CMS Energy Corporation is an energy company operating primarily in Michigan through three segments: Electric Utility, Gas Utility, and NorthStar Clean Energy. The Electric Utility segment generates, purchases, distributes, and sells electricity from coal, wind, gas, renewable energy, oil, and nuclear sources, and its distribution system includes 263 miles of high-voltage overhead lines, 4 miles of high-voltage underground lines, 4,619 miles of high-voltage overhead lines, 18 miles of high-voltage underground lines, 82,854 miles of electric distribution overhead lines, 10,027 miles of underground distribution lines, and 1,102 substations. The Gas Utility segment purchases, transmits, stores, distributes, and sells natural gas, with 2,337 miles of transmission lines, 14 gas storage fields, 28,433 miles of distribution mains, and 8 compressor stations. The NorthStar Clean Energy segment engages in independent power production and marketing, including the development and operation of renewable generation. The company serves 1.9 million electric and 1.8 million gas customers, including residential, commercial, and diversified industrial customers, and was incorporated in 1987 with headquarters in Jackson, Michigan.