NRG Energy, Inc. is a large American energy company, dual-headquartered in Princeton, New Jersey and Houston, Texas. It was formerly the wholesale arm of Northern States Power Company, which became Xcel Energy, but became independent in 2000. NRG Energy is involved in energy generation and retail electricity. Their portfolio includes nuclear generation, coal generation, wind generation, utility scale generation, distributed solar generation, and oil generation. NRG serves 2.9 million retail customers in Texas, Connecticut, Delaware, Illinois, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Ohio, and the District of Columbia. NRG Energy has acquired eleven other energy companies, both generation and retail, that include Reliant Energy, XOOM Energy, Green Mountain Energy, Stream Energy, Discount Power and Cirro Energy. As of 2018, they generate 23,000 MW of power from 40 power plants across the country. They incorporate a range of sales channels for retail customers, including call centers, direct sales, websites, brokers, and brick-and-mortar stores. Their wholesale generation services include plant operations, commercial operations, energy services, distributed generation services, and energy, procurement, and construction services.