Fear of earthquakes halts promising geothermal projects
Sep 14th 2009 1:20PM
Updated Dec 4th 2009 3:23PM
Not too long ago green energy activists hailed geothermal power as the best way to generate cheap, clean power with minimal environmental impact or carbon emissions. That view has been thoroughly shaken by incidents around deep-drilling geothermal projects linked to nearby earthquakes.
Now energy authorities fear that harvesting subterranean heat might not be quite as safe as originally thought. On September 2, AltaRock Energy halted a $17 million pilot project in California that was a geothermal showpiece and a significant hope for quickly tapping geothermal energy to replace fossil fuels.
The project was halted after significant difficulties in drilling. AltaRock had fallen far behind schedule and had only managed to drill 800-feet down from its original starting point of 232,00 feet. The well needed to go 12,000 feet down to tap into thermal reserves that would have been used to turn turbines on the surface and generate electricity. Another geothermal project, in Switzerland, was feared to have helped cause local earthquakes, according to TreeHugger.com.
The attraction of geothermal to clean energy fans has made this form of power generation a favored alternative. Unlike coal or natural gas, geothermal does not burn anything and, therefore, does not release significant additional carbon into the atmosphere. Likewise, geothermal does not release pollutants, such as mercury and other heavy metals associated with burning coal. Unlike solar or wind power, geothermal runs around the clock and is not weather dependent. And according to some recent research by MIT, geothermal is the most cost-effective alternative energy method presently available.
But geothermal has had a tough road to mass adoption. In Hawaii, native Hawaiians and environmentalists have opposed expansion of a profitable geothermal plant there due to concerns that an expansion would disturb sacred cultural grounds and could negatively impact native species. Hawaii has the highest power costs in the country and it also is the most reliant on imported oil for power generation and other key economic activities. All oil and gas comes in on a boat, as Hawaii has no contiguous petroleum production.
Others fear that geothermal could prove to annoy Mother Nature and unsettle delicate geological balances, resulting in temblors. Most geothermal plants are located in areas of relatively significant volcanic activity, which has led to some concerns that an eruption could cause a sudden power loss if a plant was forced to shut down.
By the same token, volcanically active areas tend to also be geologically active and so some opponents have worried that quakes could take down geothermal plants and release into the local atmosphere unhealthy gases piped in from the deep Earth as part of the thermal harvesting.
For coal companies, the slowdown of geothermal development is probably good news, as this type of energy generation could present the most significant competition to date for power generation.