|MadSci Network: Environment & Ecology|
Geothermal energy is probably one of the safest and most reliable sources of energy, outside solar energy. It is reliable (the source of heat, the Earth itself, is relatively constant), and hazard, in terms of unwanted waste products or catastrophic accidents, is nonexistent. The primary problem is that only a few places on Earth can provide accessible geothermal energy at a reasonable cost. Iceland, which sits on a plate boundary, makes extensive use of geothermal energy to heat homes and offices. In the central US, a geothermal project would be prohibitively expensive, since it would involve drilling a very deep well, and pumping water down to be heated. This would involve the use of some kind of conventional power, and the net effect would be few (or no) dollar savings in producing heat. Geothermal energy, therefore, is safe and clean, but practical only in locations where the Earth's internal energy emerges at or close to the Earth's surface with regularity.
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