Redwood Coast Airport Microgrid

Redwood Coast Airport Microgrid

On June 22, 2022, local and state leaders, organizations, partners, and the public came together to commemorate the successful commercial operation of an extraordinarily collaborative and innovative project in Humboldt County – California’s first 100% renewable energy, front-of-the-meter, multi-customer microgrid. The microgrid provides energy resilience for the regional airport and U.S. Coast Guard Air Station and electricity to the Redwood Coast Energy Authority’s customers.

Leaders from various involved agencies lined up to cut a blue ribbon with some very large scissors.
Representatives lined up to cut the ribbon at the end of our Grand Opening ceremony on June 22. Congratulations and thank you to everyone who made this milestone a reality!
map of area around the RCAM

The Redwood Coast Airport Microgrid is a locally-owned, renewable energy facility at our regional airport. It serves as a modern cornerstone for a healthier, more resilient, and energy-independent community. It’s possible because our Community Choice Energy (CCE) customers support RCEA’s mission to invest our energy dollars locally rather than exporting them to distant shareholders. As each passing season demonstrates what we can expect from climate change, Humboldt shows how to be part of the solution and grow stronger in the process.

The County is leasing the land to RCEA for the airport microgrid, RCEA owns and operates the solar photovoltaic and battery systems, PG&E operates the microgrid circuit, and the Schatz Energy Research Center at Cal Poly Humboldt was the primary contractor responsible for the project design and technology integration. The RCAM project demonstrated how RCEA, as Humboldt County’s local Community Choice Aggregator, could collaborate and leverage local funding with state funding to solve regional challenges.

As we transition away from our dependence on fossil fuels it is critical that we do it in a way that doesn’t compromise our energy security and reliability; this project is a cutting-edge example of how community-driven renewable energy solutions can actually enhance energy resilience and emergency-response capabilities in addition to providing environmental and local economic benefits.

The microgrid includes:

  • 250 kW net metered system to offset daily electricity usage at the airport
  • 2.3 megawatt solar photovoltaic array feeds wholesale electricity directly into the grid
  • 2 MW battery storage system providing 9 MWh of energy, comprised of three Tesla Megapacks
  • 7 acres of land leased from the County of Humboldt
  • Microgrid controller provides the ability to “island” from the main grid so the airport and adjacent Coast Guard facility can run fully on solar and batteries if there is a regional power outage
  • Electric vehicle charging stations capable of demand response
  • Community Choice Energy dollars invested locally instead of exporting to distant shareholders
  • A $5 million grant from the California Energy Commission’s California’s Electric Program Investment Charge (EPIC Program), a statewide program which invests in scientific and technological research to accelerate the transformation of the electricity sector to meet the state’s energy and climate goals
  • Funding via RCEA’s CCE Program, thanks to a $6 million loan from the USDA 

The Redwood Coast Airport Microgrid is teaching an old electric grid some new tricks. Historically designed around centralized power generation, traditional transmission and distribution grids need to adapt to a distributed energy model. RCAM successfully demonstrates how to incorporate local renewable generation onto the existing grid and simultaneously deliver disaster resilience. In an era of aging infrastructure, electric grid resiliency is a priority for many communities, and as extreme weather events further heighten energy insecurity, our hope is to see others adopt and expand on this technology.

The microgrid will provide enough solar-generated electricity to power 430 households and prevent the emission of ~880 metric tons of carbon dioxide annually.  This system is the first multi-customer, front-of-the-meter microgrid in our region.

RCEA's photo of the microgrid with the batteries and airport in the backgroun

How does the microgrid function?

On a typical day, the energy generated from by the net metered portion of the PV array is fed directly to the airport and other electric meters to offset their electricity usage. The larger portion of the PV array will generate energy to store in the batteries and deliver power to California’s wholesale energy market. The energy provided to the wholesale market serves either RCEA customer load or provides critical ancillary services to the California Independent System Operator (CAISO), but regardless is timed based on when the grid needs it most. By storing power in the batteries, the microgrid is able to provide clean energy when demand is highest after the sun has set.

