[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2014/04/EW-04-21-14-Volcano-Power.mp3|titles=EW 04-21-14 Volcano Power]
For decades, geothermal wells have been used to power turbines to generate electricity. These wells utilize heat from the earth’s core by tapping into underground sources of hot water. Recently, scientists have made progress drilling directly into volcanoes and using molten rock – or magma – as a much more potent energy source.
In the 1980s, a geothermal well in Iceland inadvertently tapped into a reservoir of superheated water that was released as steam and carried enormous amounts of energy. Such so-called supercritical steam can be 500o Celsius or even higher in temperature. Over the intervening decades, a plan emerged to use nearby magma as a source of heat to create superheated steam. Typical geothermal wells can produce 5-10 megawatts of electricity. Supercritical wells could potentially yield ten times that much.
In 2011, researchers at the Icelandic Deep Drill Project, which is a consortium of energy companies and scientists, drilled a well into a pocket of magma, which ruined their equipment. Recognizing an opportunity, however, they then located a new well just above the magma pocket and were able to generate superheated steam and 35 megawatts of electricity. Unfortunately, the equipment only survived 2 years in its harsh operating environment.
Magma-heated energy systems can only be located near an active volcano and even then they require very precise location. Such wells won’t ever become commonplace. Nevertheless, where such systems are feasible, they have enormous potential as excellent sources of clean and low-cost energy.
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Photo, taken November 25, 2010, courtesy of John Cooke via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.