The Redwood Coast Airport Renewable Energy Microgrid being installed at Humboldt County’s Main Airport
Redwood Coast Energy Authority is partnering with the Schatz Energy Research Center (SERC) at Humboldt State University, PG&E, and the County of Humboldt to build a 7-acre, 2.25 MW solar array and battery energy storage system at the California Redwood Coast – Humboldt County Airport (ACV).
The County will house the airport microgrid, RCEA will own and operate the solar and battery systems, PG&E will operate the microgrid circuit, and SERC will be the prime contractor responsible for the project design and technology integration.
The microgrid will include:
- 250 kW net metered system to offset daily electricity usage at the airport
- 2 MW of wholesale power that will feed clean energy directly into the grid
- 2 MW battery storage system providing 8MWh of energy storage
- Microgrid controller providing 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
- Enough solar-generated electricity to power 430 households, and prevent the emission of ~880 metric tons of carbon dioxide
This project is being funded by a $5 million grant from the California Energy Commission’s EPIC Program, with $6 million in match funding from RCEA. This system will be the first multi-customer, front-of-the-meter microgrid in Pacific Gas & Electric’s area of service. Groundbreaking will begin spring of 2020 with the system expected to be fully operational in December of 2020.
How does it work?
On a typical day, some of the energy generated from the PV arrays will be stored onsite, some will be fed directly to the airport and offset electricity costs, and some will be sold on California’s wholesale energy market. The energy sold on the wholesale market will be timed to best support renewable energy on the grid. By storing power in the batteries, the microgrid will be able to provide clean energy when demand is highest and the sun has set.
During a power outage, the microgrid’s solar + battery storage system will maintain electricity indefinitely for the airport and adjacent Coast Guard Air Station. 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 is known for being particularly foggy, it is actually a logical place for the planned solar array for a number of reasons.
- Airports have available land that cannot be developed for other uses. Many other airports have chosen to add 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.
- Despite its gloomy reputation, the ACV site has higher annual sun exposure than anywhere in Germany, where solar is widely and successfully used.
Aerial photo of the airport provided by SERC
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 a solar microgrid helps solve 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 at:
- 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 PG&E and other utilities plan for a strong 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 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.