to create electricity. But you have to dig:
The extraordinary amount of heat seething below Earth's hard rocky crust could help supply the United States with a significant fraction of the electricity it will need in the future, probably at competitive prices and with minimal environmental impact, scientists now claim.
An 18-member panel led by MIT has prepared the first study in some 30 years to take a new look at the largely ignored area of geothermal energy.
Geothermal plants essentially mine heat by using wells at times a mile or more deep. These wells tap into hot rock and connect them with flowing water, producing large amounts of steam and super-hot water that can drive turbines and run electricity generators at the surface.
....The United States is the world's biggest producer of geothermal energy. Nafi Toksöz, a geophysicist at MIT, noted that the electricity produced annually by geothermal plants now in use in California, Hawaii, Utah and Nevada is comparable to that produced by solar and wind power combined.
However, existing U.S. plants are concentrated mostly at isolated regions in the West. There, hot rocks are closer to the surface, requiring less drilling and thus lowering costs. Even then, drilling must reach depths of 5,000 feet or more in the West, and much deeper in the eastern United States.