BEND, Ore. (AP) — Engineers have begun pouring cold water on hot rocks thousands of feet below the surface of a dormant volcano in Central Oregon, where two companies hope to show they can generate enough geothermal electricity to power 50,000 homes.
The work began Wednesday, the Bend Bulletin reported (http://bit.ly/VaABhN ). It will continue over the next month at Newberry Volcano, 20 miles south of Bend.
The idea is to create reservoirs of boiling water, as much as 20 million gallons worth, by cracking open fissures in the deep rock.
Drawn to the surface, the boiling water would create steam to spin electricity-generating turbines.
The heat in the earth’s crust has been used to generate power for more than a century. To tap that heat — and grow geothermal energy from a tiny niche into an important source of green energy — engineers are working on a new technology called Enhanced Geothermal Systems.
Most of the locations where hot rocks and water come together naturally to make steam that can turn a turbine have been exploited.
Davenport Newberry and AltaRock Energy of Seattle hope to open a new frontier, where new technologies can create reservoirs of tiny cracks in hot rocks, where cold water can be pumped in to create steam.
Until now, those enhanced reservoirs have not been big enough to power commercial power plants. They have also been dogged by fears of earthquakes.
The project has gotten $21.5 million in federal stimulus funds. Private investors, including Google Inc., have put in a like amount.
The developers hope to generate as much as 50 megawatts of power, but they say an operating power plant is six years away at least.
The water for the cracking process is drawn from a well 600 feet beneath the test site at around 48 degrees. That’s cool enough to contract the 600-degree rocks 10,000 feet below, opening small fissures where the water can boil.
“The colder this water is that we can get in the ground, the better this works,” said Doug Perry of Davenport Newberry.
The process will create small earthquakes. A network of 15 seismic sensors encircles the test site, allowing the depth and location of the small quakes generated during stimulation to be pinpointed.
Project officials say any earthquakes will be too small to be felt, even by the crew at the test site.
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Information from: The Bulletin, http://www.bendbulletin.com
