The development of a thermo-mechanical energy storage system (TMS) by the four-person team from the Institute of Process Engineering, Process Automation and Metrology (IPM) at the HSZG and the partner company Spilling Technologies is based on considerations that began around 100 years ago. It was then that Dr. Fritz Marguerre secured his process and the device for storing energy. The conversion of electricity into steam played a decisive role in his invention.

So far, so good, but his patent disappeared into the drawers of history and the machine was never built because its low efficiency meant that it was not worth developing at the time.

Now we are faced with the challenge of having to temporarily store electricity from renewable energy sources so that it is available when we need it. This is the only way we can achieve the energy transition and thus a future without fossil fuels.

In addition to battery storage and the emerging industry of the hydrogen economy, old-fashioned steam, which already got industrialization going in the 18th century, is a candidate that is worth more than a quick look. A kind of "modern steam" for the 21st century is needed!

Sebastian Braun, an engineer at the IPM, has further developed Dr. Marguerre's idea of storing energy in steam. Now the TMS should be able to do even more. At its heart is a multi-cylinder piston engine that can be operated both as a heat pump (compressor) and as a heat engine (expander). Electricity is no longer just stored in steam, but also converted back into electricity.

In contrast to current battery storage concepts, whose raw materials are extracted and processed at great expense, the TMS uses water and steel, sustainable materials that are available in sufficient quantities. It also scores points over batteries in terms of the recycling process.

The idea also convinced the Federal Ministry of Economics and the partner company Spilling Technologies GmbH. Together, the team is now in the starting blocks to jointly develop, experimentally investigate and optimize the first thermo-mechanical electricity storage system in Europe - probably even in the world.

This means more steam for the urgently needed energy transition than Dr. Marguerre could ever have imagined for his thermo-mechanical electricity storage system in the 1920s. In short: the medium of steam is alive!