Wednesday, June 24, 2009

"Deep in Bedrock, Clean Energy and Quake Fears"

From the New York Times:

BASEL, Switzerland — Markus O. Häring, a former oilman, was a hero in this city of medieval cathedrals and intense environmental passion three years ago, all because he had drilled a hole three miles deep near the corner of Neuhaus Street and Shafer Lane.

He was prospecting for a vast source of clean, renewable energy that seemed straight out of a Jules Verne novel: the heat simmering within the earth’s bedrock.

All seemed to be going well — until Dec. 8, 2006, when the project set off an earthquake, shaking and damaging buildings and terrifying many in a city that, as every schoolchild here learns, had been devastated exactly 650 years before by a quake that sent two steeples of the Münster Cathedral tumbling into the Rhine.

Hastily shut down, Mr. Häring’s project was soon forgotten by nearly everyone outside Switzerland. As early as this week, though, an American start-up company, AltaRock Energy, will begin using nearly the same method to drill deep into ground laced with fault lines in an area two hours’ drive north of San Francisco.

Residents of the region, which straddles Lake and Sonoma Counties, have already been protesting swarms of smaller earthquakes set off by a less geologically invasive set of energy projects there. AltaRock officials said that they chose the spot in part because the history of mostly small quakes reassured them that the risks were limited.

Like the effort in Basel, the new project will tap geothermal energy by fracturing hard rock more than two miles deep to extract its heat. AltaRock, founded by Susan Petty, a veteran geothermal researcher, has secured more than $36 million from the Energy Department, several large venture-capital firms, including Kleiner Perkins Caufield & Byers, and Google. AltaRock maintains that it will steer clear of large faults and that it can operate safely.

But in a report on seismic impact that AltaRock was required to file, the company failed to mention that the Basel program was shut down because of the earthquake it caused. AltaRock claimed it was uncertain that the project had caused the quake, even though Swiss government seismologists and officials on the Basel project agreed that it did. Nor did AltaRock mention the thousands of smaller earthquakes induced by the Basel project that continued for months after it shut down.

The California project is the first of dozens that could be operating in the United States in the next several years, driven by a push to cut emissions of heat-trapping gases and the Obama administration’s support for renewable energy.

Some geothermal advocates believe the method used in Basel, and to be tried in California, could be that breakthrough. But because large earthquakes tend to originate at great depths, breaking rock that far down carries more serious risk, seismologists say. Seismologists have long known that human activities can trigger quakes, but they say the science is not developed enough to say for certain what will or will not set off a major temblor.

Even so, there is no shortage of money for testing the idea. Mr. Reicher has overseen a $6.25 million investment by Google in AltaRock, and with more than $200 million in new federal money for geothermal, the Energy Department has already approved financing for related projects in Idaho by the University of Utah; in Nevada by Ormat Technologies; and in California by Calpine, just a few miles from AltaRock’s project....

By the time people were getting off work amid rain squalls in Basel on Dec. 8, 2006, Mr. Häring’s problems had already begun. His incision into the ground was setting off small earthquakes that people were starting to feel around the city.

Mr. Häring knew that by its very nature, the technique created earthquakes because it requires injecting water at great pressure down drilled holes to fracture the deep bedrock. The opening of each fracture is, literally, a tiny earthquake in which subterranean stresses rip apart a weak vein, crack or fault in the rock. The high-pressure water can be thought of loosely as a lubricant that makes it easier for those forces to slide the earth along the weak points, creating a web or network of fractures.

Mr. Häring was rushed to police headquarters in a squad car so he could explain what had happened. By the time word slipped out that the project had set off the earthquake, Mr. Loser said, outrage was sweeping the city. The earthquakes, including three more above magnitude 3, rattled on for about a year — more than 3,500 in all, according to the company’s sensors.

Although no serious injuries were reported, Geothermal Explorers’ insurance company ultimately paid more than $8 million in mostly minor damage claims to the owners of thousands of houses in Switzerland and in neighboring Germany and France....

There was a time when Anderson Springs, about two miles from the project site, had few earthquakes — no more than anywhere else in the hills of Northern California. Over cookies and tea in the cabin his family has owned since 1958, Tom Grant and his sister Cynthia Lora reminisced with their spouses over visiting the town, once famous for its mineral baths, in the 1940s and ’50s. “I never felt an earthquake up here,” Mr. Grant said .

Then came a frenzy of drilling for underground steam just to the west at The Geysers, a roughly 30-square-mile patch of wooded hills threaded with huge, curving tubes and squat power plants. The Geysers is the nation’s largest producer of traditional geothermal energy. Government seismologists confirm that earthquakes were far less frequent in the past and that the geothermal project produces as many as 1,000 small earthquakes a year as the ground expands and contracts like an enormous sponge with the extraction of steam and the injection of water to replace it.

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.”

1 comment:

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