Maine's wind industry has grown to become a $1 billion market and the biggest supplier of wind-generated power in New England, supporters said. However, the industry's growth could be undermined by the uncertainty regarding the federal renewable-energy Production Tax Credit and efforts by Gov. Paul LePage to rethink the state's wind power rules, including the so-called "expedited permitting" process. "It's not that we are going to change it. But after five years of experience, it is time to take another look at that," said Ken Fletcher, director of the governor's Office of Energy Independence and Security.