Take note of the microgrid activity in Humboldt County, California, where this week officials approved plans to seek state funding for an airport microgrid.
Courtesy of Siemens
Should the project come to fruition, it will be the community’s second microgrid. The first is the much-cited Blue Lake Rancheria microgrid, now in operation.
Two microgrids might not seem like much. But with only 135,000 people, the county would have a ratio of one microgrid per 67,500 people.* That compares to a worldwide ratio of one microgrid per 4 million people, based on Navigant Research’s latest microgrid inventory.
Which begs the question: What’s up with Humboldt County and microgrids?
Located on 4,000 square miles on California’s northern coast, Humboldt County can be described as highly microgrid-worthy. It is remote, prone to natural disasters, and green leaning. But the region has something else too — a group of about 30 passionate, environmentally conscious engineers, right in its backyard.
They work at the Schatz Energy Research Center (SERC), an affiliate of Humboldt State University’s Environmental Resources Engineering program. SERC was behind the design of both the airport microgrid and the Blue Lake Rancheria project.
The microgrids emanate from the center’s stated goal of moving us from the “energy hunter-gatherers we are now to the energy farmers we must become.” From SERC’s perspective this requires making renewable energy more affordable and microgrids more replicable.
The center operates internationally, but has made a conscious effort to focus locally too, according to Peter Lehman, SERC founding director.
Perfect playground for microgrid engineers
In many ways Humboldt County is the perfect playground for engineers trying to improve upon microgrids. Lehman describes the redwood forest community as “an energy island” with only a 70-MW connection to California’s grid. Utility poles and wires traverse rough terrain, in a county that is half the size of the state of Vermont, with one-fifth of its population.
“We understand the need to be self-sufficient,” Lehman said.
Resilient power is crucial to the California Redwood Coast-Humboldt County Airport, especially during a disaster, given that the community’s road access is limited. Only two highways connect the county to the rest of the world, one restricted this week because of the fires in California, another from earlier landslides.
“We have more earthquakes than any other area of California. Floods, fires, tsunamis — a lot of things that could happen. We need to be ready. The airport is a link to the outside world,” Lehman said.
The county’s Board of Supervisors gave the project the okay earlier this week to seek $2 to $5 million in funds from the California Energy Commission, which has made $44.7 million available for microgrids. SERC will submit the grant; other partners working on the airport microgrid include the Public Works Aviation Division, the Redwood Coast Energy Authority (RCEA) and Pacific Gas & Electric (PG&E).
Airport microgrid serves two roles
The solar plus storage microgrid will be designed to provide more than one function. During an emergency it would island and supply power to the airport (served by two commercial airlines), along with a U.S Coast Guard Station, an animal shelter and other small electric accounts.
During normal operations, the project would supply power to a community choice aggregation, a state-sanctioned program that allows local governments to offer consumers cleaner energy under flat rates competitive with local utilities. The microgrid would increase the aggregation’s access to renewable energy and lower its greenhouse gas emissions.
Situated on nine acres, the airport microgrid will include two solar arrays. The smaller one will be sized for 250 kW. The capacity of the larger array has yet to be publicly specified. The project also will include an energy storage battery system and up to four electric vehicle charging stations.
Various partners will own pieces of the project. The utility, PG&E, will retain a distribution circuit, switch and related equipment. RCEA will own the larger solar array, battery and EV charging stations. The county public works department will own the smaller array.
Remote Humboldt County has limited highway access to the rest of the world[/caption]
Money savings from Blue Lake Rancheria microgrid
The energy world has already taken note of Humboldt County because of Blue Lake Rancheria. Often cited as an example of how to build and operate a low-carbon microgrid, the project is now under consideration as a finalist for two prestigious industry awards, one from S&P Global and the other Pennwell.
The project allows the tribal community to back-off use of fossil fuels and employ solar and battery assets to reduce carbon dioxide emissions by 150 tons annually.
Managed via an advanced control system by Siemens, the Blue Lake Rancheria microgrid leverages its on-site generation and grid power to keep electricity prices in check for the tribe. Blue Lake Rancheria calculates that it will save about $250,000 per year on energy, allowing it to increase tribal employment by 10 percent, according to SERC.
Blue Lake Rancheria was granted full permission to connect to the PG&E grid on July 28. The Humboldt County Airport microgrid is in early stages and its fate may rest on how well it does in the CEC grant competition. In any case, look to the faraway community — and its energy engineers — to continue to offer microgrid lessons for the wider energy world.
* Editor’s note: The microgrids do not actually each serve 67,500 people; the ratio is provided solely to illustrate the frequency of microgrids.
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