Installation of half the total 30 wind turbines has been completed at the 108MW Riffgat wind farm, according to majority owner company EWE.
EWE technical project manager Irina Lucke said installation work is already underway on the remaining turbines. The whole project is due for completion in mid-July 2013.
Riffgat will be Germany's first North Sea commercial-scale offshore wind project to be completed. It uses Siemens SWT-3.6-120 turbines.
On average, installation of each tower, nacelle and blades requires one day, depending on wind conditions, the company said. The heavy-lift installation vessel Bold Tern is working out of the Danish port of Esbjerg and can transport the components for eight complete turbines.