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If you’re a customer of Snohomish County Public Utility District (PUD), one day some of your electricity could come from tidal power.

The Federal Energy Regulatory Commission voted unanimously Thursday to issue a license to the PUD for a tidal-energy pilot project in Admiralty Inlet.

If it gets final approvals, the pilot may be the world’s first grid-connected, tidal-energy project using large-scale turbines, said Assistant General Manager Craig Collar.

Commercial generation of tidal energy hasn’t been studied much; the license lets the PUD gather information to see if it might be feasible in this region, he said.

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The PUD has been working to bring tidal energy to the Northwest for a few years. If its pilot is successful, it will be in the forefront of energy technology. The Department of Energy predicts that by 2030 tidal power could create 15 percent of the electricity the nation produces.

Two other tidal projects — one in New York and another in Maine — have been studied, but neither is

the size of the one planned for Admiralty Inlet.

A wave-energy project begun not long ago off the shores of Oregon is also harnessing the power of water movement. But it gets energy from surface waves or from pressure fluctuations, while tidal energy captures the kinetic motion of ocean tides.

The Snohomish pilot calls for two turbines placed at a depth of 200 feet. The turbines, manufactured by OpenHydro in Dublin, Ireland, each measures 20 feet in diameter and weighs 414 tons. They are secured in place by gravity and need no pilings, said utility district spokesman Neil Neroutsos. Once installed, they’ll be in place for three to five years, according to a PUD news release.

Each turbine has only one moving part and requires no lubricating oils or greases that might harm the environment. Water currents turn the turbines, which activates generators, which in turn produces electricity. Underwater cables will connect the turbines to the electrical grid on PUD-leased land south of the Coupeville Ferry Terminal.

Admiralty Inlet offers attractive features for energy production, including swift currents, good access, a rocky seabed floor with little sediment and vegetation and viable connections to the electric grid. The inlet is a very large body of water — the footprint of the pilot plant will be small by comparison, which should minimize any environmental impacts, Neroutsos said.

The next step for Snohomish PUD is getting a permit from Island County, said Neroutsos. That’s supposed to happen fairly soon. The PUD’s Board of Commissioners also must sign off on the project.

The tidal project is funded by $13 million in grants from the U.S. Department of Energy, Bonneville Power Administration and federal appropriations. The University of Washington, Pacific Northwest National Laboratory, Sound & Sea Technology and the National Renewable Energy Laboratory are also partners in the project.

Times reporter Paige Cornwell contributed to this report.

Nancy Bartley: or 206-464-8522

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