PG&E unveils first 100% renewable remote power system at Pepperwood Preserve

Pacific Gas & Electric Co. and Pepperwood Preserve unveiled the state’s first fully renewable, stand-alone power system at the nonprofit group’s remote site in the Mayacamas Mountains on Monday — part of the utility’s push to eliminate last-mile distribution lines from especially fire-prone areas.

The new remote, solar-powered system is owned by PG&E and will allow the utility to remove nearly three-fourths of a mile of overhead distribution lines that cascade down a wind-swept hillside. It eliminates, as well, the associated maintenance burden and wildfire liability that power lines in mountainous areas represent.

But it also will serve as a replicable model that can be used in hundreds of other locations to reduce first risk and make for a more resilient power supply, project partners said.

It is part of PG&E’s overall system hardening efforts, developed in the wake of catastrophic wildfires caused by faulty power equipment during extreme winds. Other measures include burying power lines and strengthening power poles and overhead lines.

“When you think about fire mitigation truly in action, the new PG&E remote grid complements Pepperwood’s own initiatives in wildfire resilience,” Joe Bentley, senior vice president for electrical engineering at PG&E, said during the Monday afternoon event on the grounds of the sprawling ridgetop preserve northeast of Santa Rosa.

He praised Pepperwood as a unique hub for “climate monitoring, applied research, science and education and wildfire resilience demonstration projects,” including its extensive wildfire alert camera network.

The microgrid, funded fully by PG&E, will serve the historic Bechtel House, used for meetings and instructional gatherings, as well as providing overnight accommodations for visiting researchers, student groups, scouts and others.

It includes a canopy solar array atop a carport and related power storage in a metal container nearby that makes it immune to planned power public safety power shut-offs, or PSPSs, used by PG&E and other power companies to reduce fire risk during extreme winds.

It also leaves only one short length of low-voltage line needed to connect the house, reducing the risk posed by overhead lines near and over trees ranging down the hill.

The larger, Dwight Center for Conservation Science, which includes the preserve’s offices, classrooms and event space, was excluded from the project because its power lines already are buried, Preserve Manager Michael Gillogly said.

PG&E has now installed five remote grid systems in its Northern and Central California service area since 2021. More are planned, including ones in Madera, Shasta and Tehama counties. But opportunities exist for hundreds more, Bentley said.

Though most remote grid systems also include a backup, propane-powered generator for periods when weather blocks out the sun long enough to exhaust battery storage, Pepperwood elected to go without one, given an overall effort to reduce reliance on fossil fuels, Gillogly said.

The generator also would have required fencing that the preserve preferred to go without, he said. The building’s nonessential uses also mean it’s feasible to cancel events in a pinch, though Pepperwood and BoxPower, which designed the unit, sized the battery to provide adequate storage, he said.

PG&E made a number of improvements in the structure to reduce overall power demands and extend the remote system’s battery life, installing energy efficient heating, lighting and appliances, and insulating the ceiling and floor, Gillogly and others said.

PG&E representatives would not say what it cost, but said the utility intends to go forward with other projects, prioritizing high-fire risk areas.

Pepperwood certainly qualifies. Located off Franz Valley Road high above Santa Rosa, the 3,200-acre refuge has endured repeated wildfires over time, including the 2017 Tubbs Fire, which burned within yards of the newly installed equipment, and the Kincade Fire two years later.

Both fires were sparked by power equipment and spread by high winds. Both torched more than half the property before they were contained.

Pepperwood President and Chief Executive Officer Lisa Micheli said she was thrilled to host and showcase the system.

“When you’re thinking about climate change … this project is a classic example of a mitigation project and an adaptation project,” Micheli said. “So we’re mitigating by reducing the amount of fossil fuels we’re using on site, but then we’re also being adapting to this new climate reality and the need to have a resilient energy structure here on site.”

Angelo Campus, founder and chief executive officer of Grass Valley-based BoxPower Inc., which designed and installed the system, said his company’s mission is to provide safe, reliable, economical, simple systems that can be built inside standard shipping containers and, thus, transported to remote, rural areas.

The company is now focused on working with utilities to create systems that provide more resilient power in remote locations and reduce wildfire threat but has often found companies reluctant to sign on.

“When I’m speaking with new utilities, particularly outside of California, I tell them, ‘Hey, all you have to do is build a remote grid and cut down your power poles and take down your wires.

“They look at me like I’m crazy,” he said.

But he said he was proud of PG&E for providing a safer, cleaner, reliable, economic solution.

“I believe this is a huge milestone for remote grids,” Campus said.

You can reach Staff Writer Mary Callahan (she/her) at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.