Sustainable Energy Systems Engineering Peter Gevorkian Ch 12: Geothermal Energy Brevard Community College ETP1420 Bruce Hesher

Geothermal is a concatenation of the words Geo “earth” and Thermal “heat”. Geothermal is a concatenation of the words Geo “earth” and Thermal “heat”. There are 2 types of geothermal energy: There are 2 types of geothermal energy: Energy from the earth’s molten core: Used to make steam energy. Not viable in Florida. Energy from ground temperature: Used for cooling and heating. Viable in Florida

Geothermal Resources p273 Hot water reservoirs: Natural steam reservoirs: Natural steam reservoirs: Geo-pressured reservoirs: Geothermal Gradients: Geothermal Gradients: Molten Magma: Ground temperature: Ground temperature:

The U.S. Resource

Geothermal Heat Pumps (GHP) Also referred to as GeoExchange, earth-coupled, ground- source, or water-source heat pumps) have been in use since the late 1940s. GHPs use the constant temperature of the earth as the exchange medium instead of the outside air temperature. Also referred to as GeoExchange, earth-coupled, ground- source, or water-source heat pumps) have been in use since the late 1940s. GHPs use the constant temperature of the earth as the exchange medium instead of the outside air temperature. Although your first thought for cooling may be air conditioning, there are many alternatives that provide cooling with less energy use. A combination of proper insulation, energy-efficient windows and doors, daylighting, shading, and ventilation will usually keep homes cool with a low amount of energy use in all but the hottest climates. Although ventilation should be avoided in hot, humid climates, the other approaches can significantly reduce the need to use air conditioning. Although your first thought for cooling may be air conditioning, there are many alternatives that provide cooling with less energy use. A combination of proper insulation, energy-efficient windows and doors, daylighting, shading, and ventilation will usually keep homes cool with a low amount of energy use in all but the hottest climates. Although ventilation should be avoided in hot, humid climates, the other approaches can significantly reduce the need to use air conditioning.

Using the Temperature of the ground Copper or plastic piping run under ground can provide both cooling in summer and heating in winter! Energy is only need to circulate and heat exchange but, not to change the temperature! Copper or plastic piping run under ground can provide both cooling in summer and heating in winter! Energy is only need to circulate and heat exchange but, not to change the temperature!

Detailed Geothermal Map

Geothermal Power Extraction Potential p275 The earth’s crust is thin. The inner heat of the Earth will last for Billions of years.

Types of Geothermal Plants p275 Dry Steam Plants: Use natural steam. Use hot water and steam over 300°F. Must be located where resource is. Binary Plants: Lower temperature systems that use a secondary gas with a lower vapor temp. More location options. Flash Steam Plants: Use dropping pressure to create steam.

Types of Geothermal Heat Pump Systems opic= opic=12650

Potential of Geothermal Power p277 The Pacific Northwest of the U.S. has the potential to generate up to 11,000 MW. The Northwest Power Planning Council has identified 11 sites where it expects there are about 2,000 MW to be developed. This will power about 1.3 million homes! The Pacific Northwest of the U.S. has the potential to generate up to 11,000 MW. The Northwest Power Planning Council has identified 11 sites where it expects there are about 2,000 MW to be developed. This will power about 1.3 million homes!

Cost of Geothermal energy and Economics p278 The estimate of geothermal electric power cost is about 4.5 to 7 cents per KWH. For comparison, FPL charges 11 to 12 cents per KWH. Geothermal has no associated pollution costs. The estimate of geothermal electric power cost is about 4.5 to 7 cents per KWH. For comparison, FPL charges 11 to 12 cents per KWH. Geothermal has no associated pollution costs.

Environmental impact of Geothermal Power p280 Although geothermal is low pollution it must be located where there is a resource to be tapped into. There are heavy metals sometimes found in geothermal heated water, so re-injection wells must be built to account for it. Although geothermal is low pollution it must be located where there is a resource to be tapped into. There are heavy metals sometimes found in geothermal heated water, so re-injection wells must be built to account for it. Plants must be designed not to cool nearby hot springs or intermix with ground water used for agriculture. Plants must be designed not to cool nearby hot springs or intermix with ground water used for agriculture.

Benefits, Uses, and Disadvantages of Geothermal Power p280 Clean, safe energy with little land space. Clean, safe energy with little land space. Sustainable and renewable. Sustainable and renewable. Continuous and reliable power. Continuous and reliable power. Cost competitive. Cost competitive. Conserves fossil fuel. Conserves fossil fuel. Reduces energy imports. Reduces energy imports. Benefits local economies. Benefits local economies. Power plants are modular and scalable. Power plants are modular and scalable.

Advantages Balneology: Hot springs, baths, bathing Agriculture: Greenhouses and soil warming Aquaculture: fish, prawn, and alligator farms. Industrial: product drying and warming Direct Heating: residential and industrial Direct Uses  Environmentally friendly.  Reliable and can produce uninterrupted power.  Flexible; can produce electricity, hot water, etc.  Efficient; vast resource

Ocean Thermal Energy p281 The difference in temperature between the ocean surface and deep ocean is large and can be used as an energy source. Technologies are being developed to use it in both Japan and Hawaii. The difference in temperature between the ocean surface and deep ocean is large and can be used as an energy source. Technologies are being developed to use it in both Japan and Hawaii.