Before Arne Jacobson began leading an effort to plan nested microgrids serving three tribal communities in Northern California, the director of the Schatz Energy Research Center understood very well the economic, social and environmental benefits of microgrids in outage-plagued regions.
Schatz had served as the technical lead for the behind-the-meter Blue Lake Rancheria microgrid, which is located on tribal land and has become a poster child for the benefits microgrids can bring to communities.
The Blue Lake Rancheria model of inviting in community
In December 2022, an earthquake struck the Humboldt County region and knocked out power. Blue Lake Rancheria, which had installed its microgrid in 2016, became “an island of electrical activity,” said Jacobson. It provided critical – and potentially lifesaving – support for local residents.
When the earthquake struck, Blue Lake reserved the ground floor of its hotel for people who needed to charge medical devices such as oxygen machines and insulin pumps. Community members lined up to get gas at Blue Lake’s gas station, purchase ice and use the available Wi-Fi.
In fact, Blue Lake’s decision to open its doors during emergencies to people who needed to charge medial devices has been credited with saving four lives during outages, said Heidi Moore-Guynup, director of tribal and government affairs for Blue Lake Rancheria.
Blue Lake, a designated emergency management refuge site, has agreements with the county and the Coast Guard allowing the agencies to create command centers on its property, and it often serves as the staging area for wildland firefighting, said Moore-Guynup.
Earthquake response inspires action
After the earthquake, Jacobson saw the opportunity to deploy microgrids in other outage-prone areas to provide similar benefits. He also identified the possibility of taking the idea one step further to create three “nested” microgrids. Still rare, nested microgrids connect several separate distributed energy resources or microgrids that are on the same utility circuit. Some view these advanced connections as the future direction of the electric grid because they can improve electric reliability. In fact, some see an eventual grid of connected microgrids.
“The earthquake motivated us and others around this idea of microgrids being so critical during emergencies,” said Jacobson.
As part of the Tribal Energy Resilience and Sovereignty project (TERAS) that recently received $87.6 million in funding from the Department of Energy (DOE), Schatz, Blue Lake Rancheria, Pacific Gas & Electric (PG&E) and the Karuk, Yurok and Hoopa Valley tribes have partnered to create three nested, front-of-the-meter community microgrids that will provide resilience to the three tribes located along the meandering 142-mile Hoopa 1101 distribution circuit owned by PG&E. This will include a microgrid located at the Hoopa Valley substation and two others that span a 26-mile route directly from the substation to the third microgrid.
Putting nested microgrids to the test at Blue Lake Rancheria
The first phase of the four-year project will test nested microgrids at Blue Lake Rancheria by adding two microgrids to two existing microgrids at the rancheria.
Blue Lake Rancheria is now building a 16,000-foot resilience campus that can serve community members during emergencies, along with a new health care facility.
“Ours will serve as a proving ground for the nested microgrid technology and then the technology will be replicated,” Moore-Guynup said.
The first phase of the project will test the logic of the nested microgrid control concept in a smaller, more controlled setting. Schatz will create the control system.
Tribes experience 100 hours of outages each year
In the next phase, the project will address the many challenges sparked by frequent outages along the Hoopa 1101 distribution circuit. The Hoopa Valley, Karuk and Yurok tribes live along the circuit, one of the most unreliable PG&E circuits, said Moore-Guynup.
The 2,200 customers living along the circuit experience over 100 hours of blackout annually, and there’s no capacity for new energy resources, said Eileen Verbeck, interim executive director at Redwood Coast Energy Authority, which was the lead applicant for the DOE funding and will play an administrative role in the project.
“These [blackouts] occur during winter storms, heat waves and smoke events; lack of electricity to help cope with those events exacerbates the impact. TERAS microgrids will integrate over 20 megawatts of clean energy (renewable generation and batteries) in a configuration that supports resilience and full electrification,” said Verbeck.
The region also experiences outages from a PG&E program that utilizes fast-trip circuit breakers to quickly take circuits offline if vegetation falls on a line, which creates a fire hazard, said Jacobson. While this program helps reduce fires, it also spurs more outages. In this case, the lines aren’t reconnected unless they have been inspected, which can take eight to 24 hours.
How outages threaten tribes’ traditional way of life
These different types of outages undermine the tribes’ efforts to continue their traditional way of life, said Moore-Guynup.
Traditional cultural practices include hunting and gathering, but tribal members often lose all the food they hunt and gather because outages knock out refrigerators. The three tribes are often without power for weeks, she said.
To address the challenges associated with unreliable power, a circuitwide advanced distribution management system will be installed along with the three community microgrids across the Hoopa 1101 circuit, said Verbeck.
“TERAS will fill a long-standing infrastructure gap in our region, building microgrids that serve 2,200 customers with 24/7/365 reliability, integrating over 20 MW of new renewable energy capacity,” she said.
“The idea is to back up as much of that circuit as you can with microgrids that can work together or in isolation,” Jacobson said.
Microgrids less expensive than hardening utility infrastructure
The project will cost about $200 million – a figure that includes workforce development – compared to a cost as high as $1 billion to underground and harden the circuit through conventional means, said Verbeck.
All of the community microgrids will be owned and operated by tribal nations. The “core zone” of each microgrid will power critical facilities and nearby households. The extended zones offer service beyond the core when it is possible to deliver energy and maintain core resilience, she said.
In addition, the grid-connected microgrids will be able to support the grid by selling energy and grid services, said Jacobson.
One of the biggest challenges will be deploying the controls that operate the nested microgrids.
Control system is key
“Essentially creating a control system that can respond quickly and handle transitions between being grid connected and not grid connected along with doing that in conjunction with a set of other microgrids that are nested is complicated and challenging,” said Jacobson. Fast communication between microgrids is key. “The fiber connections between them are critical,” he said.
The three front-of-the-meter microgrids are expected to receive incentives through PG&E’s Community Microgrid Enablement Program (CMEP), which has been criticized for failing to help develop community microgrids without subsidies.
“The funds can cover the cost of items such as any needed grid upgrades and personnel time for technical support from PG&E staff associated with microgrid design, development and deployment. Support through CMEP is a key element of the matching fund portfolio associated with the proposed project,” said Jacobson.
If successful, the effort to deploy nested microgrids could give the relatively rare idea a boost that could benefit numerous other outage-plagued communities.
“These innovative microgrids will provide reliable, renewable power to entire communities and provide a template for other rural regions,” said Verbeck.
