Energy company Centrica has paid £42 million cash for a 50% share of Airtricity's Braes of Doune wind farm in Stirlingshire, which began operation earlier this year. Under an earlier offtake agreement, Centrica's retail subsidiary British Gas has contracted for the entire output from the 72 MW project. This helps it meet its renewables obligation (RO), which requires electricity retailers to source a proportion of their power from renewables. The RO for Britain currently stands at 7.9% and will rise to 15.4% in 2015/16. The acquisition of the 36 turbine Braes of Doune facility brings Centrica's operating wind interests to 188 MW. It also has 180 MW of offshore plant under construction, with development licences for a further 1 GW of offshore capacity.