Seattle may not be solar-panel savvy or a wind-power winner, but could it be a viable source of tidal energy? That’s what a number of scientists, governmental bodies, and public utilities folks are trying to figure out. And they shared their progress, and their plans for the future, with attendees at the Puget Sound Georgia Basin Ecosystem Conference in Seattle.

Generating tidal energy involves taking advantage of the rhythmic rise and fall of tidal currents by planting some sort of windmill-ish technology below the surface of the water, especially in areas where water flow is restricted into a narrow passageway, such as an inlet.

Like their land-based brethren, though, these underwater windmills could have environmental impacts that include affecting salmon and marine mammal migration, disturbing bottom fish habitat, and impacting fish harvests. But just how much of an impact would tidal power have on the Puget Sound — and how would that balance with the benefits of renewable energy generation? Well, unfortunately, no one really knows. There are limited studies on actual impacts — and limited on-site experimentation as well.

That’s why Craig Collar of Snohomish Public Utilities District is excited about a new project at Admiralty Inlet that would utilize a small-scale pilot plant to see how feasible a larger-scale effort might be. Collar says the Snohomish region is growing, and PUD is seeing some 10,000 new connections a year. Add that to the Renewable Portfolio Standard’s requirements that they seek out 140 megawatt-hours of new renewable energy sources by 2020, and it’s easy to see why Snohomish PUD might be looking seaward.

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The U.S. Department of Energy is also keen to harness the power of the oceans, awarding the PUD tidal project a $1.2 million grant last fall and putting more than $6 million toward 13 other clean technology water power projects, including the creation of a Northwest National Marine Renewable Energy Center. Part of a partnership between Oregon State University and the University of Washington, the Center will study both wave and tidal energy in the region.

But the DOE isn’t the only federal entity looking to tidal energy. The U.S. Navy wants in on it, too. Through a Congressionally directed and funded project, the Navy will be installing a demonstration project in the Puget Sound, said Peter Havens, Naval Facilities Engineering Command at Navy Region Northwest. They plan to use turbines from Verdant Power, a company that has also launched a pilot project in the Hudson River.

Unlike the Snohomish PUD project, however, the primary goal of the Navy’s pilot project is aimed at furthering the state of tidal energy technology by gathering operational and environmental assessment data. "We have no intentions to use this energy source for ourselves," Haven said, sending an audible wave of gasps through the audience.

"We need to get these projects in the water or we’ll never find out [if they’ll work]," said Rich Bowers of the Hydropower Reform Coalition. "Doing this on paper doesn’t work because it doesn’t translate into a deep water or a nearshore environment."

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Adam Harding, a second year student at Pearson College near Victoria, British Columbia, knows all about translating a paper-based proposal into real-life trial-and-error. He’s been working with the Pearson College-EnCana Clean Current Tidal Power Demonstration Project at Race Rocks, an ecological reserve on the Strait of Juan de Fuca.

For years, noisy, expensive generators had been powering the isolated research station; but in the fall of 2006, after an extensive feasibility study was conducted, a tidal power turbine was installed offshore and the island fell silent for the first time in many years. Unfortunately, the generators had to be restarted less than a year later for equipment upgrades on the turbine, and the system has yet to be put back online. Still, the project has been a great learning opportunity, Harding said.

And great learning opportunities are exactly what we need — but we should proceed at a slow, measured pace, Bowers warned, emphasizing small-scale pilot projects in areas that are not ecologically sensitive. Calling himself "a river person," Bowers reminded the audience that we haven’t always been the most forward-thinking when it comes to the effects of our actions on the surrounding watershed.

We don’t have baseline data for these burgeoning tidal projects, he said, and there’s no formal research about what the cumulative effect on the Salish Sea could be once it’s full of turbines.

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