Illustration Energiespeicher

The centrepiece of a new power-to-heat plant is a 6-metre-high thermal storage stack.

Heavy industry must find different ways to wean itself off fossil fuels. A new power-to-heat plant developed by Solar Institute Julich (SIJ) at Aachen University of Applied Science with industrial partners, could provide just the solution. The MultiTESS thermal storage system is the first building to be finished at the Brainergy Park site in Jülich and will provide a working model for similar concepts.

The centrepiece of the plant is a 6-metre-high thermal storage stack. Inside is a latticework of ceramic honeycomb bricks with vertical ventilation ducts. The bricks store high temperature heat (up to 1000°C - generated by excess renewable energy sources) that is pumped down from the top during “charging”. When either electricity or heat is required, cooler air is introduced from below and flows upwards, releasing the energy.

The managing director of SIJ, Professor Ulf Herrmann, explains the concept – which he claims is “unique in the world” – in a press release: "The multiTESS concept is the missing link to make the industry independent of fossil fuels such as natural gas... There are many processes in heavy industry that run at very high temperatures. Companies are currently using natural gas to reach this temperature level. We can provide the high temperatures from storage.”

The ceramic brick tower could also be used to store waste heat from industrial processes, as well as feeding lower temperature heat into district heating networks – in other words, the technology could have multiple applications. At the opening ceremony, Oliver Krischer, Minister for the Environment in North Rhine-Westphalia, said TESS could not only be a model for industrial zones, but also for residential settings.

SIJ’s industrial partners are the companies Otto Junker (which developed the high temperature heat concept), Dürr Systems (which provided the ceramic heat storage and the ORC turbine system) and Kraftanlagen Energies & Services, responsible for the overall planning.