Earthquakes trigger concern over geothermal power

The two biggest geothermal projects in Switzerland have caused earthquakes. One project was halted as a result but another is still underway. Critics want further projects stopped. (SRF/swissinfo.ch)

Geothermal energy is an inexhaustible, clean and constant energy source. By the year 2050,it’s hoped that up to 10 % of the country’s energy needs will be covered by around 200 geothermal energy stations. But there’s still a lot of uncertainty about its cost and safety. The injection of fluids into hot rock can cause fracturing, which can generate low magnitude seismic activity. Drilling in Basel several years ago caused a series of earthquakes, some greater than magnitude 3. The project had to be stopped. Boring work on a different project in St Gallen in summer this year triggered another earthquake. Measurements taken by the Swiss Seismological Service showed that after drilling stopped there were hundreds of aftershocks. They said these could continue for months or years. While energy specialists seem to agree that geothermal power has potential benefits, not everyone believes it should have a priority for funding over other renewables. Further geothermal projects are being planned in Switzerland at the moment.