Hot Promises of Geothermal Energy

| Tue Jan. 23, 2007 1:35 PM PST

A Massachusetts Institute of Technology-led study of geothermal energy within the US finds that mining the huge amounts of thermal energy stored in the Earth's rock crust could supply a substantial portion of the nation's electricity needs currently being generated by conventional fossil fuel, hydroelectric, and nuclear plants—at competitive prices and with minimal environmental impact. Go deep enough, and there's heat everywhere.

The study shows that drilling several wells to reach hot rock and connecting them to a fractured rock region that has been stimulated to let water flow through it creates a heat-exchanger that can produce large amounts of hot water or steam to run electric generators at the surface. Unlike conventional fossil-fuel power plants that burn coal, natural gas or oil, no fuel would be required. And unlike wind and solar systems, a geothermal plant works night and day, offering a non-interruptible source of electric power.

… "This environmental advantage is due to low emissions and the small overall footprint of the entire geothermal system, which results because energy capture and extraction is contained entirely underground, and the surface equipment needed for conversion to electricity is relatively compact," [Jefferson W.] Tester [the H. P. Meissner Professor of Chemical Engineering at MIT] said.

… Panel member Brian Anderson, an assistant professor at West Virginia University, noted that the drilling and reservoir technologies used to mine heat have many similarities to those used for extracting oil and gas. As a result, the geothermal industry today is well connected technically to two industry giants in the energy arena, oil and gas producers and electric power generators. With increasing demand for technology advances to produce oil and gas more effectively and to generate electricity with minimal carbon and other emissions, an opportunity exists to accelerate the development of EGS by increased investments by these two industries.

The study notes that government-funded research into geothermal was highly active in the 1970s and early 1980s, but that as oil prices declined, funding and geothermal research waned. Time to heat that up again.

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