Fraunhofer IISB builds long-term energy storage with hydrogen technology

14 augustus 2017

The storage system is being set up as part of the LZE pilot project “DC backbone with electricity-gas coupling”. The 20 foot container is being built in close collaboration with the Fraunhofer institutes IISB and IIS with the Friedrich Alexander University Erlangen-Nuremberg (FAU) and regional industrial partners. The basic concept is to generate hydrogen from excess electrical energy, for example from a local photovoltaic system, and to store safely and compactly it in an organic carrier – even over extended periods of time. For later use, the hydrogen can be released from the carrier again and converted into electrical energy by a fuel cell. The fuel cell was put into operation as early as April 2017 as the first main component of the energy storage system. The fuel cell system provides 25 kilowatts of output capacity and is based on the so-called low-temperature PEM technology (PEM: Proton Exchange Membrane). The PEM design basically allows the fuel cell to be switched to its operating state within a few minutes from the switched-off state. Fast operational readiness is forinstance important for the future coverage of load peaks in industrial machines.

The liquid carrier used for hydrogen storage is known in the technical field as LOHC (Liquid Organic Hydrogen Carrier). The Erlangen researchers see great potential in the LOHC technology, a specialty of the Chair for Chemical Reaction Engineering (CRT) at the FAU. The liquid carrier takes up large amounts of electrolytically produced hydrogen via a chemical reaction and can then be stored safely under normal ambient conditions for pressure and temperature. Only under very specific conditions within a chemical reactor can hydrogen be released from the carrier again.

In the container in Erlangen, about 300 liters of LOHC are currently used, which corresponds to an energy content of the stored hydrogen of almost 600 kilowatt hours. This is sufficient to cover the power requirements of a smaller industrial plant over several hours. However, the stored energy can easily be increased several times by means of additional tank containers. Thus, also larger enterprises such as data centers or hospitals can be supplied over longer periods of time.

The whole article can be found here.