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!