||| FROM ELISABETH ROBSON |||


On Friday, March 28, the Federal Energy Regulatory Commission (FERC) sent out notifications that OPALCO has applied for a draft license application for their Rosario Strait Tidal Energy Project; OPALCO posted about this application on Saturday, March 29 here in the Orcasonian. The application is 523 pages long.

It’s unlikely most people in the county have read the entire application, or visited the website of the company that manufactures the tidal energy machine OPALCO would like to put into Rosario Strait, or watched the many videos the company has produced showing this machine. So, many may not realize what the O2X actually is. OPALCO describes the O2X made by Orbital Marine as a “device,” a word that brings to mind something rather small.


This “device” is approximately the size of a 747 aircraft in width and length. It weighs about four times more than a 747, and its blades are 30 times as wide as the engine of a 747—each O2X blade is 49 feet, making the diameter of each rotor at least 98 feet. This machine is massive. An online video shows some of the construction and moving of the O2 and you can get a sense of the monstrous size of the machine when humans stand next to it and are completely dwarfed by it.

OPACLO’s article frames the tidal energy project as a “new source of clean, locally produced, renewable electricity,” one that will “satisfy increased demand for electricity.” Yet, despite the massive size of the O2X, including a total swept area for both nacelles of 7,600 square feet, the machine will generate electricity only for an average of about 400 homes. This is about 4% of the approximately 9,000 households in San Juan County. And how much will it cost us to supply electricity to an average of 400 homes? $40 million for a machine that will last only 25 years.

OPALCO goes to great lengths to tell us the money to pay for the O2X will come from a federal grant. However, the machine will require $300,000 in annual maintenance, $550,000 refurbishment after each 10 years of operation, crew to maintain and inspect the machine, along with a manufacturing plant to put the machine together and get it installed after the parts have been shipped from the UK, along with the people to do that work. Will the grant cover all of that too? A “grant” is money from the US taxpayers, which is still us (although obviously spread out over many more people). Who will pay for the inevitable overruns? Who will pay for the insurance? Who will pay for clean up if something goes catastrophically wrong? Who will pay damages if someone sues OPALCO over this machine for violating the law or for the impacts of an accident? Who will pay if the tidal energy machine becomes a stranded asset?

OPALCO has claimed that the O2X will supply electricity in the event of a grid outage. At one of the town hall events in January of this year, I asked OPALCO about this, and they said that in the event of an outage, the power would be directed to a few emergency sites as of course a machine that can power only 400 homes would not be able to supply the entire county with electricity in the event of a grid outage. This power would be intermittent, as the machine only generates power with the tides; at slack tide, no power is generated at all. So even emergency power would not be on all the time. In addition, do we know if the County has the ability to direct power to emergency locations such as a warming shelter? If not, who will pay for upgrades to our grid to allow this kind of selective electricity supply?

OPALCO has claimed multiple times that they are following the engagement process with the affected tribes in the region. However, we know from a February 26, 2025 letter to FERC from the Swinomish Indian Tribal Community that the tribe is disgusted with how OPALCO has engaged with them. They write in their letter that there appears “to be limited effort to engage the Swinomish Tribe as equal partners in decision-making,” and OPALCO has been “overwhelmingly non-responsive” to the Tribe’s concerns.

The Swinomish previously raised many questions and concerns back in October, 2024, long before our community was aware OPALCO was planning to submit a preliminary permit application to FERC on January 15, 2025. OPALCO’s canned response to most of their concerns was that more information would be forthcoming when the draft license agreement was filed. Now that OPALCO has filed this draft license application, we hope to hear more from the Swinomish Tribe about whether any of their concerns are adequately addressed.

In the meantime, my assessment of the draft license application is that it does not fully address my own concerns, many of which mirror those of the Swinomish Tribe. To take just one of many examples, the Swinomish filed a concern about the deployment of anchors and mooring systems that will likely have a significant impact to the benthic environment. At the time the Swinomish filed their concerns (in fall, 2024), OPALCO responded by saying “A detailed analysis, using the best scientific information, will be used to evaluate potential effects of the anchoring and mooring systems to the benthic environment in the Draft License Application.”

We learn from the draft license application that the catenary mooring system, consisting of four mooring chains and anchors, will drag across the seabed and potentially impact an area up to 1056 feet by almost 2000 feet.

The area where the O2X would be installed is Essential Fish Habitat (EFH) and within the Marine Biological Preserve, and yet there is the potential to completely destroy a large area of benthic habitat due to the sweep of mooring lines as the machine pivots with the tides, twice a day.

From my studies of floating offshore wind turbines, I know that aside from the direct damage inflicted by chains scraping across the seabed, this scraping motion can also raise significant amounts of sediment that can damage an area of marine habitat far larger than the area directly impacted by the chains. OPALCO claims that “while the northern part of the turbine area appears sedimented, this sediment layer is likely very thin.” Perhaps we won’t know about potential sediment disturbance until the machine is in operation unless more studies of the seabed are completed.

In addition to the mooring lines, 4 gravity anchors measuring 36 feet by 36 feet by 8.2 feet and weighing 35 tons each may be used to keep the mooring lines in place, if rock anchors are not used instead. This is another 120 square feet of damage to the seabed.

Other potential impacts to the benthic habitat as well as to all marine life in the area of this machine are the effects of corrosion from the blades and of the antifouling coatings applied to the exterior and interior surfaces of the machine that are exposed to seawater. These antifouling coatings—biocides—typically contain metals, including aluminum, zinc, copper, and indium, all of which are toxic to marine life in high enough quantities. A recent study in Nature’s npj Ocean Sustainability found that metals from the erosion of these coatings from offshore wind turbines can accumulate in marine species.

The O2X’s spinning blades are glass-fiber reinforced epoxy, meaning they include plastic. As we know from offshore wind turbines, these plastics are shed in huge quantities over the lifetime of turbine blades, contaminating the marine environment with thousands of pounds of microplastics over the lifetime of the blades. While the blades of the O2X are smaller than a wind turbine’s blades, we can assume that these blades will likewise be shedding microplastics into the marine environment, an environment already chock full of microplastics that is poisoning marine life and killing plankton.

While OPALCO likes to frame this massive experiment they are planning to perform in the Salish Sea as “clean energy”, this machine is anything but “clean” in its potential impact to the marine environment. It will cost many millions of dollars to produce a tiny 4% of the county’s average electricity use, electricity that will be eaten up by new housing within a mere 4 years at current growth rates in San Juan County.

I would urge all San Juan County residents to read the materials related to this project, which I have gathered and posted at Protect The Coast Pacific Northwest under Tidal Energy Project – Washington.



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