The project, located 85 miles of the Dutch coast, is being developed by Typhoon Offshore. Northland owns a 55% share of the project.
According to Northland, Construction of Gemini is expected to start in late 2014 with the aim of coming online in 2017.
The project's total cost is expected to be $3.8 billion. It will be financed with a combination of non-recourse project debt, mezzanine financing and equity from the consortium.
Gemini will add significant capacity to the Netherlands' offshore wind sector, which includes the Princes Amalia project.
In October 2012, the European Investment Bank (EIB) is considering a €500m loan to help finance the €2.6bn project, which has been redesigned and will now be powered by Siemens 4MW turbines.
Typhoon bought the fully consented project, then known as Bard-Nederland, from troubled Bard Group last year, in association with Dutch utility HVC, which holds a 15% share.
Gemini is divided into two 300MW tranches lying 85km off the Dutch coast in water depths of up to 36m, with wind speeds averaging 10m/s.
In 2010, the Dutch government granted both plots support under its renewables incentives programme (SDE), up to a maximum of €4.4bn. The SDE ensures producers a fixed price per kilowatt hour over a 15-year term.