Saft has supplied its Uptimax nickel battery systems to E.ON’s Amrumbank West offshore windfarm.

The recently-inaugurated 302 MW windfarm is about 40 km from Helgoland, an island off the coast of Germany in thE.ON’s Amrumbank West windfarme North Sea.

Its remote location meant that E.ON needed backup batteries that would guarantee reliable and safe operation without the need for regular maintenance visits.

The power systems supplier for the project, Benning of Belgium, picked Saft’s Uptimax battery, which offers up to four days of backup power, minimal maintenance requirements and a long shelf-life.

Saft subsequently provided 80 of the battery systems – one for each turbine. In the event of an interruption to the main power supply, the batteries are designed to deliver peak power for essential safety systems for an initial period of eight hours, followed by a further 88 hours of low power. Each battery is rated at 24 V and has energy storage capacity of 150 Ah or 390 Ah.

Saft said that the nickel batteries will reduce E.ON’s requirements for maintenance visits by helicopter and will require no topping-up for their entire 20-plus-year lifetime.