Nested Microgrids Planned by Three Northern California Tribes

In what’s emerged as a center of microgrid innovation, Humboldt County, California, appears poised to produce yet another microgrid project with an interesting story to tell, this one for hunter gather tribes far from grocery stores, deeply dependent on refrigeration and plagued by unreliable electricity.

The three California tribes seek to deploy three nested microgrids that also would support emergency services, help the tribes electrify and lower emissions from fossil-fired generators.

With frequent exposure to wildfires, public safety power shutoffs, electrical pole damage and storms, the tribes experience blackouts that can last up to two weeks. They access their electricity from a single 30-mile-long distribution circuit serving Humboldt County’s rural, mountainous region in Pacific Gas and Electric (PG&E) territory.

“These outages affect our tribal community greatly and have an impact on emergency services, water infrastructure, broadband, medical devices, heating/cooling and basic communication for our most vulnerable populations,” said Linnea Jackson, general manager for the Hoopa Valley Public Utilities District, a chartered entity of the Hoopa Valley Tribe. The region experiences at least four times more outage-minutes than other areas served by PG&E, she said.

Keeping food from spoiling during these blackouts is critical to the tribes because grocery stores are a few hours’ drive away. Most tribal residents own several refrigerators and freezers to store groceries and culturally important foods. When the tribes lose power, members use fossil-fueled generators to power the refrigerators.

"This is a great opportunity for the microgrid program and the Karuk Tribe. Refrigeration is an issue during any outage, which are common here," said Shawn Bourque, environment coordinator for the Karuk Tribe's Department of Natural Resources."We are excited about the possibility of having tribal sovereignty over our power.”

Members of the three tribes – Karuk, Hoopa Valley and Yurok – have to travel hours to reach grocery stores, according to a paper, Assessing the potential and pathways for renewable energy transformations in Orleans, California, presented to the faculty of California State Polytechnic University, Humboldt, by a student, Malcolm Prescott Moncheur de Rieudotte.

The university is home to the Schatz Energy Research Center, which is helping the tribes reach their resilience goals.

Learning from other Humboldt County microgrids

Begun as a partnership between the Karuk Tribe and Schatz Energy Research Center, the project was expanded to include the other two tribes. Together the three tribes have proposed a $500 million project encompassing three front-of-the-meter microgrids, each about 1 MW. Blue Lake Rancheria, another Humboldt County tribe with a microgrid system, is lending its expertise to the project, said Peter Alstone, associate professor of engineering at California State Polytechnic University, Humboldt, and a faculty scientist at Schatz Energy Research Center.

The tribes are seeking $250 million in federal funding through the Department of Energy’s Grid Resilience and Innovation Partnership Program, and that amount would be matched by state and tribal funding sources, Alstone said. The California Energy Commission (CEC) recently submitted a request for the federal funding.

The three microgrids, consisting of solar and storage, would be networked together. The project faces a number of challenges, including deciding how to allocate power among the tribes, said Alstone.

The project is based in part on work the Schatz Energy Research Center conducted for the Redwood Coast Airport Microgrid. Both the research center and airport are in Humboldt County.

“We need to work to integrate these systems with PG&E’s distribution system,” said Alstone. “We’re thinking of different combinations of breakers opened and closed and making sure operations are reliable and safe.” Part of the challenge is addressing protection rules about reconnecting to the utility after the microgrids island from the grid, he added.

“We would work collaboratively with PG&E to put this in place,” said Alstone.

Microgrids open path to electrification

Not only is reliable power for refrigeration critical to the tribes, but they also want to decarbonize with electrification — including transportation and heating electrification.

“This connection between food, transportation and energy systems highlights the intersectional and intertwined insecurities faced by Karuk people in Orleans,” said the California State Polytechnic University paper describing the project.

Under one scenario presented in the paper, 25% to 50% of the Karuk Tribe’s transportation and water heating would be electrified. This would boost community electricity demand by 40% to 80%. A microgrid could provide up to 12 days of autonomy with solar generation, or two days from just battery power. For residents with electric vehicles and heat pumps, utility bills would drop by 10% to 19% because the technologies are more energy efficient. Communitywide emissions would drop by 22% to 44% with the microgrid.

Blue Lake Rancheria’s success

During a March 2 meeting at the CEC about advancing the use of clean energy in partnership with Native American tribes, David Hochschild, chairman of the CEC, noted that the Blue Lake Rancheria microgrid — which is located close to the other three tribes — has protected residents from about 30 outages. “But we can do so much better, and so much more,” he said, adding that the tribal microgrid program, a partnership between the CEC, the California Public Utilities Commission and the tribes, has been a “real success.”

The three participating tribes expect the microgrids to yield many long-awaited and much needed benefits.

“The Hoopa Valley Tribe is proud to be a part of this project so we can help provide regional energy resiliency, improve tribal energy sovereignty and bring resources to the table for long awaited grid improvements,” said Hoopa Valley Tribe’s Jackson.