GEOTHERMAL BASICS

Going Green: It's time for a serious look at geothermal energy
Bill Goss, September 16, 2009 (The Newburyport Daily News)

"…What is geothermal energy? …[E]nergy obtained from within the Earth, originating in its core and produced by extracting the Earth's internal heat. How far into the ground the energy is obtained varies from quite close to the surface to miles underground…

"…How does geothermal energy work? …[T]he constant temperature of the Earth creates underground sources of heat, hot water and steam…[M]odern technology accesses these underground reservoirs, steam deposits and hot air by drilling, and then using the heat or hot water directly or using it to create power…[It is] an enormous, under-used power source that provides clean, renewable energy in virtually unlimited supply…"

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"How is geothermal energy used? …[T]he three main uses of geothermal energy are…[1] Direct use and district heating systems, which use hot water from springs or reservoirs near the surface…[2] [P]ower plants…built where geothermal reservoirs are located within a mile or two of the surface [to use the 300-to-700 degree temperatures to boil water to drive turbines]…[3] Geothermal heat pumps use stable ground or water temperatures near the Earth's surface to control building temperatures…"

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"…Where is geothermal energy being used? …The world's largest district heating system is in Reykjavik, Iceland…the once-polluted Reykjavik has become one of the cleanest cities in the world… 95 percent of the buildings…are heated by the district heating system…[T]he U.S. generates more geothermal electricity than any other country…[but] it represents less than .5 percent of electricity produced in the country. Only four states have geothermal power plants: California [90% of U.S. geothermal]…Nevada…Hawaii and Utah…[But some kind of geothermal] can be done almost anywhere in the U.S. …[R]eservoirs of steam or hot water are available primarily in the western states, Alaska, and Hawaii…[U]niversally available geothermal resources — hot dry rock and magma, for example — are awaiting further technology development."

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"…What are some of the benefits of geothermal energy? …[It] can be accessed at all times, the availability is constant…It's clean…emissions are low. It's homegrown…[It is] easy on the land…The land area required for geothermal power plants is smaller per megawatt than for almost every other type of power plant…[It doesn’t] require damming of rivers or harvesting of forests… no mine shafts, tunnels, open pits, waste heaps or oil spills…[P]lants can have modular [expandable] designs…"

"Geothermal energy is clean, available and here. It can be used on a small scale in a single-family home and on larger scales to power entire cities. It's time to look into this virtually untapped resource and really step up our game…Anyone interested in installing a geothermal energy system should do some careful planning…Look for a good company that will…do the job right…at the right price."