Photo Source: nytimes.com
One hundred and counting. That’s the number of comments that readers have submitted regarding a New York Times story published Wednesday that says the startup AltaRock Energy plans to begin exploratory drilling for geothermal energy sources in Northern California, using a method similar to one that caused earthquakes in a similar project in Basel, Switzerland. Many comments support the reporter’s findings, while a good number criticize the story as being one-sided or sensational.
This is, of course, not the first time that the merits of geothermal energy – whereby heat is mined from the earth, sometimes by pumping water into bedrock and capturing the resulting steam – have been contested. Some claim that on large scales, geothermal energy will contribute to climate change by emitting more heat into the atmosphere, and beside that, some say that it’s not scalable, anyway. But this article has highlighted a concern that residents of Anderson Springs, California, near the new drilling site, have had for a while now: that geothermal energy exploration causes earthquakes.
According to a PBS Quest story, California already gets more energy from geothermal sources than from wind and solar. And it’s near Anderson Springs, where AltaRock plans to drill, that much of this energy is derived, through more than 20 power plants in an area called The Geysers.
Calpine, the company that runs The Geysers power system, mines the steam that is readily available within about 8000 feet of bedrock. James Glanz, who wrote the NYT article, says residents have complained for years that drilling by Calpine has led to numerous small quakes that have caused property damage. They worry that what AltaRock wants to do – which involves drilling much deeper into the earth and then pumping cool water down into the resulting fissures, which will fill with steam that will shoot back up to the surface – will cause more frequent and more dangerous quakes.
But AltaRock claims in the article that is has developed a means of drilling deep that won’t trigger strong earthquakes like the one that forced the similar project in Basel to come to a screeching halt. What is less reassuring, however, is that in a safety report that it filed to the US government, AltaRock did not site the drilling activity in Basel and its hasty stop. It does say, on the other hand, that it has “applied for roughly 20 patents on ways to improve the [drilling] method” that was used in Basel.
While AltaRock might have some explaining to do on the safety front, it’s likely not concerned with raising more funds at the moment. “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,” says the article.
The larger issue at hand is whether the numerous other geothermal projects in the works are also vetting the safety issues surrounding drilling-induced earthquakes. The AltaRock project in Northern California may end up being the poster child for current geothermal exploration. If all goes smoothly, it could set a precedent that will send more dollars and attention to the energy source. If something goes wrong, it seems certain that it could mark a major set-back for geothermal.