NRG Energy, Inc. is an American energy company, headquartered in 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 natural gas generation, coal generation, oil generation, nuclear generation, wind generation, utility-scale generation, and distributed solar generation. NRG serves over 7 million retail customers in 24 US states including Texas, Connecticut, Delaware, Illinois, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Ohio; the District of Columbia, and eight provinces in Canada. NRG Energy has acquired eleven other energy companies, both generation and retail, that include Reliant Energy, XOOM Energy, Green Mountain Energy, Stream Energy, GenOn 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.