DTE Energy Company, together with its subsidiaries, operates as an electric and natural gas utility company in Michigan. It also involves in non-utility operations. The companys Energy Utility segment engages in the generation, purchase, distribution, and sale of electricity in southeastern Michigan. It generates electricity from various fuels, including coal, as well as from nuclear and hydro facilitates. As of December 31, 2009, this segment owned and operated approximately 677 distribution substations and approximately 423,600 line transformers; and supplied electricity to 2.1 million residential, commercial, and industrial customers in southeastern Michigan. The companys Gas Utility segment engages in the purchase, storage, transmission, distribution, and sale of natural gas in Michigan. As of December 31, 2009, this segments distribution system included approximately 19,000 miles of distribution mains, 1,177,000 service lines, and 1,312,000 active meters. It also owned approximately 2,100 miles of transmission lines that deliver natural gas; and supplied natural gas to approximately 1.2 million residential, commercial, and industrial customers throughout Michigan, as well as to approximately 17,000 customers in Adrian, Michigan. The companys non-utility operations include natural gas pipelines and storage; unconventional gas exploration, development, and production; power and industrial projects, and coal transportation and marketing; and energy marketing and trading operations. Its customers include electric utilities, merchant power producers, integrated steel mills, and industrial companies. DTE Energy Company was founded in 1995 and is based in Detroit, Michigan.