IRES III 2008, 3rd International Renewable Energy Storage Conference, 24.-25.11.2008, Berlin
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CONCRETE STORAGE FOR SOLAR THERMAL POWER PLANTS
AND INDUSTRIAL PROCESS HEAT
Doerte Laing, Dorothea Lehmann, German Aerospace Center
Carsten Bahl, Ed. Züblin AG
German Aerospace Center, Institute of Technical Thermodynamics,
Pfaffenwaldring 38-40, 70569 Stuttgart, Germany
Phone +49 (0)711-6862-608; e-mail: doerte.laing@dlr.de;
ABSTRACT
Economic storage of thermal energy is a technological key issue for solar thermal power
plants and industrial waste heat recovery. Systems using single phase heat transfer fluids
like thermal oil, pressurized water, air or superheated steam, demand storage systems for
sensible heat. A sensible heat storage system using concrete as storage material has been
developed by Ed. Züblin AG and DLR. A major focus was the cost reduction of the heat
exchanger and the high temperature concrete storage material. For live tests and further
improvements a second generation 20 m³ solid media storage test module was built in
Stuttgart and is cycled by an electrically heated thermal oil loop. By end of October 2008 the
second generation solid media storage test module had accumulated four months of
operation in the temperature range between 300 °C and 400 °C and about 50 thermal cycles
with a temperature difference of 40 K. The tests will be continued until June 2009.
Application fields for the concrete storage technology are parabolic trough solar thermal
power plants; industrial waste heat recovery at elevated temperatures; thermal management
of decentralized combined heat and power systems for increased flexibility and other high
temperature processes. Especially the wide range of possible working temperatures and the
modular structure make the heat storage in concrete attractive.
INTRODUCTION
Low temperature storage systems are based almost entirely on sensible heat storage using
liquid water. For temperatures exceeding 100 °C, non-pressurized liquid water cannot