Pacific Gas and Electric Co. (PG&E) on Tuesday introduced a program to help Northern California communities develop permanent, multi-customer microgrids to ensure off-the-grid electricity to critical facilities and vulnerable customer groups.

The first installation is set for the Yurok Tribe of Native Americans. The Community Microgrid Enablement Program (CMEP) would provide technical support and capital for an electric system that can operate independently from the central energy grid for Yurok’s Tulley Creek community on the upper half of its reservation near the California-Oregon border.

Yurok Tribe planning director Michael Gerace called the microgrid “a key piece of infrastructure that will dramatically increase the energy resilience and disaster preparedness of the Yurok Tribe.”

In addition to high-risk wildfire areas that have turned to temporary microgrids in recent years,  the state regulator-approved CMEP program would support communities on a prioritized basis for qualifying projects in areas “with the greatest energy resilience needs,” according to PG&E. These include various disadvantaged and vulnerable communities.

CMEP would concentrate on permanent microgrids, but PG&E also plans to continue assisting with the installation of temporary and remote power systems.

“Standalone power systems are a new utility service concept that PG&E is developing using decentralized energy sources for permanent energy supply to remote customers as an alternative to energy supply through hardened traditional utility infrastructure,” said PG&E spokesperson James Noonan.

Noonan said there is a growing interest in multi-customer microgrids, and CMEP was created to meet the demand. “We’re working with interested communities to explore ways in which these microgrid arrangements can work in concert with the broader system, and to identify and build multi-customer microgrids serving critical local needs.”

PG&E defines a community microgrid as a group of customers and distributed energy resources, such as solar generation and battery energy storage systems, operating within clearly defined electrical boundaries and having the ability to disconnect from and reconnect to the grid.

As part of this year’s wildfire mitigation plans, PG&E is targeting 20 operational remote grid sites by the end of 2022 with sites in high fire risk areas in seven counties that are currently being assessed. PG&E aims to have its first remote grid system operational this year, Noonan said.

The project is currently under construction in Briceburg in Mariposa County, where five customer meters lost power in the 2019 Briceburg Fire. The historical line route is challenging to rebuild through the last 1.3 miles of rugged, high-fire-risk terrain, so the utility is deploying a “hybrid renewable standalone system,” according to Noonan.

“Ultimately, this (and other) initial projects will enable PG&E to determine an appropriate expansion of remote grid systems using SPSs,” he said.

Throughout PG&E’s service area, Noonan said there are pockets of isolated small customer loads that are currently served via long electric distribution lines, frequently traversing high fire risk areas. “If these long distribution lines were removed and the customers served from a local and decentralized energy source, the resulting reduction in overhead lines could reduce fire ignition risk as an alternative to, or in conjunction with, system hardening.”

In the past two years, PG&E applied temporary generation-based microgrids in areas most likely to experience public service power shutoff (PSPS) events. Temporary generation at substations and other generation sites along the distribution system allows the utility to provide electricity to serve safe-to-energize customers and key community resources when the transmission source serving them is de-energized during a PSPS event.

“In 2020, temporary generation, plus an expanded network of enhanced weather technology, along with the installation of sectionalizing devices that isolate the grid into smaller segments, enabled PG&E to keep the lights on for hundreds of thousands of customers, cutting the size of the PSPSs in half,” Noonan said.