<http://schema.org/about>
"Large reserves of heat reside as stored thermal energy deep within the Earth's crust. Mining this energy could meet a significant portion of the United States' future energy needs, at competitive prices and with minimal environmental impact, according"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/renewable-energy/is-geothermal-energy-the-way-of-the-future.html>