Geothermal Projects and Earthquakes

Very interesting article by James Glanz in the NY Times about new geothermal initiatives and their known relation to earthquakes.

There are generally two kinds of geothermal energy to be tapped. The first, which many are familiar with, is from close-to-the-surface water– heated by hot rising gases, deeper magma or hot rocks. The second is much deeper in the earth, as much as 2 miles or more. To use this energy deep holes are drilled and water is forced down into the super hot rocks, generating steam which then is used at the surface.

The problem is, in both cases but more significantly in the deep drilling, earthquakes. It’s not the drilling itself which causes them but pumping water into the rock. As the water expands it pushes out on the rock along all the tiny fractures inherent in the material, eventually setting off small, and some say, large, earthquakes.

The Times has a marvelous graphic of this which will explain it in about a minute. Click the Start button, here.

The reason this method is attracting interest is clear:

Geothermal’s potential as a clean energy source has raised huge hopes, and its advocates believe it could put a significant dent in American dependence on fossil fuels — potentially supplying roughly 15 percent of the nation’s electricity by 2030, according to one estimate by Google. The earth’s heat is always there waiting to be tapped, unlike wind and solar power, which are intermittent and thus more fickle. According to a 2007 geothermal report financed by the Energy Department, advanced geothermal power could in theory produce as much as 60,000 times the nation’s annual energy usage. President Obama, in a news conference Tuesday, cited geothermal power as part of the “clean energy transformation” that a climate bill now before Congress could bring about.

A similar deep dig in Basel, Switzerland in 2006, set off such an unexpected quake, and all the fears that go with it, the project was shut down.

Triggered quakes are also frequently accompanied by an “air shock,” a loud tearing or roaring noise.

The noise “made me feel it was some sort of supersonic aircraft going overhead,” said Heinrich Schwendener, who, as president of Geopower Basel, the consortium that includes Geothermal Explorers and the utility companies, was standing next to the borehole.

“It took me maybe half a minute to realize, hey, this is not a supersonic plane, this is my well,” Mr. Schwendener said.

By that time, much of the city was in an uproar. In the newsroom of the city’s main paper, Basler Zeitung, reporters dived under tables and desks, some refusing to move until a veteran editor barked at them to go get the story, said Philipp Loser, 28, a reporter there.

Now, AltaRock, with offices in Sausalito, California, is well into drilling near Anderson Springs not far from The Geysers in Northern California, already getting its share of earth quakes from earlier geothermal work. Residents are uneasy, despite the work offered and promise of “clean” energy.

These days, Anderson Springs is a mixed community of working class and retired residents, affluent professionals and a smattering of artists. Everyone has a story about earthquakes. There are cats that suddenly leap in terror, guests who have to be warned about tremors, thousands of dollars of repairs to walls and cabinets that just do not want to stay together.

Residents have been fighting for years with California power companies over the earthquakes, occasionally winning modest financial compensation. But the obscure nature of earthquakes always gives the companies an out, says Douglas Bartlett, who works in marketing at Bay Area Rapid Transit in San Francisco, and with his wife, Susan, owns a bungalow in town.

“If they were creating tornadoes, they would be shut down immediately,” Mr. Bartlett said. “But because it’s under the ground, where you can’t see it, and somewhat conjectural, they keep doing it.”

Very interesting article throughout. Read on.

Maybe Nevada would be a better place to drill….

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