The well-heeled owner of Portland-based Pacific Power is one of 13 giant companies to sign a White House climate pledge. Berkshire Hathaway Energy, of which Pacific Power is a part, is the first energy company to join American Business Act on Climate Change, which is billed as a pledge toward "a cleaner energy future." The company, which is also a part of PacifiCorp, has as part of pledge promised to: Add more than 1,000 megawatts of incremental solar and wind capacity through long-term power…