The large-scale facility of the DLR Institute of Engineering Thermodynamics in Stuttgart is used for the development of new thermal storage system based on directly flowing solids. Different storage structures, operating modes, storage materials, isolation structures and electric heating concepts for high-temperature applications above 500 degrees Celsius are being tested for this purpose.

The operating range of the system allows a high level of flexibility in test operation, as all of the decisive operating parameters, such as temperature, pressure, throughput and humidity, are variable across a wide range.

The core element of the system is a solid storage tank for operation with hot air at adjustable pressure. The vertically suspended storage container, which is about 5 metres tall, contains a replaceable inner container. A heating component integrated into the loading line allows the investigation of new power-to-heat concepts for the external heating of the fixed bed to a pilot plant scale. The testing of power-to-heat solutions in combination with high-temperature storage provides conceptual proof of functionality and operating behaviour.


Volker Speelmann

Head of Research Infrastructures
German Aerospace Center (DLR)
Executive Board department for Innovation, Transfer and Research Infrastructure
Linder Höhe, 51147 Cologne

Stefan Zunft

German Aerospace Center (DLR)
Institute of Engineering Thermodynamics
Thermal Process Technology
Pfaffenwaldring 38-40, 70569 Stuttgart