Substation Z60 becomes an energy center

The idea: Local solar heat for direct use in urban apartment buildings

A large district heating network with several secondary networks has been implemented by Wagner Solar in the city of Chemnitz.
The energy supplier „eins“ took the opportunity to revolutionize the heat supply during the renovation of the inner city district of Brühl. In cooperation with the city administration and supported by the TU-Chemnitz Chemnitz is now one of the pilot projects of energetic urban regeneration. New district heating pipes were laid and a 2200 m² solar thermal system from Wagner Solar was installed in combination with a CHP unit. Our WGK collectors, which were specially designed for large installations were used. The collector system is designed as a free-standing system. Sigma ram-profiles or Steel Roots foundations have been used for windproof installation, this allows an individual height adjustment. The collector connectors reliably compensate for the length expansion of the collector cables pre-assembled in the collectors. For example, long collector rows of up to 120 m² can be directly connected to one another without any additional piping. The Z90 energy center was located at the location, directly at the residential quarter, which is also operated centrally by a cooling supply. Currently, 168 buildings are being provided with about 1,600 households. The heating load is 9 MW. In total construction, the heating load will rise to 15 MW.

Create the best conditions

In order to be able to utilize solar heat optimally, the temperatures must match. As part of the redevelopment of the whole district with TU-Campus and the Brühl Boulevard, the infrastructure ( gas & water supply as well as the communication) has also been modernized. The energetic optimization of the buildings and of the distribution now allows flow temperatures of 70 ° C and return temperatures of 35 - 40 ° C separated by heat exchanger from the district heating network. The special feature here is that the secondary network is used without system separation from the collector field to the radiator. Higher yields due to lower system temperatures and reduced system costs due to simpler design overcompensate the active frost protection by heating the collector field with low-temperature heat in the few frost pits. The facility was completed in August 2016. A successful example for the successful integration of large solar thermal systems in urban areas.