Lake in former coal mine to host new large heat pump for eastern German city

The eastern German city of Cottbus in coal mining region Lusatia plans to use an artificial lake in a former open pit mine for the installation of a large heat pump that could cover up to 40 percent of the city’s district heating, news website Focus Online reports. About half of the city’s 100,000 inhabitants are connected to the district heating grid, which is currently linked to the nearby Jänschwalde coal plant. The plant is planned for decommissioning by 2028. The new heat pump could be installed in the Cottbuser Ostsee, Germany’s largest artificial body of water located in a former lignite mining pit that was flooded in 2019. “The lake is a giant heat collector,” said Vlatko Knezevi, head of Cottbus’s local utility. Applications for the installation with a capacity of 35 megawatts will be submitted soon and construction costs are estimated at about 80 million euros. During a visit to Cottbus, Germany’s foreign minister Annalena Baerbock said the project provided a good example for the country’s ambition to leave coal-fired power production in the 2030s. “This means there need to be investments in alternatives and that we have to lay the financial groundwork this year,” the Green Party politician argued. Baerbock added that the government would coordinate efforts at the regional, national, and the EU level to quickly secure funding for the heat pump.

Several German cities have started to install large heat pumps as part of their efforts to make their heating systems fossil fuel-free. A new law introduced by the government in 2023 obliges cities to present a strategy for decarbonising their heating supply. Other options to spur a transition in the heating sector in cities include geothermal power or waste heat.