Enhanced Geothermal System

An enhanced geothermal system, or EGS, generates geothermal electricity in locations that lack the naturally permeable, water bearing hot rock a conventional geothermal plant needs, by pumping high pressure water into wells drilled into hot but tight rock to open and widen existing fractures, then circulating water through the resulting fracture network to carry heat back to the surface, where it drives a steam turbine or a binary power plant. The Fenton Hill project in New Mexico, begun in 1973, was the first major attempt at the technology, followed by several European projects from 1977 onward; a comprehensive 2006 assessment by MIT found the United States held more than 13,000 zettajoules of potential EGS resources, at electricity costs that could fall as low as 3.9 cents per kilowatt hour. The world largest EGS project to date, a 25 megawatt demonstration plant in the Cooper Basin of Australia, has been assessed as capable of supporting 5,000 to 10,000 megawatts of eventual capacity. In 2022 the United States Department of Energy launched its Enhanced Geothermal Shot initiative, aiming to cut the technology cost by 90 percent by 2035, betting on EGS to deliver steady, baseload power essentially anywhere hot rock lies deep enough underground.