Thursday, February 21, 2008

Geothermal, the Unsung Power Source


Electricity from geothermal power rarely gets ink in the press the way more glamorous renewables do—including solar, wind, and biomass—but in some places, such as California, it already is making a substantial contribution to power requirements. A recent article in talked about the efforts in The Geysers to harvest energy from underground steam.

The potential for this energy source is signficant:

In all, The Geysers generates 4.7 percent of California's electricity - far more than solar, wind and biomass projects - and its capacity again is growing.

The Geysers is part of a nationwide boom. A recent report from the Geothermal Energy Association in Washington, D.C., showed a 40 percent increase in the number of geothermal projects around the country in just the last year. It said 86 new projects are under way in 12 states with a potential capacity of 3,368 megawatts. In California, one megawatt is enough to power 1,000 homes for a year.

In fact, it's a global phenomenon. "Geothermal is a hot topic around the world," said ThermaSource's Capuano, a big man with a lot of Mississippi still in his voice.

The Union of Concerned Scientists offers a good overview explanation of the geothermal potential in the U.S. here. The summary paragraph reads:

The U.S. Geological Survey estimates the geothermal resource base in the United States to be between 95,000 and 150,000 MW, of which about 22,000 MW have been identified as suitable for electric power generation. Unfortunately, only a fraction of this resource is currently utilized, with an installed capacity of 2,800 MW (worldwide capacity is approximately 8,000 MW). But thanks to declining costs and state and federal support, geothermal development is likely to increase. Over the next decade, new geothermal projects are expected to come online to increase U.S. capacity to between 8,000 and 15,000 MW. As hot dry rock technologies improve and become competitive, even more of the largely untapped geothermal resource could be developed. In addition to electric power generation, which is focused primarily in the western United States, there is a bright future for the direct use of geothermal resources as a heating source for homes and businesses everywhere.