Strata Clean Energy 2 Large Battery Projects in Sonoma and Solano

Two battery storage projects in Solano and Sonoma counties large enough to power hundreds of thousands of homes are part of a big bet California is making to store power generated by alternative sources and meet its goal of a zero-emissions energy grid.

In Vacaville, NextEra Energy Resources Development LLC plans to build the Corby Energy Storage project at the southwest corner of the Interstate 80 and Midway Road interchange at the north end of the city.

Meanwhile, Strata Clean Energy LLC plans to construct the North Bay Energy Storage project at the shuttered Adobe Creek Golf Club next to a Pacific Gas & Electric substation on the east outskirts of Petaluma.

The Business Journal recently reported on sizable battery-storage projects at the U.S. Coast Guard’s major West Coast training facility southwest of Petaluma and at Dario Sattui’s Castello di Amorosa winery in Napa Valley.

But what’s different about the Corby and North Bay storage projects is that they are part of a statewide race to shore up the power demands of the grid, rather than primarily serve the needs of a given property.

Pipeline of big batteries

The Corby project is one of nine battery energy storage system, or BESS, procurement agreements announced in late January by PG&E, whose service area is Northern and Central California, and the only one of the large batteries in the North Bay.

All nine projects would provide a total of 1,600 megawatts (1.6 gigawatts) of battery output and are intended to come online by the end of 2024.

The effort is part of the California Public Utilities Commission’s decision last June that all the state’s electrical utilities, called load-serving entities, bring on line 11.5 gigawatts of new power sources with low or no emissions of greenhouse gases between 2023 and 2026: 2 gigawatts by August 2023, 6 more gigawatts by mid-2024, 1.5 additional gigawatts by mid-2025, and the remaining 2 extra gigawatts by mid-2026.

The timing is intended to coincide with the planned retirement of Southern California natural gas plans and the 2025 decommissioning of the state’s last nuclear power plant, Diablo Canyon.

PG&E said Corby and the eight other new BESS contracts would bring its battery storage to over 3.3 gigawatts in 2024, including 600 megawatts from three storage projects turned on last year.

On a similar track, Southern California Edison last fall said is planned to reach 2.3 gigawatts of storage in 2022, plus about 5 gigawatts of demand-easing output available from private BESSes.

“California is going to be putting increasing amounts of grid reliability on very fast deployment of energy storage,”said Jason Burwen, vice president of energy storage for the American Clean Power Association, a trade group for around 640 wind, solar, storage and transmission companies. He was CEO of the Energy Storage Association until its merger at the beginning of this year.

One of the potential challenges with CPUC’s clean-grid-transition timeline in the near term, noted by the California Energy Commission in a feasibility study released last fall, is the supply chain.

But Burwen said the challenge currently is more cost than availability.

“It’s less about folks able to get batteries but the near-term bidding up of the pricing for batteries for the rapid expansion and buildout,” he told the Business Journal.

While the pricing for the PG&E and other utility battery contracts aren’t disclosed, Burwen said via government and private sources, a ballpark estimate of what these large BESSes cost can be possible, according to Burwen. The installed cost per kilowatt-hour is roughly $300-$350, varying depending on what sourcing connections the provider has and other costs such as site preparation and grid connection. So a four-hour battery could cost $1,200 per kilowatt of capacity.

Before the global supply chain challenges that have driven up the cost of many goods, pricing for battery storage had been declining precipitously, Burwen said. It declined about 90% in the 2010s, at a rate of about 5%-10% a year.

“In 2022 it will be interesting to see what the numbers are saying on whether this short-term competitiveness changes that price trajectory,” he said.

Solano project needs a zoning change

The Vacaville project would be a 125-megawatt BESS and has a target go-live time frame of June of that year, according to the utility’s news release.

A spokesperson for Florida-based NextEra Energy would only confirm that the Vacaville project was planned to go operational in 2024 and that it was in the city permitting process.

The company already contracts for net production of up to 277 megawatts of wind power from three arrays of turbines in east Solano, according to regulatory filings.

The proposed Vacaville battery site is currently zoned for housing and job-creating uses and would need a zoning change for the proposed use, according to Peyman Behvand, city planning director. A merit hearing before the City Council on such a change is tentatively set for late March or early April.

Petaluma big battery project

The North Bay Energy Storage project located at the former Adobe golf course just outside Petaluma currently is the only utility-scale BESS in the California Independent System Operator’s queue for those two counties, as storage elsewhere has been delayed, according to Sonoma Clean Power, a community choice aggregator for energy in that region.

First reported by the Argus-Courier in late 2020, the project is working toward being able to start serving the grid in mid-2024.

But that timing ultimately will be determined by the Sonoma County permitting process for the site, according to Will Mitchell, West Coast vice president of business development for Strata Clean Energy. The North Carolina-based company has been finding out what county requirements are expected before submitting a project application, he said.

Originally envisioned to supply up to 100 megawatts, a portion of which could be contracted to Sonoma Clean Power, Strata has been exploring whether electricity demand in the region calls for a bigger battery, Mitchell said.

Like most other big BESSes being installed in California, the Petaluma system is designed for a four-hour discharge at maximum output, but that doesn’t mean that’s only as long as it can operate, Mitchell said. For example, all 100 megawatts could power 100,000 homes for four hours, 50,000 for eight or 25,000 for 12.

“A battery is the Swiss Army knife of the grid,” he said.

It can operate like the mainly natural gas “peaker” plants now, varying output based on grid demand. So a BESS can ramp up discharge during an unexpected or planned outage, or when clouds or storms cut solar output. But while natural gas plants take 10 minutes to 2 hours to ramp up, BESSes can do so in the blink of an eye, Mitchell noted.

Strata turned on another utility-scale BESS in Southern California last year and has one planned among those nine PG&E projects statewide. The company also has other zero-emissions power plants across the country.

The company decided to pursue a utility battery in the North Bay because it saw a gap in the green energy mix, Mitchell said.

“It’s no secret that California is flush with solar, and solar not attached to batteries is not much value to the grid anymore,” he said. “And no gas or coal plants will be approved in the North Bay anymore.”