This post is by Miriam Horn, a writer at Environmental Defense Fund and co-author of the New York Times bestseller, Earth: The Sequel. It's part of a video series on new energy technologies, Unleash the Future.
While solar, wind and wave energy all originate with the Sun, the heat locked up in the Earth itself offers another huge potential energy resource. Historically, that "geothermal" power could be converted into electricity only in those rare locations where natural fissures allowed water to flow into deep hot rock and come to the surface at temperatures high enough to generate steam. Now an innovator in Alaska has developed the first low-temperature geothermal power plant, which United Technologies is commercializing for worldwide sale.
Take a look at my short video on geothermal power to learn more.
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If you have any questions or comments on geothermal energy, please post them here. I'll do my best to answer.