In Mainz/Germany the world’s biggest PEM-electrolysis system has gone into production in July 2015 to produce hydrogen.

© Siemens

With a symbolic power-on button in July 2015 the world’s biggest power-to-gas production unit in Mainz has been opened. In May 2014 Siemens, the public utilities of Mainz, Linde and the RheinMain University of Applied Sciences have laid the foundation stone for a new type of energy storage system. With the support of the German Federal Ministry of Economics and Technology as part of the Energy Storage Funding Initiative the 17-million-project as “Energiepark Mainz” could be realized. The system, equipped with an electrolyzer, will convert surplus electricity from wind farms to hydrogen from now on.

“Energiepark Mainz” plays an important role in Germany’s switch to renewables. The world’s largest electrolysis system of its kind converts “surplus” renewables by breaking down water into hydrogen which can be stored for use as and when required. This means greater flexibility in the use of renewables as they will be on hand whenever they are needed.

A hydrogen electrolysis system from Siemens converts surplus electricity to hydrogen in the electrolysis hall. This high-dynamic PEM pressure electrolyser with an input current of up to six MW is the largest of its kind in the world. The Energiepark is thus appropriately equipped in terms of stabilizing the power supply from smaller wind farms.

The PEM-electrolyzer is based on proton exchange membranes. It reacts within milliseconds to the available electrical current — and is thus ideally equipped to handle power generation fluctuations. In Mainz/Germany the world’s biggest electrolysis system has gone into production, which is supposed to produce hydrogen from surplus wind energy . But additional electricity must be acquired on the market.