If we could extract all the geothermal energy that exists underneath the United States to a depth of two miles, it would supply America's power demands (at the current rate of usage) for the next 30,000 years. Getting at all that energy is not feasible-there are technological and economic impediments-but drawing on just 5 percent of the geothermal wealth would generate enough electricity to meet the needs of 260 million Americans. The Department of Energy's National Renewable Energy Laboratory (NREL) asserts that reaching that 5 percent level, which would produce 260,000 megawatts of electric power and reduce our dependence on coal by one-third, is doable by 2050.
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