Geothermal plan in doubt after tremors

BASEL (Reuters) – Efforts to tap energy deep below the earth’s crust to provide power for homes in the Swiss city of Basel may have to be scrapped after setting off tremors.

The plan to use geothermal energy to generate electricity for 10,000 homes and heat for 2,700 others is on hold after it caused earth tremors twice in less than a month, prompting frightened residents to flood emergency services with calls.

“We had expected the experiment to cause minor tremors. But so far we do not know in detail why the quakes were bigger than expected,” said Stefan Wiemer of the Swiss Seismological Service.

In the Swiss model, geothermal energy is generated through high-pressure injection of water into hot granite at a depth of 5,000 metres. This produces steam used to drive turbines.

Reuters