Redwood Coast Airport Microgrid
Our microgrid is done and it’s time to celebrate this major community milestone!
Join us Wednesday, June 22 at 10:30 AM to hear from project partners, community leaders, and key stakeholders.
At noon we’ll be leading a tour. Reservations are required due to limited space, so please RSVP below.
Redwood Coast Energy Authority partnered with the Schatz Energy Research Center (SERC) at Humboldt State University, PG&E, and the County of Humboldt to build a 7-acre, 2.3 MW solar array and battery energy storage system at the California Redwood Coast – Humboldt County Airport (ACV).
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 microgrid includes:
- 250 kW net metered system to offset daily electricity usage at the airport
- 2.3 MW of wholesale power that will feed clean energy directly into the grid
- 2 MW battery storage system providing 8 MWh of energy storage
- 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
- It’s a blueprint for microgrids around the state and around the country
- Electric vehicle charging stations capable of demand response
- Community Choice Energy dollars invested locally instead of exporting to distant shareholders
- Funded by a $5 million grant from the California Energy Commission’s EPIC Program, a loan from the USDA, and $6 million in match funding from RCEA’s CCE Program
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 Pacific Gas & Electric’s area of service.
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.
- 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.
- 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.
- 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.
As SERC stated in their February 2018 press release, “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 Center, and will be the largest in the county. The other three are:
- The Blue Lake Rancheria’s main campus. It went live in 2017 and supports their site’s critical role in the community as a Red Cross Shelter facility.
- The Blue Lake Rancheria’s gas station and convenience store. This microgrid will be fully operational in summer 2019.
- Humboldt Transit Authority headquarters. This microgrid is in the design phase, and HTA is currently seeking funding for implementation.
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 will be: 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. PG&E will be able to test policies, tariff structures, and operating procedures for the microgrid and battery interconnection, which should help streamline future projects in the utility’s service area.
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
- The EnergyTech Mission Critical Microgrid Series Part 1: The Redwood Coast Airport and Coast Guard Microgrid, May 2, 2022
- Schatz Energy Research Center:2
- September 2020 webinar: Redwood Coast Airport Microgrid: Advancing a resilient and clean energy future– Clean Coalition hosted a webinar with presenters Carmen Henrikson from TRC, Matthew Marshall from RCEA, and Jim Zoellick at the Schatz Center.
- Lost Coast Outpost
- California Energy Commission Okays $10M for College and Airport Microgrids
- ACV Microgrid CEQA Initial Study (PDF)