CMS Energy Corp. is a holding company, which engages in business through its subsidiaries. It operates through the following business segments: Electric Utility, Gas Utility, and Enterprises. The Electric Utility segment refers to the generation, purchase, transmission, distribution, and sale of electricity. The Gas Utility segment is comprised of the purchase, transmission, storage, distribution, and sale of natural gas The Enterprises segment engages primarily in domestic independent power production, marketing of independent power production, and the development of renewable generation through the various subsidiaries and certain equity investments of the company. The company was founded in 1987 and is headquartered in Jackson, MI.