Pouring Water Into a Volcano To Generate Power 321
Hugh Pickens writes "Until recently, geothermal power systems have exploited only resources where naturally occurring heat, water, and rock permeability are sufficient to allow energy extraction. Now, geothermal energy developers plan use a new technology called Enhanced Geothermal Systems (EGS) to pump 24 million gallons of water into the side of the dormant Newberrry Volcano, located about 20 miles south of Bend, Oregon, in an effort to use the earth's heat to generate power. 'We know the heat is there,' says Susan Petty, president of AltaRock Energy, Inc. of Seattle. 'The big issue is can we circulate enough water through the system to make it economic.' Since natural cracks and pores do not allow economic flow rates, the permeability of the volcanic rock can be enhanced with EGS by pumping high-pressure cold water down an injection well into the rock, creating tiny fractures in the rock, a process known as hydroshearing. Then cold water is pumped down production wells into the reservoir, and the steam is drawn out. Natural geothermal resources only account for about 0.3 percent of U.S. electricity production, but a 2007 Massachusetts Institute of Technology report projected EGS could bump that to 10 percent within 50 years, at prices competitive with fossil-fuels. 'The important question we need to answer now,' says USGS geophysicist Colin Williams, 'is how geothermal fits into the renewable energy picture, and how EGS fits. How much it is going to cost, and how much is available.'"
