Djibouti, Kenya, Eritrea, Uganda and Ethiopia • Facilitators: • KenGen, UNU-GTP, ArGeo and GEF

  50. Overcoming Barriers: Lab and equipment Pool Development Kenya’s Experience

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