Research project mi H2DRY plant entering the next phase

• Hydrogen storage as a flexibility option for green energy
• Joint research to drive forward sustainable solutions
• Use of existing natural gas infrastructure

The current construction and subsequent operation of Bilfinger's H2dry plant at the energy service provider EWE's gas storage site in Rüdersdorf near Berlin marks the beginning of the next phase for the future possible storage of hydrogen in underground caverns.

Green hydrogen available on demand

The storage and retrieval of hydrogen in cavern storage facilities - similar to natural gas - can contribute to creating additional flexibility in an energy system based on renewable energies in the future. The energy from green electricity is converted into hydrogen using electrolysis. If this can be stored in underground cavern storage facilities, for example, its contained energy can be used as needed. EWE is currently working on realizing this option in the "HyCAVmobil" research project in Rüdersdorf, Brandenburg, funded by the German Federal Ministry of Digital Affairs and Transport as part of the National Hydrogen and Fuel Cell Technology Innovation Program. The hydrogen test cavern, with a volume of around 500 cubic meters, was completed a few weeks ago. This was preceded by extensive, successful leak tests of the supply line to the cavern down to a depth of 1,000 meters.

For the initial filling with hydrogen, EWE is currently installing the above-ground technology for hydrogen storage. The hydrogen drying plant developed by Bilfinger, a so-called H2dry plant, will also be used. Its technology is designed to enable the economical and efficient treatment of hydrogen on a large scale, because after storage in caverns in deep rock strata, the hydrogen has to be dried for further use.

Gaining knowledge from the research cavern

The initial hydrogen filling of the research cavern is planned for late summer. Through the subsequent interplay between injection and withdrawal of the hydrogen, Bilfinger and EWE will gain results in the following months that can be transferred to caverns with 1,000 times the volume. With 37 salt caverns, EWE alone has more than 15 percent of all German cavern storage facilities that are suitable for storing hydrogen in the future.

The drying process

The H2dry plant developed by Bilfinger is used to dry hydrogen. Project partners for the implementation of the sub-project within the EWE research project HyCAVmobil include the Institute of Thermodynamics at Leibniz University in Hanover. In the new process, hydrogen is dried by absorbing moisture using a suitable scrubbing liquid. In this method, Bilfinger draws on its many years of experience and expertise, which has already been applied on a large scale for natural gas in gas storage and has been characterized by reliability and efficiency for decades.

Quotes:

"We have gained experience in the development of gas drying plants throughout Europe over the past decades. This now enables us to help shape the energy transition through the use of green hydrogen."

Karsten Hoffhaus, COO Bilfinger Engineering & Maintenance GmbH

"Large cavern storage facilities may be suitable for storing hydrogen in the future. This would make green hydrogen produced from renewable energies storable in large quantities and usable as needed, and would become an indispensable component for achieving set climate targets and diversifying and securing future energy supplies."

Peter Schmidt, Managing Director EWE GASSPEICHER GmbH.