Geothermal energy has a lot more in common with the shale boom than you might think. Both deploy sophisticated technologies to capture energy from sources deep underground—in shale’s case, that means oil and gas trapped in rock, while for geothermal that entails capturing energy from water and steam heated deep underground. For both energy sources, hydraulic fracturing, the process of shooting a slurry of water, sand, and chemicals into wells at high pressure to break up underlying rock, is providing more access to viable plays than previously thought. Geothermal drillers are taking advantage of fracking, in a process called enhanced geothermal systems (EGS), to access larger underground deposits of water. In so doing, they’re dramatically raising geothermal’s potential to become a major energy player, while also opening the relatively green source up to environmentalist controversy. The Economist reports:
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. […]Geothermal is a steady source of energy (unlike windpower), has very high capacity-utilisation rates, zero fuel costs and near-zero greenhouse-gas emissions…[but] [a]ll 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.
Environmentalists have so far attacked fracking on two grounds: First, that it carries with it a risk of groundwater contamination, and second, that it is opening up new reserves of fossil fuels (though much of America’s fracked gas is displacing much more environmentally damaging coal). Geothermal fracking destroys that second objection, because this particular energy source is very nearly zero-carbon. The first complaint remains, and should EGS techniques take off, one can reasonably expect greens to take up arms against the development of what has been previously seen as an environmentally-friendly energy source.Technology is once again reshaping the energy landscape, and opening up energy reserves that were previously thought un-tappable. The Malthusians and Chicken Littles of the world would have you believe that humanity stands on the precipice of annihilation, as it exhausts the reserves of energy needed to sustain it, but they overlook our remarkable ability to innovate. With the pace of technological change accelerating, more breakthroughs like EGS are sure to follow.