The world market leader for solar district heating systems, Arcon-Sunmark, has now installed its first solar thermal system for a German district heating system in Berlin-Köpenick.

The solar plant, which has 78 large collectors has a total gross collector area of 1,058 m², is ground mounted on the premises of the combined heat and power plant of the energy company Vattenfall in Berlin-Köpenick. The collectors feed its energy into the return pipe of the Köpenick district heating system throughout the year using a heat exchanger without a storage tank. With this method the highest solar yield can be fed into the grid, explains Christian Stadler, Managing Director of Arcon-Sunmark’s German representation. Vattenfall had checked a solar feed-in into the supply pipe for the summer months by simulation, but finally rejected, as also the return feed-in had no effects on the efficiency of the connected CHP plant. This is mainly due to the size ratio between the huge district heating system of Berlin-Köpenick and the collector system, which is rather small for the Danish manufacturer’s standards, Stadler reports.

In this way, the system makes a considerable contribution to the district heating demand, especially in the summer, says Stadler: “For us, this system is important because it shows that solar thermal energy also works in the urban district heating of large cities in Germany. And by the way, in 90 percent of the cases – as in this example – we also find a solution for the land problem together with the supplier.”

Text: Guido Bröer, translated from the German original
Picture: Vattenfall