The second section of the Borkum Riffgrund project will use the new 8MW wind turbines from MHI Vestas. The joint venture was named as preferred supplier in June.
Borkum Riffgrund is located in the German North Sea, 57 kilometres from shore in depths of around 25 metres. It is set for completion in 2018.
Dong Energy has yet to make the final investment decision on the project.
Borkum Riffgrund 1 comprises 78 Siemens 4MW turbines, which were fully installed in May. The project is expected to be fully online later this year, said Dong Energy.
The Danish utility took full ownership of both projects in 2009, when it bought out PNE Wind's share of the sites. In line with its strategy to part-own projects once completed, it has since sold on part of Borkum Riffgrund 1 to Lego parent group Kirkbi AS, and the Oticon Foundation.
When announcing first-half financial results last week, Dong CEO Henrik Poulsen said of future ownership arrangements for offshore projects: "You can expect us to continue this strategy."