It's the Philadelphia Electric Company. They are responsible for the power for Philadelphia and its suburbs, and the natural gas for the suburbs (PGW does gas in the city). They're responsible for the faulty power transformer on my block which seems to need to explode every month or so, leading me to buy a UPS to keep my headless computers on. PECO's electricity and transport sections are now deregulated, so you can pick your power supplier if you want one that uses windmills and solar power or just want to save money.