Commonwealth Edison Company (ComEd) is a unit of Chicago-based Exelon Corporation, one of the nation’s largest electric utilities with approximately 5.2 million customers and more than $15 billion in annual revenues. ComEd provides electric service to approximately 3.7 million customers across Northern Illinois or 70 percent of the State’s population. The geographical service area of 11,525 square miles extends into 25 counties across the Northern one-fifth of the state of Illinois and includes the city of Chicago.