Aker Horizons completes the acquisition of Mainstream Renewable Power, the renewable energy company, for 900 million euros. Add to this a development pipeline of 12.5 GW and 1.4 GW in operation and under construction.|Aker Horizons completes the acquisition of Mainstream Renewable Power, the renewable energy business, for 900 million euros. This adds up to a development pipeline of 12.5 GW and 1.4 GW in operation and under construction.