Partners Group has invested $500 millionfor a majority stake in Budderfly, a self-described energy-as-a-service startup that's become one of the fastest-growing private companies in the U.S.
Why it matters: Energy efficiency may seem ho-hum, especially compared to flashy new technologies. But the investment from the European private equity giant is the latest signal that even traditional investors see big bucks to be made by helping companies cut energy consumption.
