Houston-based Plus Power announced it has begun operating a new facility on Oahu, Hawaii.

The Kapolei Energy Storage, or KES, facility is “the most advanced grid-scale battery energy storage system in the world,” which will help transition the state's electric power from coal and oil to solar and wind, according to the company.

The KES battery project is located on 8 acres of industrial land on the southwest side of Oahu near Honolulu, and will use 158 Tesla Megapack 2 XL lithium iron phosphate batteries. It will offer the grid 185 megawatts of total power capacity and 565 megawatt-hours of electricity. This will act as an electrical "shock absorber" that will be served by combustion-powered peaker plants to respond in 250 milliseconds according to Power Plus.

"This is a landmark milestone in the transition to clean energy," Brandon Keefe, Plus Power's executive chairman, says in a news release. "It's the first time a battery has been used by a major utility to balance the grid: providing fast frequency response, synthetic inertia, and black start. This project is a postcard from the future — batteries will soon be providing these services, at scale, on the mainland."

The KES plant interconnects three of Hawaiian Electric's critical power generation facilities, which can enable KES to support the reboot of power plants in the event of a state-wide emergency.The KES batteries will help replace the grid capacity formerly provided by an AES coal power plant.

By June 2024, Plus Power aims to operate seven large-scale battery energy storage plants across Arizona and Texas. Last year, the company secured $1.8 billion in new financing for a handful of ongoing projects — most of which are in Texas.