June 20, 2025: The California Energy Commission has approved fast-track plans for a 1,150MW (4,600MWh) BESS project with solar facilities in Fresno County.

The Commission said on June 12 the Darden Clean Energy Project was given the green light under the state’s accelerated permitting program and is set to become the world’s largest such development to date.

Darden will be built on 9,500 acres of land that is no longer able to support agricultural production.

Energy storage will be provided by Tesla Mega Pack 2 XL (MPXL2) batteries, together with a 1,150MW solar facility with approximately 3.1 million panels. Coupled with the BESS, the plant will be able to power 850,000 homes for four hours, according to the Commission.

The project, owned by IP Darden I, a subsidiary of Intersect Power, is expected to generate an estimated $169 million in economic benefits to the local area over the project’s lifetime, estimated at 35 years.

Construction of the Darden is set to take from 18 months to three years.

The Commission said battery storage systems are important for California’s clean energy future because they store excess energy produced during peak production periods and discharge it when demand is high or generation drops, like in the evening.

“The transition to 100% clean electricity by 2045 requires bold, utility-scale projects like Darden,” said Commission chair David Hochschild.
“This project is significant not only for its size but its cutting-edge design and safety measures.”

According to the Commission, California leads the US and trails only China globally in battery storage capacity, with more than 200 utility-scale systems and over 250,000 commercial and residential installations, totalling more than 15,700 MW state-wide.

The Darden project builds on a series of clean energy records recently set in California.

On three out of every five days last year, California’s main grid hit 100% clean energy for some portion of the day, the Commission said.

That momentum continues in 2025. So far this year, the main grid has reached 100% clean energy on 138 out of 151 days, or 91% of days through May.

In 2024, the state added 7,000MW of clean energy capacity to the grid — the largest single-year increase in state history — and added 25,000MW of capacity over the past five years.