The Swedish utility said the move was part of its patnering strategy in 2014 to raise SEK 50 billion (€5.4 billion) to invest in new wind energy by 2020.
"Our partnering strategy is now paying off and delivering additional funds to fulfill our ambitious growth targets within the wind area, thereby supporting Vattenfall's overall strategy to transform our production portfolio towards renewables." said Vattenfall's head of wind Gunnar Groebler.
Following a restructure, Vattenfall created a wind division in March 2015, demonstrating the company's future emphasis will be on wind.
Ormonde was commissioned in 2012 in the Irish Sea.
It is the only commercial offshore project in the UK to be powered by Senvion turbines. The 30 turbines of 5MW are installed on jacket foundations 10km from Barrow-in-Furness, northwest England.