This is an excerpt from EERE Network News, a weekly electronic newsletter.
Drilling Underway for First Commercial Hot Dry Rock Facility
The first commercial endeavor to develop geothermal power from a hot dry rock (HDR) resource is now underway in Australia. With the help of a $5 million federal grant, Geodynamics Limited began drilling its "Habanero 1" well on February 15th. The well will extend about 3 miles under South Australia's Cooper Basin to tap one of the world's hottest geothermal resources. When the well is complete in 10 to 12 weeks, it is expected to reach an underground "hot spot" where rocks achieve temperatures of about 554 degrees Fahrenheit. See the Geodynamics Limited press release.
Unlike today's geothermal power plants, which draw on existing underground reservoirs of water and steam heated by the earth, HDR technology draws energy from underground hot spots where no water exists. The technology involves drilling a well down to the hot rock, injecting high-pressure water to fractionate the rockcreating a reservoir of fissures filled with waterand then drilling a separate well to draw hot water back up from the reservoir. The hot water is used to produce power on the surface, then injected back into the first well. For further information, see the Geodynamics Limited Web site.