Decatur Island Solar Project

The energy world is changing dramatically due to climate impacts, carbon reduction legislation, and the transition toward renewable power. The goal of our state and nation is to transition away from fossil fuels and heat our homes and fuel our cars, trucks and ferries using clean electricity. This lofty goal is proving to be highly challenging.

The hydropower systems that have historically supplied most of the Pacific Northwest’s electricity are at capacity, coal plants in the region are being shut down and natural gas generation comes with a carbon-based financial penalty. Our dilemma is figuring out how to satisfy increased demand for electricity while our supply of carbon-free firm power is shrinking. As more coal plants shut down and are replaced with intermittent resources (solar and wind), energy shortfalls are increasingly predicted. Given our remote location, our best bet for clean and affordable firm power is to build renewable generation projects locally.

The two submarine cables serving San Juan Islands are reaching their useful lives and are at capacity. While OPALCO can cover the current electrical demand, any load growth is going to be difficult to serve. Local generation will be essential to keep a safe and reliable grid.

OPALCO is looking at expanding its Community Solar on Decatur Island. In March 2025, OPALCO acquired 19-acres adjacent to its current property on Decatur Island. The project will expand the solar site with additional Community Solar shares that members can purchase and benefit from the solar energy. OPALCO will be able to utilize Department of Commerce grants funds to install solar that will directly benefit low-income community members throughout San Juan County.

OPALCO is not planning to overburden Decatur with solar generation needed for the rest of San Juan County. If we added up all the solar generation currently proposed for Decatur (existing, plus planned), the total kWh generation could offset Decatur’s projected increase in electric usage (>30%).

OPALCO is a non-profit cooperative, and we rely on the members to ensure we can fulfill our mission to provide reliable power to everyone in San Juan County. We abide by the 7 cooperative principles and remain committed to serving all of the membership.

Area A

• ~1.5 MW solar array
• ~6 acres
• ~2,275 MWh annual solar production
• ~1% of OPALCO’s annual load
• ~3,100 panels (580 watt panels)
• $1M of the project is funded through Department of Commerce to support low-income energy assistance programs

Area B

• ~2.5 acres
• ~1,100 panels
• 0.55 MW
• 840 MWh annual solar production

Decatur was selected due to its proximity to the existing solar site and substation. The expanded solar will meet the needs of Decatur Island’s future power supply and offers local non-carbon-based renewable energy to the community. From both a financial and environmental standpoint, expanding existing facilities is more efficient and generally less impactful than building entirely new infrastructure elsewhere. OPALCO plans to site microgrids throughout San Juan County.

This expands the local source of renewable energy and priority access to solar shares. The project is being developed on OPALCO-owned property, which allows for efficient implementation and maintenance. OPALCO is committed to transparency, environmental stewardship, and ensuring the project brings long-term value to the community. See the list of community commitments listed below.

The amount of solar being proposed for Decatur is NOT more than the expected increase (20-30% in new homes in next 10 or so years) in electricity needed for Decatur Island. Decatur is a logical location because OPALCO already has an existing solar site and substation on OPALCO-owned property. OPALCO remains committed to the cooperative principles which emphasizes fairness as a key tenet, so we are not asking Decatur to shoulder more of this burden – the potential solar OPALCO is still less than the expected load growth on Decatur. In addition, OPALCO plans to site microgrids throughout San Juan County.

Here is historic data for Decatur’s load growth:

Here is a link to the over local load forecast based on the San Juan County Comprehensive plan: https://www.opalco.com/quick-fact-local-energy-forecast/2025/07/.

OPALCO is looking to put multiple microgrids on all the major islands. OPALCO is also working with San Juan County to ensure more permitting predictability for future solar / battery projects on the other islands. OPALCO foresees all the islands needing increases in electricity (>30%).

Electricity flows to the nearest point of use. This means that the power generated by the Decatur solar array is primarily used to serve the Decatur distribution system. If there’s more electricity produced than is immediately needed, the excess flows into the broader OPALCO transmission system to support other areas – from this portion of the system power would flow to Lopez or Blakely.

Will this also be true for the proposed solar project?

