State is Geothermal Hot Spot
Charleston Gazette
8 October 2010
By Rick Steelhammer
CHARLESTON, W.Va. -- The largest geothermal hot spot in the eastern
United States can be found deep beneath the mountains of eastern West
Virginia, according to research produced by Southern Methodist
University's Geothermal Laboratory.
SMU researchers estimate that the 7,200-square-mile area, most of it
underlying Tucker, Pocahontas, Greenbrier and Randolph counties, is
capable of producing more electricity from geothermal sources than is
now being produced in the state by coal-fired generators.
"The temperatures are high enough to make this the most attractive area
for geothermal energy development in the eastern one-third of the
country," according to an abstract of the research.
SMU's discovery comes from a follow-up survey of a 2004 effort by the
Texas institution to map North America's geothermal resources. During
the earlier mapping effort, only four West Virginia data points were
used. The new research incorporates temperature data recorded by state
oil, gas and water well drillers to add 1,455 additional thermal data
points.
"They used bottom hole temperatures, which oil and gas companies
typically measure when they reach the bottoms of the wells they
are drilling," said State Geologist Michael Hohn, who also serves as
director of the West Virginia Geological and Economic Survey.
Hohn said he was surprised by the SMU discovery, given the absence of
volcanic or other significant tectonic activity in the state.
"When you think of geothermal energy, you think of a place like
Iceland," he said. "There was no strong evidence of this anomaly being
here. We're not exactly sitting on top of Old Faithful here, but what
we've been learning is rather exciting."
According to the SMU study, temperatures of 300 degrees -- hot enough
for commercial geothermal power production -- are found starting at
depths of 4.5 kilometers, or about 15,000 feet in West Virginia's
geothermal zone.
"That's at or beyond the limits of the deeper wells that are now being
drilled," Hohn said. To tap into the source, engineers will have to
develop new techniques to deal with pressures and temperatures
encountered at such depths, he said.
West Virginia's geothermal resources could be tapped by using an
enhanced geothermal system, in which fluid is pumped into the hot rock
area through a pipe looped from one well bore to another.
"Basically, you would use the heat exchange process to heat a liquid,
probably one with a lower boiling point than water, and use it to power
a turbine," Hohn said.
"Geothermal is an extremely reliable form of energy, and it generates
power 24/7, which makes it a baseload source like coal or nuclear,"
said David Blackwell, professor of geophysics at SMU and director of
the university's Geothermal Laboratory.
Assuming only a 2 percent thermal recovery rate, West Virginia has the
potential to produce nearly 19,000 megawatts of electricity from
geothermal sources, according to the SMU researchers. The state
currently produces about 16,300 megawatts from all sources, with coal
accounting for most of the power.
"The proximity of West Virginia's large geothermal resource to East
Coast population centers has the potential to enhance U.S. energy
security, reduce carbon dioxide emissions, and develop high-paying
clean energy jobs in West Virginia," Blackwell said.
The SMU study was conducted with funding from Google.org, the
philanthropic arm of the search engine giant.
"The early West Virginia research is very promising," said Blackwell,
"but we still need more information about local geological conditions
to refine estimates of the magnitude, distribution and commercial
significance" of the state's geothermal resources.
"We need to get a closer look at the rock types and strata in the
geothermal area and learn more about their thermal conductivity," Hohn
said. "We need a more precise definition of the potential that's out
there. ... It's exciting, as geologists, to be able to research this.
It's something you hope to be able to do over the course of your
career."
More information on the SMU study is available at the West Virginia
Geological and Economic Survey's Website at http://www.wvgs.wvnet.edu
Reach Rick Steelhammer at rsteelham...@wvgazette.com or 304-348-5169.