Clearway switches on its first battery storage retrofit in California

Independent power producer Clearway Energy has flipped the switch on the 147 MW Rosamond Central Battery Energy Storage System (BESS) in Kern County, California. The project represents Clearway’s latest investment in its nearly 850 MW BESS portfolio in operation and construction.

Rosamond Central BESS comprises four-hour lithium-ion batteries and is located adjacent to Clearway’s 192 MW Rosamond Central solar farm, which was completed in 2020. At the time, the owner-operator applauded project partners for completing the solar project “in a year with countless headwinds.”

Now, Clearway Energy has added a big battery storage system to the PV farm to the tune of $400 million, marking its first battery retrofit project. Construction was led by Rosendin and the battery energy storage systems for the project were supplied by Wärtsilä.

Rosamond Central BESS is contracted with utility Southern California Edison (SCE) under a long-term resource adequacy (RA) agreement. Under the RA contracts, suppliers are required to ensure “enough capacity and reserves for the grid operator to maintain a balanced supply and demand across the electric system,” according to California Independent System Operator (ISO). 

 Clearway has partnered with SCE on over 1.5 GW of renewable projects, including the Alta Wind complex and the more recent Luna Valley solar project currently under construction.

Overall, San Francisco-headquartered Clearway operates around 10,400 MW of gross generating capacity in 26 states, maintaining a net ownership interest in over 6,500 MW of wind, solar, and energy storage assets, and approximately 2,500 MW of natural gas generation facilities.