PG&E Corporation, through its subsidiary, Pacific Gas and Electric Company, transmits, delivers, and sells electricity and natural gas to residential, commercial, industrial, and agricultural customers primarily in northern and central California. The company’s electricity distribution network consists of 141,700 circuit miles of electric distribution lines, 55 transmission switching substations, and 603 distribution substations; and electricity transmission network comprises 18,100 circuit miles of interconnected transmission lines and 91 electric transmission substations. Its natural gas system consists of approximately 42,700 miles of distribution pipelines, approximately 6,400 miles of backbone and local transmission pipelines, and various storage facilities. The company operates generation facilities with energy sources, such as nuclear, hydroelectric, fossil fuel-fired, and photovoltaic. As of February 10, 2015, it served approximately 16 million customers. The company was founded in 1905 and is headquartered in San Francisco, California.