Siemens said two 7MW prototypes were installed in Osterild, Denmark, for testing. The machine could now enter serial production from autumn 2017.
It is set to be installed at Dong Energy's 330MW Walney Extension East project off the UK's west coast in early 2018.
It was also named as the preferred turbine for Mainstream Remewable Power's Neart Na Gaoithe project off the Scottish east coast, the 294MW Rentel offshore project off the Belgian coast, and for a four-turbine Danish pilot project, approved by the Danish government last week.
Elsewhere, Adwen announced its AD 5-135 turbine has obtained its certification from DNV GL. Adwen is the offshore joint venture set up by Gamesa and Areva.
The 5MW turbine is set to be installed at Iberdrola's 350MW Wikinger project in the German North Sea. Offshore construction at Wikinger is set to begin in March.