Test Results of Concrete Thermal Energy Storage for Parabolic Trough Power Plants

Efficient energy storage is vital to the success of solar thermal power generation and industrial waste heat recovery. A sensible heat storage system using concrete as the storage material has been developed by the German building company Ed. Züblin AG and the German Aerospace Center (DLR). A major focus was the cost reduction in the heat exchanger and the high temperature concrete storage material. For live tests and further improvements, a 20 m3 solid media storage test module connected to an electrically heated thermal oil loop was built in Stuttgart. The design of the test module and the test results are described in this paper. By the end of November 2008, the second generation solid media storage test module had accumulated five months of operation in the temperature range between 300°C and 400°C and almost 100 thermal cycles with a temperature difference of 40 K. The tests will be continued in 2009.