Download Geothermal Energy

Geothermal Energy
Presented by:
William Murray
March 28, 2007
What is Geothermal Energy?
• Defined: Energy that is generated by
converting hot water or steam from deep
beneath the Earth’s surface into electricity.
• Unique renewable
• Natural Energy Flow
– Heat Mining
– Enthalpy
The Heat Source
• Tiny quantities of radioactive isotopes
liberate heat as they decay
• Core heat transfer through convection
• Accessible in locations where heats
interior is brought within reach
– Lithospheric Plates
• Significant heat flow
• Volcanic activity
The Heat Source Cont’d
• High enthalpy systems are divided into
two categories
– Vapor Dominated
• Best and most productive
• Free of liquids
– Liquid Dominated
• Relies on water at boiling point
• Often results in steam “flash”
• Two-phase zone
Geothermal Potential
• Nature of the resource
– Fluid Temperature
– Salinity
– Fluid Pressure
– Gas Content
• Economies of Scale
• Maximum efficiency
Four Main Types
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•
•
•
Dry steam power plant
Single flash steam power plant
Binary cycle power plant
Double flash power plant
Dry Steam Power Plant
Single/Double Flash Steam
Binary Cycle Power Plant
Ground Source Heat Pump
Global Capacity
• Worldwide use of geothermal 9.3GW
– 28 GW used directly for heating
– 100GWt through ground-source heat pumps
• Potential for 65-138GW
• MIT claims 100GWe by 2050
• 0.3% of US energy consumption
Environmental Impact
• Gaseous emissions
– Less than 1/10th of coal-fired carbon
emissions
– Dissolved gasses
• Land use
• Noise
• Potential ground subsidence
Geothermal Usage
• Iceland generates 26.5% of energy from geothermal
– .1% Fossil fuels
– 73% Hydro
• In the US
– Alaska (1 Plant)
– California (4.8% of electrical energy, 2.4GW installed
capacity)
– Hawaii (30MW on largest island, 20% of electrical energy)
– Nevada(15 plants, 254MW)
– Utah (reconstructed developing plants)
Applications in Belize
• Belize is the only country in Central
America that does not have the
potential for geothermal energy
according to the US Department of
Energy
QUESTIONS?!!