Using power from renewable energy sources, the plant will produce about 360 m³ (30 kg) of hydrogen per hour from 2013 onwards through electrolysis. The hydrogen will be fed into the Ontras gas pipeline system and be used like normal natural gas. This makes the gas grid a storage system for power from weather-dependent renewables.

At present, up to 5% hydrogen can be added to the natural gas grid without any problems, and in the medium term experts expect up to 15%, E.ON said; today’s entire renewable power output could be stored in the German gas grid. Demand for capacity on this scale will however only arise over the next decades, when most of generated power is coming from renewable energies, according to E.ON.

We need new storage capacities so that we can further increase the share of weather-dependent wind power in our generation portfolio in coming years. Using the existing gas infrastructure to store hydrogen is a promising approach in the long run, enabling us to combine our strengths as a power and gas company.

—Professor Klaus-Dieter Maubach, member of the E.ON AG Board of Management responsible for Technology & Development

If Germany increases the share of fluctuating wind and solar energy in power generation in the years ahead, the power available will at times exceed demand and bring the power grid to the limits of its capacity. E.ON is therefore investing in technology to store this excess power. At the moment, the focus is on enlarging the capacity of pumped-storage power stations. For instance, EON intends to extend the pumped-storage power station at Edersee in the federal state of Hesse and—together with its partners—build a new plant on the German-Austrian border.