Duke Energy Corporation, together with its subsidiaries, operates as an energy company in the United States and Latin America. It operates through three segments: Regulated Utilities, International Energy, and Commercial Power. The Regulated Utilities segment generates, transmits, distributes, and sells electricity in the Carolinas, Florida, Ohio, Kentucky, and Indiana; and transports and sells natural gas in southwestern Ohio and northern Kentucky. This segment owns approximately 50,000 megawatts of generation capacity; and uses coal, hydroelectric, natural gas, oil, and nuclear fuel to generate electricity. It serves approximately 7.3 million retail electric customers in 6 states in the Southeast and Midwest regions of the United States with a service area covering approximately 95,000 square miles; and approximately 500,000 retail natural gas customers in southwestern Ohio and northern Kentucky. This segment is also involved in the wholesale of electricity to incorporated municipalities, electric cooperative utilities, and other load-serving entities. The International Energy segment operates and manages power generation facilities; and markets and sells electric power, natural gas, and natural gas liquids. This segment serves retail distributors, electric utilities, independent power producers, marketers, and industrial and commercial companies. The Commercial Power segment builds, develops, and operates wind and solar renewable generation and energy transmission projects, as well as high voltage power projects. The company was formerly known as Duke Energy Holding Corp. and changed its name to Duke Energy Corporation in April 2005. Duke Energy Corporation was incorporated in 2005 and is headquartered in Charlotte, North Carolina.