The 6.15MW turbines are being installed at water depths of 22 to 25 metres at the site about 35km north of the island of Heligoland.

The wind park is expected to be commissioned in the spring of 2015.

“We are delighted that the first turbines for Nordsee Ost are now in the water," Senvion chief executive Andreas Nauen said.

"A successful energy revolution needs onshore and offshore and wind power in general needs reliable conditions.