Yes. The electricity generated by both the existing and proposed solar arrays on Decatur Island will still flow to the closest point of demand, primarily serving the Decatur community. Even during summer months, when solar production is highest and local electricity use is lowest, the total output from both arrays will not exceed what Decatur residents consume.

It’s important to note that OPALCO’s grid is interconnected and serves all co-op members. While we can’t guarantee that electrons from the Decatur arrays are used exclusively on Decatur Island, the nature of electrical flow means that the community will directly benefit from most of the local generation.

OPALCO is committed to serving OPALCO members with reliable power while maintaining high environmental standards throughout the life of this project. Per discussions with San Juan County, the proposed project is required to undergo a Conditional Use Permit process. This entails an administrative review of application of San Juan County Code and State Environmental Protection Act (SEPA) review. Additionally, the project will undergo a National Environmental Protection Act (NEPA) review. We have outlined the extensive environmental reports OPALCO will provide during this process on the Decatur Solar website (www.opalco.com/decatur). The Decatur community has made several requests in how this project can benefit Decatur Island. Based on that feedback OPALCO is committing to:

• Site evaluations of alternate areas on Decatur Island: https://www.opalco.com/wp-content/uploads/2025/10/Decatur-Solar-Site-Alternatives.pdf
• Landscaping around the Decatur Substation and proposed construction areas on the road front
• Removal of Derelict Vehicles – 16 vehicles total include 3 boats and appliances
• Water access for fire suppression and miscellaneous site purposes and continued use by the Decatur Fire Brigade of the structures on property.
• Removal of County Parcel Proposed Solar from Plans
• Provide environmental, permit and mitigation plans:
  • Site design
  • Critical Area and Wetland Delineation Report
  • NEPA Compliance Documentation
  • SEPA Checklist
  • Clearing and Grading Plan
  • Landscaping Plan
  • Forest Health Report
  • Stormwater Plan
  • Construction plan & timeline
  • Fire Mitigation Plan
• Cover the 30% Load Growth for Decatur Island

Per community feedback and county requirements OPALCO will be landscaping along the site of the future solar installations that are along the county road. There will also be fencing. With the new property, OPALCO will be able to stage its equipment out of view from the road. We will be continuing to improve the longstanding substation site.

OPALCO will work with San Juan County to encourage road dust mitigation during construction times. OPALCO will have plans and timelines so residents will be aware of construction impacts. The team will work to keep the timeline condensed and leverage efforts to keep construction impacts to a minimum.

About 8 acres of the site will be cleared of trees. The forest on the site has been logged several times, and many trees are still young or moderate in size. There is also a mix of fallen trees from wind damage and signs of tree root disease in some areas. The tree density is high, and the underbrush is thick which provides habitat function but also increases risk of wildfire. This is a common forest type for the islands. There are no rare plant species in the area. The remaining area will be wetland protection and wetland setback protection areas, based on the wetland delineation report. We will install code compliant landscaping barriers to make the view from the road aesthetically pleasing.

Based on the feedback we’ve gotten from concerned residents, OPALCO decided not to move forward on this portion of the project.

No. OPALCO will be following all San Juan County permitting processes.

OPALCO will share the well water with the Decatur Fire Brigade for the community purposes. OPALCO will also ensure that water will be available to newly landscaped areas for the first 3 years as plantings get established.

Construction could take 3-6 months depending on many different factors.

The timeline is a moving target but here is what we anticipate for this project:

• March 2025 – OPALCO purchases Loveless property
• April – July 2025 Preliminary Design and Permitting Studies
• July – November 2025 Finalize San Juan County Land Use Permit Process
• Late 2025 Conditional Use Hearing
• After CUP permit is granted, OPALCO Board reviews materials decides whether to move forward
• Early 2026 San Juan County Building Permit Process
• Spring 2026: Community Solar share sales begins
• Spring 2026 Construction begins
• Fall 2026: Commission project

In order to install the solar array, there will need to be tree removal. The forest on the site has been logged several times, and many trees are still young or moderate in size. There is also a mix of fallen trees from wind damage and signs of tree root disease in some areas. The tree density is high, and the underbrush is thick which provides habitat function but also increases risk of wildfire. Only one side of this project will be visible from the road. If there is lumber or chips, OPALCO will make this available to the Decatur community.

