Geothermal electricity is a clean, around-the-clock source of power, but has been limited to those few sites where the earth’s heat has created sources of hot water under the ground. Enhanced Geothermal Systems or EGS generate geothermal electricity without the need for natural hot springs or similar hydrothermal resources.
AltaRock, a Seattle-based geothermal energy company, is making good progress in its efforts to demonstrate the feasibility of EGS technology at a demonstration project underway on the flanks of the Newberry Volcano, about 30 miles south of Bend, Oregon.
The fact is that there are enormous amounts of geothermal energy well within the reach of conventional drilling techniques, but it is in dry, impermeable rock. EGS seeks to enhance or create geothermal resources in hot dry rock through “hydraulic stimulation”.
The process is similar to hydraulic fracking in that liquid is pumped into rock from a well. But it is different from fracking in that the liquid in this case is just cold water. There is no need for the so-called chemical proppants of fracking that are used to keep fractures open. Instead, the water is pumped in, heated up, and pumped back out. The hot water runs turbines, cools off, and the cycle is repeated.
The region near the Newberry site alone is estimated to have up to 5 GW of potential geothermal resource capacity, the equivalent of several large nuclear power plants. AltaRock plans to have its demonstration plant in operation later in the year. The potential for EGS is enormous since it is a base load source of power, that is, it is on all the time.
**********
.
Web Links
The Dream Becomes Real: Touring the Newberry Enhanced Geothermal Site
Photo, posted June 20, 2014, courtesy of Bureau of Land Management (Oregon/Washington) via Flickr.
.
Earth Wise is a production of WAMC Northeast Public Radio.