Iowa-based MidAmerican Energy Holdings, the US leader in wind power ownership among regulated utilities, grew even larger last month by buying financially troubled Constellation Energy Group for $4.7 billion. The Constellation deal gives MidAmerican 8.7 million utility customers from coast to coast. Two of its subsidiaries, Iowa-based MidAmerican Energy Company and Oregon-based PacifiCorp, will own, operate or hold power purchase agreements for 2501 MW of wind generation by the end of this year. "Of that, 2077 MW is in MidAmerican ownership, says the company's Sara Schillinger. "We're the largest utility owner of wind generation facilities in the country." Constellation's Aaron Koos says his company has no wind power online, but has 381 MW under contract in various states. Most significant of those are two Twin Groves projects in McLean County, Illinois, operated by Energias de Portugal subsidiary Horizon Wind Energy, which account for 297 MW. Constellation, based in Baltimore, Maryland, accepted the MidAmerican offer, which included a $1 billion cash infusion, over an offer from government-owned French energy giant EDF, also a major investor in US wind farms. MidAmerican, with more than $12 billion in annual revenue, distributes energy in the US and UK. The company was bought in 2000 by Berkshire Hathaway, owned by Warren Buffet, ranked in 2008 as the world's richest person. MidAmerican's purchase of Constellation must be signed off by shareholders and regulators before it is a done deal.