Climate-friendly district heating in Leipzig: One of four work packages within the framework of the SPARCS subproject for the development of energy-positive residential buildings studies how this goal can be achieved. Leipziger Stadtwerke is in charge of its implementation: As part of an innovative CHP system, the company will build one of the largest solar thermal energy plants in Germany in the western municipal district (locality of Lausen-Grünau) – and has now also been successful in the tendering procedure of the Federal Network Agency. The news on the successful tendering for iCHP was received in December 2020 and the next planning steps are already being prepared.

The solar thermal energy plant is funded as part of an innovative combined heat and power system (iCHP), which also comprises a cogeneration power plant (Cogeneration Plant Leipzig Northeast) and a power-to-heat unit. The latter and the solar thermal energy plant belong to the SPARCS work package “Zero CO₂ district heating in West Leipzig”, but is implemented jointly with the iCHP-funded cogeneration plant on the premises of Leipziger Stadtwerke on Heiterblickstraße in the eastern part of the city. The SPARCS project share comprises the planned integration of the two units into a new digital platform, the so-called “virtual power plant”. This means that several decentralised generation plants are pooled virtually to form a larger generation unit – permitting more efficient control and operation of the individual plants.

The iCHP system – including the solar thermal energy plant – is a stepping stone on the way to a climate-neutral heating supply in Leipzig, which the transformation plan for district heating of Leipziger Stadtwerke intends to achieve by 2040. During the summer months in particular, solar thermal energy can meet a significant share of the demand for district heating.

The solar thermal energy plant Leipzig West is to be constructed on a 14-hectare plot in the southwestern part of the city. Leipziger Stadtwerke successfully concluded a contract for the area at the beginning of the year. Situated directly adjacent to Lausen substation, the Cogeneration Plant West currently under construction and a district heating route of Leipziger Stadtwerke, the area – previously used for agriculture – is to become home to one of the largest facilities of its type in Germany. At the same time, it will be particularly eco-friendly: While the collector panels are normally installed close to one another and at a minimum height of 60 centimetres, the plant at Leipzig-Lausen will feature wider gaps and a minimum installation height of 80 centimetres. This means that animals and plants will have enough space in between and below to thrive. It is currently being studied which animal and plant habitats are particularly beneficial to biodiversity or the microclimate, for example. Among the available options are flowering meadows, bushes or also natural stone piles which can offer insects, birds and other animals a habitat free from chemicals and fertilisers. Sheep will be used as “mowers” – this is why the collector panels will be installed relatively high.

In order to achieve an optimal combination of economy and ecology, the city planning authority and Leipziger Stadtwerke’s project team in the staff for the establishment of new generation systems are currently working on several development options, which will ultimately be decided on by the city. The according approval planning is already in the works, as is the detailed technical planning. Provided that everything goes according to plan, the latter will be complete by the end of 2021. The EU-wide invitation to tender is scheduled for Q4 of 2021. The outcome is expected in early 2022, allowing construction work to start still in the same year.