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West Virginia Is a Geothermal Hot Spot

4 October 2010 5:02 pm
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Source: Southern Methodist University and Google.org

Hot or not? A new map of underground temperatures suggests that West Virginia has great potential for geothermal energy.

Researchers have uncovered the largest geothermal hot spot in the eastern United States. According to a unique collaboration between Google and academic geologists, West Virginia sits atop several hot patches of Earth, some as warm as 200˚C and as shallow as 5 kilometers. If engineers are able to tap the heat, the state could become a producer of green energy for the region.

In 2004, researchers at Southern Methodist University (SMU) in Dallas, Texas, and colleagues created the Geothermal Map of North America. The map charted the potential for geothermal energy nationwide. Two years ago Google.org, the philanthropic arm of the search engine giant, hired the SMU scientists to update the map.

The group analyzed temperature data from oil and gas firms that no one had bothered to map. Those data were collected via single thermometer readings on the end of drilling equipment, but the readings were artificially low because of water used to cool and wash the equipment. So the SMU team corrected the readings according to the rock type that was being drilled. Then the researchers estimated the temperatures of adjacent rock layers according to their geologic properties.

The work revealed surprising results for West Virginia, a state that had only four data points in the 2004 map. The Google.org-funded effort added measurements from more than 1450 wells in the state. The warm spots were found at depths of 3 to 8 kilometers over an 18,700-square-kilometer area. By comparison, geothermal hot spots in Nevada reach 200˚C at 2 kilometers below the surface, and steam produced from them runs turbines to create electricity. Iceland, meanwhile, has 200˚C temperatures just below the surface and uses warm water to heat buildings and showers throughout Reykjavik and elsewhere.

The find was a surprise to the scientists themselves as well as to local experts. "Nobody expected West Virginia to show up as a hot spot," says SMU's Maria Richards, a geothermal expert and geographer. "Just last year, I thought West Virginia, geothermal energy—I didn't put the two together," adds West Virginia's official state geologist, Michael Hohn, who didn't participate in the study.

The SMU team plans to confirm the discovery by drilling new wells in areas where the oil data was light. But experts are already weighing how the state might exploit the geothermal energy. Electricity is extremely cheap in West Virginia due to its abundant coal, so geothermal energy probably can't compete for business from utilities there. But Hohn says the state's extensive network of power lines makes it a good candidate for exporting electricity produced by geothermal power to nearby states such as Maryland, Virginia, and Pennsylvania.

Chemical engineer Brian Anderson of West Virginia University in Morgantown, who didn't participate in the work, says that even relatively low geothermal temperatures, like those seen in this study, can be useful to engineers. Researchers can tap these spots to produce electricity using antifreeze-like fluids that boil at lower temperatures than water, powering steam turbines. "I do see a lot of potential for this."

The original article misspelled the name of West Virginia's state geologist, Michael Hohn.

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