Ameren provides the power that makes much of the American Midwest run. The holding company distributes electricity to 2.4 million customers and natural gas to 900,000 customers in Missouri and Illinois through regulated utility subsidiaries Union Electric (which does business as Ameren Missouri) and Ameren Ilinois. Ameren has a generating capacity of about 10,202 MW (primarily coal-fired), most of which is controlled by Ameren Missouri). Ameren operates a nuclear power facility, two hydroelectric plants, and several coal-fired plants and natural gas-fired facilities. It also purchases green power, including wind power and solar.