Des Moines Register: MidAmerican Energy provided 88.5% of customers' annual power needs from renewable energy last year, the Iowa Utilities Board has verified. That's five percentage points higher than 2020, according to a news release from the utility. MidAmerican, owned by Warren Buffett's Berkshire Hathaway, has proposed investing $3.9 billion in additional wind, solar and other renewable energy, with a goal to meet 100% of its customers' annual power needs with low-carbon sources by 2025.