German workers ‘trigger’ earthquake by drilling
(TIMES ONLINE) Officials in Germany have launched a safety review after underground drilling by a geothermal energy company is thought to have triggered an earthquake.
Local government officials in the city of Landau in der Pfalz believe the quake on August 15 was caused by a geothermal power station designed to tap heat from deep below the earth’s surface.
Geox, the German company that built the plant, uses a technology that involves drilling holes up to 5,000 metre deep and injecting them with water, producing enough steam to drive turbines and generate electricity.
Supporters of the technology say it promises to unlock huge supplies of clean, low-carbon energy that could help wean the world off fossil fuels like coal and oil.
But the incident in Germany follows a spate of similar incidents in the US and Switzerland which have raised concerns about the safety of geothermal energy projects.
The quake in the province of Rheinland-Pfalz close to the French border took place just after 2pm on a Saturday afternoon and was accompanied by a loud boom. It prompted about 200 calls to the local police.
Although it registered just 2.7 on the Richter scale and caused no injuries or damage, local officials have responded by launching a safety review board which met for the first time on September 4.
The state geological survey for Rheinland-Pfalz claimed the epicentre of the quake lay just 500 yards from the plant’s drilling site and at about the same depth as a steam reservoir that the plant was drawing heat from.
Rudolf Braun, an expert in the safety of geothermal energy projects, there was no question that geothermal energy projects were capable of triggering small earthquakes.
“You need to have some weak earthquakes in order to create a geothermal reservoir containing enough water to generate commercial amounts of power,” he said. “You need to have some small seismic disruptions to achieve this. So the question is not whether or not they cause earthquakes but to what degree they might cause damage.”
Professor Braun is producing a report later this year into similar series of quakes that hit the city of Basel in Switzerland in 2006 and 2007.
The US Department of Energy is examining another project led by a company called AltaRock in California.
Geox’s Landau plant, which is sponsored by Germany’s environment ministry, cost $30 million to build and entered service in 2007. It generates electricity for 6,000 homes.
Officials from the company could not be reached for comment yesterday. So far they have declined to comment on whether or not the quake may have been triggered by drilling at the plant.