NRG Energy Inc., a subsidiary of NRG Solar, announced Unit 1 at the Ivanpah solar power facility in the Mojave Desert was connected to the electric power grid for the first time.
NRG said Tuesday the connection was a "major milestone" for a project situated on 3,500 acres of public land in the California desert.
Solar power generated from the Ivanpah solar facility is enough to meet the energy needs of more than 140,000 households. Nearly 400,000 tons of carbon emissions will be removed from the atmosphere each year with the project, the company added.
The project uses solar arrays that track the sun's movement and focuses its energy on steam generation.
NRG started construction of the project in 2010. The company said all three units could double the amount of commercial solar thermal energy operating currently in the United States.
Electricity from Unit 1 is sold to California utility company Pacific Gas & Electric under a 20-year purchase agreement.