Benefits of Geothermal Energy By Dr. Silas Simiyu

Transcription

1 Benefits of Geothermal Energy By Dr. Silas Simiyu

2 Introduction Geo means Thermal means

3 Intoduction The Earth Crust Mantle Outer core Inner core

4 Is renewable and sustainable Reservoir managed well (Re-injection)

5 E.A. Rift System East African Rift Potential > 15,000 MWe Exploited 217 MWe (< 2%)

6 Schematic of Geothermal system Generator Cooling Towers Separators Production Well Water and Steam Injection Well Water

7 Condensing Flash Steam Power Plant Flash Tank Steam Turbine Generator Electricity Hot Water Separated Water Condensed Steam (Water)

8 Condensing Dry Steam Power Plant Steam Turbine Generator Electricity Steam Condensed Steam (Water)

9 Binary Cycle Power Plant Binary Vapor Turbine Generator Electricity Binary Liquid Heat Exchanger Hot Water Cooled Water

10 Generates continuous, reliable baseload power Olkaria I power plant: 97% availability since 1981 Low operation costs, Not affected by weather

11 Olkaria II 105 MWe power plant Geothermal power plants have no smoky emissions Only emit water vapor and can earn Carbon credits

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

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

14 Factors that could Affect Geothermal Development High initial upfront Risks & Heavy investment requirement Risk Mitigation funds (KfW, ArGeo & WB) Recent Improvement in resource targeting technology (100% success) Long project Gestation Period Early wellhead Generation Raising capital for faster development

15 Factors that could Affect Geothermal Development Human Capacity Development Available training facilities Iceland, New-Zealand, Japan, Italy, Philippines, Kenya Environmental Concerns 100% re-injection and Efficient gas extraction technology

16 Computer Architecture Centralized Mainframe Computer Decentralized Peer to Peer Personal Computers Network Network Router Mainframe Non-Intelligent Terminals Intelligent Workstations Fileserver

17 Geothermal PowerPlant Architecture Conventional Centralized Geothermal Power Plant. Mainframe Generator Kaldara Decentralized Geothermal Power Plant. Personal Generators Distance < 2 km Borehole On-Surface Steam Pipes Borehole Distance < 2 km 60 MW Power Plant 60 MW Power System KAPS 5 MW Power Unit Connections Max Distance >> 2+2 = 4 km Overhead 132 kv Transmission Line Substation Sub-surface Power Cables Substation Overhead 132 kv Transmission Line Max Distance >> 2+2 = 4 km

18 Production start-up Typical Total Geothermal Power Startup Procedure Conventional Geothermal Power Plant ~ 50 MW Phase 1.Year 2.Year 3.Year 4.Year 5.Year 6.Year 7.Year 8.Year 9.Year 10+.Year Geological Research Drilling Evaluation Construction Operation 6 years earlier startup Start of Production KAPS Units 5 MW Phase 1.Year 2.Year 3.Year 4.Year 5.Year 6.Year 7.Year 8.Year 9.Year 10+.Year Geological Research Drilling Construction Operation Start of Production

19 Production start-up 60 Comparing 10*5=50 MW KAPS and 50 MW Conventional Geothermal 50 Installed MW *5=50 MW KAPS 50 MW Conventional Geothermal Increased production in the KAPS setup is 1500 GWh. With energy price of 100 EURO/MWh it is valued at 150 million EURO Years

20 Layout of 5 MW KAPS-Unit A From Production Boreholes To Reinjection Boreholes 25 m C O N D E N S E R Separator Electricals Working Area Turbines/Generator 4 m 4 m Section A-A B Concrete Slab A 35 m Cooling Towers B Section B-B 4 m

21 Schematic of Geothermal system Generator Cooling Towers Separators Production Well Water and Steam Injection Well Water

22 Direct Use Benefits of Geothermal Energy

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26 Geothermal Energy Utilization: Direct Use Fish Farming Hot bath/spa Crocodile Farming Swimming Pool

27 Benefits cont. Easy on the Environment Geothermal power plants have been built: In the middle of crops In forested recreation areas In fragile deserts In tropical forests Little land

28 Benefits cont. Geothermal energy is Clean and Renewable Geothermal power stations emit less greenhouse gases compared to other sources of energy Saves on dirty fossil fuel that could be used for purposes Contributes to diversity in the Energy mix 10 SO CO Coal Oil Gas Geo 0 Coal Oil Gas Geo

29 Benefits cont. Avoids importing and benefits local economies Geothermal occur in remote and mountainous environments Opens up remote areas, offers employment improves conditions of living for local communities Indigenous, used on site, saves on foreign exchange CDM benefits (carbon credits)

30 Benefits cont. Direct uses: Touristic attraction Spas and swimming pools Heating greenhouse and houses in cool months Drying of agricultural products Fish rearing where no lakes/rivers Processing of dairy products

31 Compared to other Gen. Modes Annual Fixed cost($/kwh) Total variable cost($/kwh) Geothermal Nuclear Coal Total annualized cost($/kwh) (0.0506) With Early WHG Source: LCPDP

32 Conclusions Geothermal energy is a clean, cheap, benign, indigenous source of energy. Remains the most suitable form of Energy for the future in the Region. Reykjavik in 1930 Reykjavik in 990

33 Thank you!