The Nordlicht II project, together with the previously announced Nordlicht I project in the same area, will amount to an output of 1.61 gigawatts, Vattenfall said.
The two wind farms could together produce enough electricity to cover the annual consumption of more than 1.7 million German households, it added.
Pending a final investment decision, the two projects could be connected to the German grid by 2027 and 2028 respectively, Vattenfall said.
The rights to the Nordlicht II project were initially awarded to competitor RWE (RWEG.DE) at an auction in August.
However, Vattenfall had previously developed a project at the site, allowing it to exercise a right of entry to develop and construct the wind farm.
Vattenfall already operates two wind farms in Germany.
Earlier this year, the company paused the development of a planned offshore wind farm in Britain after rising costs.
