MidAmerican Energy, which has more wind power on its system than any single US utility, provided its Iowa customers with 50.8% of their electricity from renewable sources in 2017.
Des Moines-based MidAmerican, part of billionaire Warren Buffett’s Berkshire Hathaway conglomerate, is believed to be the first large US utility to serve more than half of its retail electric load using renewable generation.
