CMS Energy Corporation operates as an energy company primarily in Michigan. It operates through three segments: Electric Utility, Gas Utility, and Enterprises. The Electric Utility segment engages in the generation, purchase, transmission, distribution, and sale of electricity. It generates electricity through fossil-fuel-fired plants, as well as renewable energy and nuclear sources. This segment's transmission and distribution system includes 214 miles of transmission overhead lines; 188 miles of high-voltage distribution overhead lines; 4 miles of high-voltage distribution underground lines; 4,430 miles of high-voltage distribution overhead lines; 19 miles of high-voltage distribution underground lines; 56,067 miles of electric distribution overhead lines; 10,532 miles of underground distribution lines; and substations. The Gas Utility segment is involved in the purchase, transmission, storage, distribution, and sale of natural gas. This segment's gas transmission, storage, and distribution system comprises 1,670 miles of transmission lines; 15 gas storage fields; 27,920 miles of distribution mains; and 8 compressor stations. The Enterprises segment engages in the independent power production and marketing activities; and development of renewable generation. As of December 31, 2016, this segment had ownership interests in independent power plants totaling 1,177 megawatts. The company also operates an industrial bank providing unsecured consumer installment loans for financing home improvements. It serves 1.8 million electric customers and 1.8 million gas customers, including residential, commercial, and diversified industrial customers in Michigan's Lower Peninsula. CMS Energy Corporation was founded in 1987 and is headquartered in Jackson, Michigan.