Tesla has signed a long-term power purchase agreement to acquire 90 percent of the output from Project Sterling, a 509 MW solar and 360 MW battery facility under development in Arizona.
The project is being developed by ContourGlobal, a power producer owned by private equity firm KKR. It pairs 509 MW of solar generation with a 360 MW four-hour battery storage system totaling 1,440 MWh. The facility is scheduled to come online in 2028 and will connect to the Western Area Power Administration grid.
This marks the first agreement between Tesla and ContourGlobal. ContourGlobal acquired the project in late 2024 and will retain and trade the remaining 10 percent of output. Financial terms were not disclosed.
The Arizona deal is the second large solar PPA Tesla completed on the same day. Earlier, the company secured the full output of a 140 MW solar farm in Texas from developer Zelestra, bringing its total contracted capacity that day to more than 640 MW of solar plus 360 MW of battery storage.