Solving the weak grid problem in Germany

A battery system capable of storing up to 1.6 MWh of wind power is being tested in the German state of North Rhine Westphalia at a new wind plant near Bocholt. Four turbines, with a combined installed capacity of 3.56 MW, feed power to the storage unit because the local utility, Bocholter Energie und Wasserversorgung (BWE), will only contract for 2 MW. According to the battery system's developer, the device can solve the problem of the Bocholt area's restricted grid capacity. The developer, based locally in Gelsenkirchen, calls itself EUS, an acronym for Gesellschaft für Innovative Energieumwandlung und Speicherunga, or innovative energy conversion and storage.

The wind plant consists of two Tacke TW 1.5 MW units, a WindWorld 500 kW turbine and a Tacke 60 kW turbine, all operated by Windenergie Knaup. In periods of high wind power production, the surplus is stored and later released in periods of peak demand. This allows BWE to cover its peaks with wind power instead of buying in electricity elsewhere. For this "embedded generation" value the utility pays Windenergie Knaup a bonus in addtion to the set REFIT tariff, the amount of which it declines to disclose. When the battery is full and consumer demand is low, the output of the turbines is regulated.

The wind battery system is the second renewables storage system by EUS. The first stores up to 1.2 MWh of solar energy for the utility of Herne. The battery systems cost DEM 1.8 million each. Windenergie Knaup met 51% of the costs of both projects together with the town of Bocholt and the Herne utility; 49% is from EU funds and a regional energy program, the Landesinitiative Zukunftsenergien.