Wednesday, May 23, 2018
Publication Date: 07/1/2007
Archive >  July 2007 Issue >  Tech-Op-Ed > 

Is Geothermal the Way to Go?
Walter Salm, Editor
One day, my wife and I walked through a model home that was heated and cooled by geothermal energy. This wasn't in Iceland, where close-to-the-surface geothermal energy rules, nor was it anywhere on the Pacific Ring of Fire. It was in New Jersey, and it utilized the simple temperature differences that exist deep beneath our feet. It was about 10 years ago, and the model home was being shown off by the local power utility to demonstrate that the technology is available here and now. At the time, I believe the geothermal wells and hardware cost about $150,000 over and above the cost of the house. It seemed a bit pricey then; now I'm not so sure. Geothermal energy is one renewable energy resource that is grossly underutilized in the U.S. In places like Iceland, where the geothermal wells don't have to be very deep, it becomes the principal source of energy for both consumers and commercial users. Now it's beginning to catch on in the U.S. After all, the energy is there and available, and isn't it much more practical to have it powering our homes and businesses instead of popping its cork as a volcano and ruining and killing on a massive scale?

Calling geothermal energy "renewable" is a bit of a misnomer, since when you use the energy, it's gone; it does not get replaced. But like sunlight, the power plant seems to have a relatively inexhaustible supply of energy, and the earth's hot, molten core is going to cool down at its own rate, whether we tap into it or not. Smack on the edge of the Ring of Fire, California has numerous sites that have steam and/or hot water geysers, with high levels of geothermal energy available close to the surface. One of these areas is in Lake County, about 120 miles north of Silicon Valley, and not all that far from Santa Rosa. Energy company Calpine, recently out of bankruptcy, is going ahead to capitalize on this ready-to-tap energy source with new investment and a new power plant. It already has a geothermal plant in an area called "The Geysers" near Clear Lake, and plans to spend over $200 million over the next five years drilling new geothermal wells.

It takes two such wells to power a generator. The first well carries surface water that is pumped down into fissures in a hot rock layer. The water spreads through these fissures and is heated to boiling. The superheated water goes back to the surface through another well, where it turns turbines to generate electricity. Then the cooled down water is pumped back down into the hot rocks again.

This is not "dirty" energy such as produced by a coal-fired power plant, nor does it burn up precious petroleum products, like oil and gas fired power plants. This is energy that the earth has stored in great abundance — so much so that every so often, a few volcanos erupt and spew vast amounts of wasted energy over the countryside. Calpine already has 19 geothermal installations in the area; it's now going to vastly expand its presence. Not only does it make good sense from an energy standpoint, California has mandated that all energy companies must provide 20 percent of all their output from renewable sources by 2010. Right now, geothermal accounts for about 5 percent of the state's power needs.

As a renewable source, geothermal is close to ideal. It is constant, not depending on the wind or the sun as with windmills and solar cells. At best, these latter two types of renewable energy simply allow the power grid to shut down several fossil-fuel generators for a period of time. Then when the wind stops and/or night falls, the oil/gas/coal-fired generators have to start up again.

And at some point, when geothermal takes over, it will be fully connected to an important infrastructure — the one needed to use electricity to separate hydrogen from oxygen in our water — providing much needed fuel for the next generation of motor vehicles. Because, yes, I believe in hydrogen power and especially fuel cells. Not tomorrow, but certainly within the next decade. That's when smog-besieged states like California will really be able to clean up their act.  

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