Merger of Progress Energy and Duke Energy created largest U.S. electric utility

The July 2, 2012 merger of Duke Energy and Progress Energy created the largest electric utility in the United States (measured by number of customers). Now called the Duke Energy Corporation (Duke), the new company has over 7 million retail customers spanning six states. It also owns about 67 gigawatts of generating capacity across the eastern United States. This merger follows the recent merger between Constellation and Exelon, which created the third largest utility in the United States.

Although the Federal Energy Regulatory Commission (FERC) approved the merger, it cited concerns about the new company's potential market power in North Carolina and South Carolina. Duke and Progress addressed this concern by agreeing to build new transmission facilities through the region. As a result of these transmission additions, generators will have greater access to Duke's new electric system footprint.