The first of 150 Siemens 4MW turbines have started producing power from the site, 85km from Groningen on the Dutch coast.
Turbine installation began on 16 February, according to WPO Intelligence, the research and data division of Windpower Offshore.
The turbines are being loaded out at the Port of Esbjerg and installed from the Aeolus and the Pacific Osprey vessels. Dutch engineering firm Van Oord is the EPCI contractor for the 600MW project, which is due for completion in 2017.
The 600MW Gemini project "continues to advance on budget and on schedule," Northland Power CEO John Brace confirmed.
Gemini is owned by Northland Power (60%), Siemens Financial Services (20%), Van Oord (10%) and N.V. HVC (10%).