Geothermal energy is an inexhaustible energy source! And the best part is: it can be used year-round, regardless of the seasons. Geothermal energy utilizes a powerful pump that brings warm, very salty water to the surface for heat generation. This salty deep water is called brine.

The brine originates from a riverbed dating back to the dinosaur era. Due to the heat within the Earth's interior, the brine beneath Schwerin is 56 degrees Celsius at a depth of 1,300 meters. The thermal energy of the brine makes its extraction worthwhile. This thermal energy is extracted through heat exchangers. Since the brine is very salty, it is aggressive and could cause corrosion damage to the technical equipment. Therefore, in the heat exchangers, the heating water is warmed without direct contact with the brine.

In this process, the brine cools down to about 20 degrees Celsius. It is then transported to the Lankow Sports Park via the brine pipeline and reinjected into its original rock layer through the injection well, creating a closed cycle.

Back at the geothermal heating plant: the heating water, already warmed to about 56 degrees Celsius by the heat exchangers, flows into the heat pump room. Here, four high-performance heat pumps environmentally increase the existing temperature to up to 82 degrees Celsius – sufficient for the summer operation of Schwerin's district heating network. When it's cold outside, the district heating water needs to be significantly hotter before being fed into the network. In that case, the temperature is increased up to 130 degrees Celsius at the neighboring Lankow heating plant and then distributed via the district heating network.

In April 2023, the Schwerin utility company inaugurated its first geothermal plant in Schwerin Lankow in the presence of Federal Chancellor Olaf Scholz and Prime Minister Manuela Schwesig. The plant has a heat output of seven megawatts. What's special about it is the first-ever combination of medium-depth geothermal energy and heat pumps in Germany. This combination is specifically adapted to the regional conditions of the North German Basin, making it a flagship project for further initiatives in the region.

Focus on Climate Protection

The heating market plays a crucial role in climate protection, accounting for about 40 percent of energy-related CO2 emissions in Germany. Thus, there is significant potential for CO2 savings in this sector. One approach is the decarbonization of heat, where fossil fuels are replaced with renewable energy sources to reduce or even eliminate greenhouse gases. The decarbonization of heat is essential for the heat transition and the broader societal goal of climate protection. Schwerin has made a significant milestone on this path with its first geothermal plant, Lankow I. This plant enables the utility company to save 7,500 tons of CO2 annually.