Why geothermal is the new fracking
The industry may dislike the comparison, but EGS is geothermal fracking. Millions of gallons of water and chemicals are injected into mostly vertical wells at relatively high pressure, and the combination of cold-meets-hot, pressure and chemistry shears the deep, hot rock. This creates new “fracture networks” through which water can be pumped, heated and sent back to the surface to generate power. Conventional geothermal wells cost at least $5m to develop, and about half fail. The new technique can reduce the failure rate and extend the size and life of existing geothermal fields. In time, think EGS fans, it will allow geothermal fields to be established wherever there is suitable hot rock.
The U.S. energy department reckons that EGS techniques could be commercially viable as soon as next year, at which point more private investors and perhaps utilities might pile in. It is not alone in its optimism: Germany, France and Britain have state research programmes for EGS.
All this has environmentalists gearing up for another fight. EGS can trigger earthquakes. Most are minuscule but an early project on a seismic fault in Basel, Switzerland was scrapped after several not-so-small quakes. It is also possible that water used for EGS may leak, contaminating surface waters or soil. America has rules to ensure EGS’s safety, and every project is surrounded by seismometers. Whether this will prevent protests or prohibitions is open to hot debate.
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