A certain amount of energy in the batteries is reserved from the wholesale market at all times to maintain the reliability function of the microgrid in the case of a local outage or shutoff. During these events, the microgrid should be able to power the critical functions of the airport and adjacent Coast Guard Air Station indefinitely. This will permit flights and rescue operations to continue across the county, even when the highways are closed.

Why a microgrid at the airport?

Although the ACV airport is known for being particularly foggy, it is actually a logical place for the planned solar array for a number of reasons.

  1. Available land: Airports have available land that cannot be developed for other uses, but can be used for solar energy generation. Many other airports have chosen to place solar panels on their property, including the Sacramento, Denver, and Pittsburgh airports. Solar panels are designed to absorb light, and the array will be properly positioned and treated with a special coating to minimize glare and ensure pilot safety, in compliance with Federal Aviation Administration requirements.
  2. Decent solar insolation: Despite its gloomy reputation, the ACV site has higher annual sun exposure than anywhere in Germany, where solar is widely and successfully used.
  3. Resiliency benefits: The airport and adjacent U.S. Coast Guard Station provide critical emergency functions that can be maintained by the microgrid during a power outage or grid shutoff.

Enhanced energy resiliency and emergency response

RCEA is dedicated to supporting locally produced, sustainable electricity projects that contribute to energy stability in Humboldt County. Our rural location on the beautiful redwood coast is one of our community’s iconic qualities, but it also makes us more vulnerable to power outages and isolation from the state’s electrical grid. This microgrid project will help stabilize power fluctuations during normal operation and provide a local power source for emergency response activities in the event that extreme weather, fires, or earthquakes should cause a regional outage.

The advent of large-scale solar on the grid has created a widespread problem of over-generation at midday, followed by the challenge of needing to ramp up non-solar generation quickly each evening as the sun sets and household loads increase. Pairing the microgrid’s battery storage with the solar generator helps address this regional problem, provides increased functionality for the microgrid, and helps minimize long-term costs of the project for RCEA ratepayers.

The Coast Guard Air Station Humboldt Bay provides search and rescue for 250 miles of rugged rural coastline, from the Mendocino-Sonoma County line to the California-Oregon border. Since roads into and out of Humboldt County are often closed by fires and slides, energy stability at the regional airport is crucial.

This is one of four microgrids designed by the Schatz Energy Research Center, and is the largest in the county. For information on the other three, please visit their microgrid page.

Opportunity for PG&E to integrate new technology into the grid

The Airport project will be the first multi-customer microgrid in PG&E’s service territory. As regulators, PG&E and other utilities plan for a flexible grid to meet California’s changing energy needs, the ability to smoothly integrate renewable energy and microgrid technology will become increasingly important. Some of the new technologies included in the microgrid are: utility-scale direct current (DC) coupling of the battery and solar arrays, which buffers the grid from large swings in solar output and makes the solar power 100% dispatchable; an automated control system linked to the battery storage system that will discharge stored solar energy during the evening peak when solar output is typically dropping off; and remote monitoring and control of the microgrid circuit by PG&E from their distribution control center.

Our  “Take Off Event” in 2021

RCEA, our partners, and collaborators gathered to share progress on July 7,  2021 at the project site.

The one-hour speaker event was live streamed on RCEA’s Facebook page.

Full coverage of the event and the project can be found on our news page, including a summary video on You Tube.

For a copy of the Notice of Availability and Draft Environmental Assessment, visit the Humboldt County webpage, under Project Documents in the menu on the right.

Articles and Press Releases

RCEA staff standing in rows in front of logo banners by the RCAM prject
Some of the RCEA staff at the RCAM celebration
Local leaders standing in front of a solar array at the Redwood Coast Airport Microgrid
Local leaders visit the Redwood Coast Airport Microgrid

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