PG&E deploys its first 100% renewable remote grid in wildfire mitigation push

Pacific Gas and Electric Company (PG&E) has commemorated its first fully renewable remote grid in the utility’s growing fleet of standalone power systems, located in Pepperwood Preserve in Sonoma County.

As described in PG&E’s Wildfire Mitigation Plan, remote grids provide utility service using standalone local energy resources. Throughout PG&E’s 70,000-square-mile (181,299.17-square-kilometre) service area, there are remote customers served via long electric distribution lines that traverse high fire-risk areas. Replacing these distribution lines with a remote grid is meant to cost-effectively meet customer needs and reduce fire ignition risk.

PG&E faced increased regulatory pressure after its equipment was found responsible for a series of wildfires in Northern California, including the 2020 fire which resulted in the deaths of four people and destroyed hundreds of houses. California’s Public Utilities Commission found that PG&E was neglectful in its maintenance of the grid.

Remote grids were just one of several countermeasures that PG&E announced it would deploy earlier this year to mitigate the risk of similar wildfires occurring in the future. Other solutions include ground-level distribution systems, automated and beyond-visual line-of-sight drone operations, backup power and cutting off power after detecting faults.

The fully renewable remote grid at Pepperwood replaces 0.7 miles (1.1km) of overhead distribution line, reducing the associated wildfire risk.

The location was identified, designed and deployed as part of PG&E’s system hardening work, which prioritises powerlines based on elevated wildfire risk and geographic considerations.

In addition to remote grids, PG&E’s system hardening efforts include undergrounding, installing stronger and more resilient poles and replacing bare powerlines with larger, covered lines.

PG&E described Pepperwood Preserve as a living laboratory for crafting climate and wildfire solutions grounded in conservation science.

The 3,200-acre property is a refuge for more than 900 species of native plants and wildlife and was directly impacted by both the Tubbs and Kincade Fires. Pepperwood is a hub for climate monitoring, applied research, science education and wildfire resilience demonstration projects, such as the now extensive ALERTWildfire camera network. The new remote grid will power Pepperwood’s Bechtel House, which houses overnight visitors.

“Pepperwood regularly hosts researchers, policy-makers and philanthropists from around the world to learn about wildfire resilience innovation. We are delighted to partner with our clean energy leaders on PG&E’s first fully renewable remote grid in California,” says Lisa Micheli, president and CEO, Pepperwood Foundation.

“As a research and education institution dedicated to showcasing best practices, we look forward to benefiting from this clean energy source and presenting it to visitors from near and far as part of a new wave of remote energy solutions.”

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Local energy resources to meet local needs

Achieving a 100% renewable remote grid at Pepperwood required a high level of collaboration between many project partners, PG&E said.

From the start, Pepperwood and Sonoma Clean Power (SCP) engaged with PG&E to vet the potential for a remote grid without any fuel-based backup generation. 

SCP performed an upfront energy audit in addition to consulting at key project milestones that helped establish how a solar-plus-storage system could be tailored to the customer needs at Pepperwood’s Bechtel House.

Under contract to PG&E, BoxPower designed, built and will maintain the remote grid at Pepperwood.

The system includes a BoxPower SolarContainer featuring a battery energy storage system that was prefabricated at the BoxPower facility in Grass Valley before being transported to the site. The generation source is a canopy solar array. Construction of the system was completed in less than eight weeks and followed by a rigorous testing and commissioning process.

Under contract to PG&E, project partner Franklin Energy installed a targeted set of energy efficiency improvements at the house that are expected to reduce the possibility of outages during periods of low solar generation.

Franklin Energy’s end-to-end scope included detailed energy modeling of the proposed efficiency improvements that in turn informed the remote grid system design. The new energy-efficient insulation, HVAC, and similar improvements have already contributed to reduced energy usage and increased comfort at the house.

“Efficiency and renewable power go hand in hand,” said Brett Bishop, Technical Advisor for Franklin Energy. “It was rewarding for our team to put this synergy into practice while showing it can improve the lived experience at the house as well.”

Expansion of remote grids in the 2020s

The remote grid at Pepperwood will be PG&E’s fifth operational remote grid since 2021.

Collectively, PG&E’s five remote grids enable 10 customers to continue receiving energy while removing approximately five miles (eight kilometres) of overhead distribution electric lines at the grid edge in high fire-threat areas.

PG&E has identified many locations where remote grids may be the most effective way of reducing wildfire risk and improving electric reliability, the utility said, with additional sites either in development or being assessed in Madera, Shasta, and Tehama counties, among others.

PG&E plans to scale its remote grid fleet to dozens of systems over the next several years, leveraging Richmond, Calif.-based New Sun Road’s Stellar Microgrid OS as the remote monitoring and control platform.

The Stellar platform enables PG&E to monitor and control remote grids via satellite and cellular connectivity, with capabilities for remote performance management, safety diagnostics, alarms, reporting, and automated refueling notifications. Remote grids also feature an integrated fire suppression system to protect the hardware and facility.

Originally published by Sean Wolfe and edited with permission from Power Grid.