GEOTHERMAL SHAKES THINGS UP

German Geothermal Project Leads to Second Thoughts After the Earth Rumbles
Nicholas Kulish and james Glanz, September 10, 2009 (NY Times)

"[German] government officials…are reviewing the safety of a geothermal energy project that scientists say set off an earthquake in mid-August, shaking buildings and frightening many residents of [the small city of Landau].

"The [$30 million ] geothermal plant, built [in 2007] by Geox, a German energy company, [produces electricity for 6,000 homes by drawing heat from beneath the bedrock]…by drilling [nearly 2 miles] into the earth. Advocates of the method say that it could greatly reduce the world’s dependence on fossil fuels by providing a vast supply of renewable energy."

An earthshaking New Energy concept (continued below). (click to enlarge)

"But in recent months, two similar projects have stirred concerns about their safety and their propensity to cause earthquakes. In the United States, the Energy Department is scrutinizing a project in Northern California run by AltaRock Energy to determine if it is safe…[It] was shut down by the company last month because of crippling technical problems…Another project, in Basel, Switzerland, was shut down after it generated earthquakes in 2006 and 2007 and is awaiting the decision of a panel of experts…The Landau project will be allowed to continue operating while the review panel…[sorts] through the conflicting data presented by the company and government scientists.

"…[Geothermal advocates] worry that projects like the one in Germany…could damage the reputation of geothermal energy, even in highly environmentally conscious areas of the world like California or Western Europe…Like other earthquakes that have been attributed to geothermal plants, the Landau temblor was sudden and brief and was accompanied by a sound that in some cases has been likened to a sonic boom. There were no injuries and there was no known structural damage to buildings in the city. But the 2.7 magnitude quake has stoked fears and set off debate in the state Parliament, which subsidized the construction of the plant, about the method’s safety…The police logged as many as 200 calls after the [August 15] quake…"

An earthshaking New Energy concept (continued). (click to enlarge)

"Citing an academic paper, officials of AltaRock, the company running the California project, claimed that the Landau plant caused no earthquakes…In fact, in May, the state geological survey for Rhineland-Palatinate, the state where Landau is located, concluded that four minor earthquakes, too small to be felt by residents, had been generated by the project…Seismologists at the geological survey said that the larger Aug. 15 quake was also caused by the project. The epicenter was roughly 500 yards from a drill site at the plant and at about the same depth — 1.5 miles — as a steam bed that the plant was extracting heat from…

"…Geox officials conceded that the plant had set off tiny earthquakes and said that they were not certain what set off the Aug. 15 temblor. But consultants for the company dispute the data cited by government scientists to back up their conclusion that the project caused the earthquake: their own data, they said, proves that the quake originated more than two miles from the site of the plant and six miles below the earth’s surface…essentially [ruling] out a connection with the plant…Not everyone in town was troubled by the quake…[but some] residents said they were skeptical about the new technology…"