NRG announced it "threw the switch" at its Avra Valley photovoltaic facility near Tucson. Power from the facility will be sold to utility company Tucson Electric Power under a 20-year purchase agreement.
"Although NRG has many distributed solar projects and thermal operations in Arizona, this project represents our first delivery of solar power to Tucson Electric Power, helping TEP meet Arizona's renewable energy goals," Randy Hickok, senior vice president of NRG's solar division, said in a statement.
NRG said the facility could meet the annual energy needs for at least 5,000 homes and avoid emissions equivalent to taking more than 10,700 cars off the road.
The company also announced it plans to merge with electricity company GenOn to create what it said will be the "nation's largest competitive generator of electricity, with about 47,000 megawatts of generating capacity."