OPALCO will make the Decatur residents aware when there are downed trees or chips available for the community.

As part of the cultural resources study and assessment, phone calls, emails, and letters were sent to the Suquamish Indian Tribe, Lummi Nation, Snoqualmie Tribe, Swinomish Tribe, Samish Nation, and Tulalip Tribes. Several of the Tribes provided information to support the cultural resources assessment and were in agreement with the findings.

OPALCO will maintain fire suppression systems, share well access for fire use, and ensure best practice prevention measures are in place for the solar site. OPALCO is also researching whether the well on the property could be utilized for fire protection. There will be a fire mitigation plan published to the website as the actual project details get finalized.

This solar site has a very low probability of causing a fire. If a fire is to enter the site, the panels are rated to not contribute to a fire that can be sustained by grass and vegetation under panels. Cleaning up the forest could help mitigate wildfire spread. The high tree density and thick underbrush increase the risk of wildfire.

There are no plans for additional battery storage for this project. Battery storage is still very expensive and OPALCO relies on grant funding for these projects. If there is an opportunity for a battery storage grant OPALCO would likely apply for those funds.

Based on the equipment installed to date within the substation, there is little space to do so and these batteries can be cost prohibitive.

The current battery system is utilized to shave OPALCO’s peak.  This means we discharge the battery to reduce the energy need at a specific time of the day, normally the morning from 7-9AM.  This aids in reducing OPALCO power costs from the mainland. Additionally, it is used for outage mitigation. In the case where the Decatur substation’s transmission feed loses power, the battery will try to sustain the loads only for Decatur and Center Island. This has been successful on two instances.

Yes, it creates increased reliability and lower power costs.

The battery system installed in 2020 on Decatur uses a chemical called Lithium Iron Phosphate.  This type of battery has proven to be one of the safest battery chemistries available.  This is very different from batteries as used in modern electric vehicles.  These batteries weigh more yet have an extremely low probability of thermal runaway.  In addition, there is a fire detection and suppression system installed. In 2021, OPALCO briefed all of the fire departments that would join a site tour on the battery and its operations and emergency protocols. OPALCO also briefed WA DNR, Decatur’s official fire response agency, on the battery as well.

This varies based on the loads and time of year. In the summer it may be able to do so for up 4 hours or more yet in the winter may be 2 hours or less. This is dependent on the number of homes in use at the time, what household functions they are conducting, and heating needs.

This is a great idea, and we are researching if there is a way to make this automated.

There have been several times since 2018 that the battery has enabled Decatur Island to keep power up and running. If the outage is on the Decatur grid, then this disconnects your service from the battery and/or BPA/OPALCO substation, so the battery is unable to provide backup power for those kinds of outages. When the outage is between the mainland and Decatur then the battery can provide backup that will extend the power supply to Decatur meters. In January 2021 and December 2022 during outages, the battery extended the power supply for Decatur Island.

OPALCO does not vary rates based on if you have a microgrid close to your home. As a cooperative, we follow “cost-of-service” model when setting rates and there is no clear correlation between having a microgrid close to your house and your electricity usage. OPALCO is looking out for all the co-op membership regardless of location of our electrical infrastructure and must set rates to benefit the whole of the cooperative.

Yes. Decatur residents will have be able to purchase shares in this project.

After four years of working on permitting this project, it was determined by San Juan County that additional requirements were needed for the project that had not been previously identified. OPALCO has paused this project until those requirements can be met and then will re-start the process to get this project up and running. OPALCO still owns the land and plans to install an agri-solar project at this location.

OPALCO will continue finalizing the conditional use permit plans per San Juan County requests and updating the application with the Area B site plan and stormwater plan. If the project is granted a Conditional Use Permit, the OPALCO Board will decide whether to move forward with the project. If it is decided to move forward with the project, OPALCO will apply for a building permit. We will post all updated materials as they are available

Yes, the website will be continually updated as plans are modified or completed. It’s standard that the design and the construction plans will be updated as the project progresses.

OPALCO is committed to keeping the community informed throughout the project. If you haven’t been receiving our email updates, please contact communications@opalco.com to get added to the list. We will have all complete information added to the website page dedicated to this project www.opalco.com/decatur.