This company turns the lights on in South Carolina. South Carolina Public Service Authority, known as Santee Cooper (after two interconnected river systems), provides wholesale electricity to 20 cooperatives and two municipalities that serve more than 2 million customers in South Carolina. It directly retails electricity to more than 174,000 customers. One of the largest US state-owned utilities, Santee Cooper operates in all 46 counties in South Carolina and has stakes in power plants (fossil-fueled, nuclear, hydro, and renewable) that give it more than 5,180 MW of generating capacity. Its Santee Cooper Regional Water System also distributes water to customers in its service area.