Drilling rig being set up for Lavey-Morcles geothermal project, Switzerland

The Lavey-Morcles geothermal power plant project in the canton of Vaudoise in Switzerland is entering a concrete phase, as reported locally. Last week, the gigantic drilling rig with a weith of 89 tonnes was sent to the site at Chablais vaudois.  The heavy truck with nine axles moved the drilling rig from the Netherlands. The next step is to set it up for a planned drilling start in a couple of weeks. We previously reported on the drilling contract that was signed with German drilling company Daldrup & Söhne AG.

“Drilling should begin during the third week of January and will last around six months”, specifies Jean-François Pilet, director of AGEPP SA, in charge of the project. This will be the first deep geothermal project in Switzerland for the rig, as the drilling rig will then be transported to La Côte for a similar concept planned in the Vaud municipality of Vinzel. A third project could follow in the Jura, in the town of Haute-Sorne.

At Lavey-Morcles, the plan is to drill to a depth of 2.3 km to capture water at a temperature of 110 degrees Celsius with a flow rate of around 40l/ seconds.  The drill chosen, unmatched in Switzerland, can even reach 3,000 meters underground. This quantity of water will supply the thermal baths at Lavey-les-Bains and will produce the equivalent of the electricity consumption of 900 households per year.

In the long term, it is envisaged to enhance the waste heat for other uses (heating remotely, greenhouses, farms, etc … ). “From the end of 2022, the Baths will no longer be supplied with hot water by the three current wells which will be kept as emergency structures, but directly by the new construction. We will then have to wait until the end of 2023 for the installation to generate electricity (4.2 GWh per year), ”confirms Jean-François Pilet.

The current cost of the project is around CHF 40 million (ca USD 43.4 million). It benefits from two grants: one from the Federal Office of Energy (for around CHF 17 million), the other from the State of Vaud (CHF 1.5 million). The balance is the responsibility of the project partners including EOS, CESLA, Romande Énergie, Holdigaz and the municipalities of Lavey-Morcles and Saint-Maurice (VS).

“There are no seismic risks”

Several deep geothermal projects have had to be aborted in the past. Drilling had caused earthquakes. In Basel , they were stopped after a series of earthquakes – four in less than two months – in 2006. And it was in 2009 that the Basel government finally decided to abandon its project. Even after the work was stopped, many aftershocks were felt. In 2013, in the canton of St. Gallen , a borehole caused similar problems. More recently, in 2020, it was the canton of Jura that expressed its concern, concerning the Haute-Sorne project. But, as regards Lavey, Jean-François Pilet is confident: “there are no particular seismic risks expected.” The big difference between this last project and the previous ones is that the rock is already naturally fractured this time. It is therefore not necessary to artificially fracture it with injections of water, a trigger for earthquakes. Note that, in early 2020, Italian researchers managed to dig up to 3,000 meters underground, without triggering earthquakes.

Source: 20min.ch