BrightSource Energy’s massive solar farm in a remote corner of California delivered its first flow of power to the grid, an important step for demonstrating that the project is on the final path to become a fully operating power plant, the company said Tuesday.

BrightSource achieved what is called the “first sync” with the project,Ivanpah Solar Electric Generating System, where for the first time the steam was sent to one of its three turbines for generating electricity and synching to the grid. Ivanpah is the first commercial power plant project in the United States for BrightSource, which owns a stake in the project along with NRG Energy and Google.

The project also is one of the massive solar power projects being built in California to enable the state to meet its goal of using an increasing amount of renewable electricity. The state’s mandate requires 33% of its utilities power supplies to come from renewable sources such as solar, wind, geothermal and biomass by 2020.

The project has a 392-megawatt capacity but is set to deliver 377 megawatts to the Pacific Gas and Electric and Southern California Edison . It’s sized to deliver enough power to about 140,000 homes per year.

Ivanpah is made up of three power generation stations. The “first sync” milestone took place at Unit 1, and the same step will be done at Unit 2 and Unit 3 soon. Unit 2 and Unit 3 are scheduled to start delivering electricity to the grid by the end of the year.