Germany’s current largest solar thermal collector array provides in combination with two buffer storage tanks and a borehole thermal energy storage (BTES) system about the half of the local heating requirements of a recently built housing estate in Hirtenwiesen, Germany.
The solar thermal energy will cover 50% of the heating requirements of this residential area. To ensure that this is possible throughout the year, a seasonal borehole thermal energy storage system has been installed. This is the most cost-effective version to be produced so far.
One third of the 7,400-square-meter collector surface area has been installed on the roofs and two thirds on a noise protection barrier. The solar collectors feed their heat into a small and large buffer storage tank. The large tank is connected to the borehole thermal energy storage system, whose size corresponds to a water equivalent of 10,000 cubic meters.
The BTES system can be expanded when the housing estate grows, and can also act as a multifunctional storage system for absorbing waste heat from combined heat and power plants.