benefits of geothermal energy by dr. silas simiyu · geo means thermal means. intoduction the earth...
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Benefits of Geothermal EnergyBenefits of Geothermal Energy
ByBy
Dr. Silas SimiyuDr. Silas Simiyu
IntroductionIntroduction
Geo means
Thermal means
IntoductionIntoductionThe Earth
Crust
Mantle
Outer core
Inner core
•Is renewable and sustainable•Reservoir managed well (Re-injection)
E.A. Rift System
East African Rift Potential> 15,000 MWeExploited 217 MWe (< 2%)
Production WellWater and Steam
Injection WellWater
Schematic of Geothermal system
Separators
Cooling Towers
Generator
Condensing Flash Steam Power Plant
Separated Water
Steam
CondensedSteam (Water)Hot
Water
Turbine GeneratorFlashTank Electricity
Condensing Dry Steam Power Plant
Turbine Generator
SteamCondensedSteam (Water)
Electricity
Steam
Binary Cycle Power Plant
Binary Vapor Turbine Generator
Electricity
Binary Liquid
Heat Exchanger
CooledWater
HotWater
• Generates continuous, reliable “baseload” power
• Olkaria I power plant: 97% availability since 1981
• Low operation costs, Not affected by weather
Olkaria II 105 MWe power plantOlkaria II 105 MWe power plant�Geothermal power plants have no smoky emissions�Only emit water vapor and can earn Carbon credits
Heat Exchanger
Hot water outto buildings
Hot geothermalwater in fromproduction wellGeothermal water
out to injection well
Cold clean water into be heated
Heat Pump in Winter
Heat is collected fromunderground & transferred
to the building
�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
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
Factors that could Affect Geothermal Development
Network
Network Router
Computer ArchitectureCentralized
Mainframe ComputerDecentralized Peer to Peer
Personal Computers
IntelligentWorkstations
File-server
Non-IntelligentTerminals
Mainframe
On-Surface Steam Pipes
Distance < 2 km
Distance <
2 kmOverhead 132 kV Transmission Line
Conventional Centralized GeothermalPower Plant. “Mainframe Generator”
Kaldara Decentralized GeothermalPower Plant. “Personal Generators”
Borehole
60 MWPower Plant
Borehole
KAPS 5 MW Power Unit
Sub-surface Power Cables
Max Distance >> 2+2 = 4 km
Max D
istance >>
2+2 =
4 km
Substation
Connections
60 MWPower System
Substation
Overhead 132 kV Transm
ission Line
Geothermal PowerPlant Architecture
Phase 1.Year 3.Year 4.Year 5.Year 6.Year 7.Year 8.Year 9.Year 10+.YearGeological ResearchDrillingEvaluationConstructionOperation
2.Year
Phase 1.Year 3.Year 4.Year 5.Year 6.Year 7.Year 8.Year 9.Year 10+.YearGeological ResearchDrillingConstructionOperation
2.Year
Production start-upTypical Total Geothermal Power Startup Procedure
Conventional Geothermal Power Plant ~ 50 MW
KAPS Units 5 MW
Start of Production
Start ofProduction6 years earlier startup
Production start-upComparing 10*5=50 MW KAPS
and 50 MW Conventional Geothermal
0
10
20
30
40
50
60
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16Years
Inst
alle
d M
W 10*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
From Production BoreholesTo Reinjection Boreholes
CONDENSER
Concrete Slab 35 m
25 m
Layout of 5 MW KAPS-Unit
Electricals
Separator
Turbines/Generator
Section A-A
4 m
Cooling Towers
4 m
4 m
B
Section B-B
A
B
A
Working A
rea
Production WellWater and Steam
Injection WellWater
Schematic of Geothermal system
Separators
Cooling Towers
Generator
Direct Use Benefits of Geothermal Energy
Geothermal Energy Utilization:Direct Use
Fish Farming Hot bath/spa
Crocodile Farming Swimming Pool
Easy on the Environment
�In the middle of crops
�In forested recreation areas
�In fragile deserts
�In tropical forests
�Little land
Geothermal power plants have been built:
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
0
5
10
Coa
l
Oil
Gas
Geo
SO2
0
500
1000
Coa
l
Oil
Gas
Geo
CO2
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)
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
Benefits cont.
Compared to other Gen. ModesCompared to other Gen. ModesGeothermal Nuclear Coal
Annual Fixed
cost($/kwh)0.0826 0.0759 0.0473
Total variable
cost($/kwh)0.00361 0.0117 0.0576
Total annualized
cost($/kwh)0.08621
(0.0506) With Early WHG
0.0876 0.1006
Source: LCPDP
��Geothermal energy is a clean, cheap, Geothermal energy is a clean, cheap, benign, indigenous source of energy.benign, indigenous source of energy.
��Remains the most suitable form of Remains the most suitable form of Energy for the future in the Region.Energy for the future in the Region.
ConclusionsConclusions
Reykjavik in 1930 Reykjavik in 990
Thank you!