The Electric Reliability Council of Texas (ERCOT) is an American organization that operates Texass electrical grid, the Texas Interconnection, which supplies power to more than 25 million Texas customers and represents 90 percent of the states electric load. ERCOT is a membership-based 501(c)(4) nonprofit corporation, governed by a board of directors and subject to oversight by the Public Utility Commission of Texas and the Texas Legislature. Its members include consumers, cooperatives, generators, power marketers, retail electric providers, investor-owned electric utilities, transmission and distribution providers, and municipally owned electric utilities. ERCOT manages the flow of Texas power supply, including power load, power generation units, and miles of transmission lines managed and monitored. ERCOT has four primary responsibilities: maintaining system reliability, facilitating a competitive wholesale market, facilitating a competitive retail market, and ensuring open access to transmission. ERCOT schedules power on an electric grid that connects more than 52,700 miles of transmission lines and 1,100 generation units, including Private Use Networks. It also performs financial settlement for the competitive wholesale bulk-power market and administers retail switching for 8 million premises in competitive choice areas. ERCOT works with the Texas Reliability Entity (TRE), one of six regional entities within the North American Electric Reliability Corporation (NERC) that coordinate to improve the reliability of the bulk power grid.