KKR. a private equity firm, plans on buying a one third stake in Spain's Acciona for $417 million euros. The firm is looking to develop the world's largest renewable energy portfolio. The deal values Acciona Energia International at $2.6 billion euros. The also includes Acciona Energia's renewable assets outside of Spain, 2.3 gigawatts across 14 countries including the U.S. Italy, and South Africa.