Portland General Electric is the greenest utility in the U.S. according to the Feds. 78,000 customers used renewable energy in 2010. PGE's Elaina Medina says customers purchased renewable energy equivalent to a 250 megawatt wind farm. Medina says they hold that honor for the second year in a row. One popular program allows customers to purchase 100% renewable energy for about $11 more per month.