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Climate-friendly heating: Several cantons are promoting lake thermal energy. But there is a problem.
Because of the war in Ukraine, energy prices are going through the roof. Many homeowners and companies could experience their blue miracle with the next heating oil bill. Renewable energies such as photovoltaics or geothermal probes are an alternative.
What many people don’t know is that if you live by a lake, you basically have a huge heating and air conditioning system right outside your front door. Lake thermal energy, i.e. the generation of energy from lake water, has great potential. A study by the canton of Thurgau in 2021 showed that the use of lake heat could replace around 10 percent of the energy that is currently obtained from natural gas or oil.
There are therefore corresponding lake thermal energy projects throughout Switzerland, for example on Lake Wohlen near Bern, on Lake Zurich, on Lake Constance, on Lake Zug or on Lake Geneva. The country’s largest lake thermal project is currently being built on Lake Lucerne, which is intended to supply 7,000 households with heat.
Biel wants to supply the university campus with sea energy
The impending gas bottleneck is giving the Seethermie tailwind. Another major project is being built in the Biel region: the lake thermal system on Lake Biel costs 50 million Swiss francs. This will be used to heat and cool around 1000 residential units near the lake in Biel and Nidau from next autumn.
Legend:
More than just a beautiful view: energy will soon be generated from the water of Lake Biel.
key stone
A project like this takes staying power, says Martin Kamber, Managing Director of the Bielersee Energy Network. The first ideas were already circulating in 2014, shortly afterwards the Bern University of Applied Sciences expressed its interest in heating the new campus near the lake with renewable energy and also cooling it in summer. According to Kamber, only this dual use makes the lake thermal project economical for the energy network.
But because of an expropriation dispute with a property owner, the start of construction was delayed further and further. In the worst case, the start of construction could be delayed until 2026. It’s annoying, but you have to live with it, says Kamber. The infrastructure has been under construction since last summer so that the first houses in Nidau and Biel can be heated with lake water from autumn.
Disillusionment at Lake Thun
The situation in Spiez on Lake Thun looks a little different. “Insufficient heat density near the lake, therefore not economical,” was the sobering conclusion of a feasibility study. More and larger buyers of this energy would be needed for a lake thermal project to make economic sense.
Legend:
A lake thermal power plant is also to be built below the Niesen in Spiez.
key stone
The responsible Spiez councilor Marianne Hayoz Wagner does not want to write off the lake thermal energy – precisely because of the current developments on the energy market. According to Wagner Hayoz, lake thermal energy also means less dependence on foreign energy sources. “That’s why local heat could become more attractive and soon be more competitive on the market.”