Construction has begun on a 300 MW, 1,200 MWh energy storage facility in California.

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U.S. renewable energy developer and operator Arevon Energy has officially begun construction of one of the largest battery energy storage systems in the state of California.
The Nighthawk Energy Storage Project, with a capacity of 300 MW and 1,200 MWh, is being built in Poway, near San Diego. The $600 million investment is strategically important for grid stability in Southern California.

From greenfield project to full acquisition
The Nighthawk project dates back to 2020, when Arevon acquired the so-called Falcon portfolio from Tenaska. This package included nine standalone BESS projects in California. Initially, the two companies worked together to develop the investments, but in September 2023, after expanding its in-house development team, Arevon took over sole responsibility for delivering the entire portfolio.

In 2021, the company signed a long-term agreement for Nighthawk to supply energy and provide so-called resource adequacy to one of California’s largest utilities—Pacific Gas and Electric. The project will be connected to the grid through the Sycamore Canyon Substation, located at the Marine Corps Air Station Miramar.

The investment is part of a broader California Public Utilities Commission program, which requires utilities and energy suppliers in the state to procure additional capacity to strengthen supply security, especially in light of the growing share of intermittent renewable energy sources.

Technology and economic benefits
The Nighthawk facility will be equipped with Tesla Megapack systems, among the most advanced BESS solutions in the world. Arevon emphasizes that the installation will be additionally secured with enhanced safety systems, including advanced temperature monitoring, automatic section shut-offs in case of failure, and dedicated fire prevention protocols.

The project is expected to generate more than $30 million in revenue for local government budgets over its lifetime, with the city of Poway receiving about $12 million. The construction, carried out by California-based Rosendin, will create more than 130 jobs at peak activity.

Arevon has also announced that, in addition to tax benefits, it will establish a $2 million community fund to support local initiatives, including the Rancho Family YMCA, membership in the Poway Chamber of Commerce, and other efforts to strengthen ties with the local community.

As the company’s CEO, Kevin Smith, emphasized, building relationships with residents from day one is crucial:

“In every project, we know that at some point there will be a challenging moment when we will need the support of local leaders. If we haven’t engaged in the life of the community beforehand, it will be too late.”

Experience from other projects — the Peregrine model
Nighthawk is not the only large energy storage facility recently developed by Arevon. A few weeks ago, the company commissioned the Peregrine BESS project in San Diego (200 MW/400 MWh), whose financing was closed in February 2025. At the opening ceremony, attended by San Diego Mayor Todd Gloria, the company highlighted its involvement in community projects, including:

  • support for housing programs for the homeless,
  • STEM education,
  • local charity events.

In July 2025, Arevon also secured $600 million in loans to develop its portfolio of U.S. solar PV plants and energy storage systems. The company currently has one of the largest BESS portfolios in the country, with a strategy focused on combining large-scale energy storage with solar farms to ensure grid flexibility and minimize energy losses during peak solar production hours.

Arevon operates across the United States, developing projects in Arizona, Nevada, Texas, and Virginia. The company is also one of the pioneers in co-locating energy storage systems with solar power plants.

Source: solarquarter.com

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