Leipzig's largest solar thermal system: Green heat turbo for the city!

Leipzig's largest solar thermal system: Green heat turbo for the city!

In recent years, the expansion of solar thermal systems has become more important in Germany. This technology could make a decisive contribution to the decarbonization of district heating supplies. The country's largest solar thermal system with a peak output of 41 megawatts is currently being built in the Lausen-Grünau district of Leipzig. The Leipziger Stadtwerke invested 40 million euros in the project, of which 16 million euros came from funding, such as Climate reporter reported.

The new system will use plastic casing pipes that provide excellent thermal insulation. Warm water at a temperature of 60 degrees Celsius is transported to the collectors, where it is heated up to 113 degrees. The heat obtained there is then passed on via a pipe system to a technical building, where it is transferred to heat exchangers. The commissioning of this large-scale solar thermal system is planned for May 2026. In summer it is expected to cover a fifth of Leipzig's district heating needs, but this only corresponds to around two percent on average for the year.

Potential of solar thermal energy

The Steinbeis research institute Solites describes that there are currently 61 solar heating networks in Germany with a total peak output of 121 megawatts. What is particularly interesting is that the total collector area of ​​solar heating networks could potentially be doubled by the end of 2025. There are currently 13 additional collector fields with a total of 153,000 square meters of collector area under construction or being planned. Speeding up approval processes could support this process, such as Renewable energy emphasized.

Dirk Mangold, scientific director of Solites, emphasizes that stronger market growth is required to exploit the potential of solar thermal energy. Experts from the SolnetPlus project see the new heat planning law, which came into force at the beginning of 2024, as an important step to give grid-connected solar thermal energy a further boost.

Political framework conditions

Municipal heat planning plays a central role in the development of solar heat networks. This is intended to help identify and resolve usage competition at an early stage. It should also be noted that federal funding for efficient heating networks is available until September 2028, which could further support the expansion of such projects. Prognos assumes that large-scale solar thermal energy would have to produce four million megawatt hours of district heating annually in order to convert heat supply completely to renewable energies by 2045.

Overall, it can be said that solar thermal energy in Germany is facing a decisive turning point, which is being favored by both technological advances and political framework conditions. The required expansion and accelerated approval of solar heat systems are essential factors in achieving the goals set for environmentally friendly heat supply. In summary, it can be said that a doubling of collector areas by 2025 has become realistic, which could represent a significant development for the energy transition.