Edison International, through its subsidiaries, engages in the generation, transmission, and distribution of electricity in the United States. The company generates electricity through hydroelectric, diesel/liquid petroleum gas, natural gas, nuclear, and photovoltaic sources. It supplies electricity primarily to residential, commercial, industrial, agricultural, and other customers, as well as public authorities through transmission and distribution networks. The company's transmission facilities consist of lines ranging from 33 kV to 500 kV and substations; and distribution system comprises approximately 53,000 line miles of overhead lines, 38,000 line miles of underground lines, and 800 substations located in California. It serves approximately 5 million customers. The company was founded in 1886 and is based in Rosemead, California.