CHIMACUM — Sea-turbine blades are on the cutting edge of alternative power-generating technology.
At about 16 feet in diameter and weighing more than 4 tons, three undersea turbines mounted on a 40-ton frame are proposed to be sunk off the northern or southern end of Marrowstone Island as part of a U.S. Navy tidal energy kinetic hydropower system test in Admiralty Inlet.
The turbines will be anchored with the aid of gravity about 70 feet down in the strong currents off either Marrowstone Point, north, or Nodule Point near the island’s south end.
A similar array is already being successfully tested in the East River of New York, said Aaron Hernandez with Verdant Power, a Navy contractor based in the same city. It is powering a parking garage and grocery store there.
“It’s the first technology like this to be demonstrated,” said Hernandez at his information station, part of a Navy Region Northwest open house staged at Chimacum Elementary School Library.
Aside from fielding questions, Navy personnel including Cmdr. Mark Loose, commanding officer at Naval Magazine Indian Island, were on hand to hear comments and inform.
Comments will be taken as part of the environmental assessment process.
During the first of two hours, the event drew more than 45 people from Port Townsend, Port Hadlock, Port Angeles, Sequim, Nordland, Port Orchard, Rushton, even Corvalis, Ore.
Those interested milled about several information stations covering everything from turbine specifications and locations under consideration to the Navy’s plans to conduct the environmental assessment and secure permits over the next two years.
Once those permits and authorizations are secure, the turbines designed and built by Verdant will begin to spin at up to 35 revolutions per minute, generating 35 to 40 kilowatts each.
U.S. Congress has appropriated $5.6 million for the project, which will involve a single array of up to three triple-blade free-turning turbines. The project, which could be launched in 2012, is intended to test the effectiveness of tidal power in the area.
Electricity generated during the demonstration will be routed to an isolated electrical load at Naval Magazine Indian Island, not directly connected to Puget Sound Energy’s privately generated power systems or utility grid, as proposed.
Loose said that power generated would be used for Naval Magazine Indian Island’s administrative offices if the south site is chosen.
He said if the north site is selected, power would go to a Naval Magazine pier.
Michael McCallister, a Navy contractor with Lynnwood-based Sound & Sea Technology Engineering Solutions, said the south location was shaping up as the best turbine drop site.
“The current is bi-directional at south Marrowstone,” McCallister explained, which would allow the turbine blades to spin in either direction, generating more power. “We think the bottom here is more favorable and the current is more favorable.”
If the south Nodule Point location about a mile off the shore is chosen, a 4-mile-long cable about 4 inches in diameter would be laid along the shoreline west to Jefferson County’s south Indian Island park across from the gated entrance to the Naval Magazine.
A tunnel would be bored to avoid eelgrass beds near the shore, run under the park and state Highway 116 fronting the Naval Magazine, McCallister said.
The cable has a fiber-optic core capable of carrying digital commands to the turbines, he said.
An “active acoustic fish monitor” would be used during the demonstration project with a fish finder scanning the water columns during turbine operations to visually monitor the impact on fish and mammals.
Steven Towers, the principal with Navy contractor Querus Consultants based in Redding, Calif., staffed the environmental impact table, saying the Navy demonstration project would involve “very intensive monitoring” for any possible effects on marine mammals.
“If a marine mammal would be threatened by this project, the Navy would change the project by either addressing that or ending the project,” Towers said.
So far, the East River project has only encountered striped bass runs, which swam around the turbines, he said.
Elsewhere in other smaller, unrelated projects, he said, harbor seals have naturally avoided the turbines.
The project will first undergo a permitting process with about six federal and state agencies and comply with federal laws including the Endangered Species Act, Marine Mammal Protection Act and the Clean Water Act.
Brady Scott, state Department of Natural Resources aquatic district manager based in Chimacum, attended the open house and said the project would require an aquatics use authorization from DNR, which owns the tidelands.
Public information, environmental assessment, public review and comment, and the Corps of Engineers and state Department of Ecology permit period is scheduled to take two years.
The demonstration project would provide environmental and operational information to help understand the operating capabilities and environmental effects of tidal kinetic hydropower systems in Puget Sound.
The Navy will consider comments on environmental aspects to be considered in the environmental assessment through Aug. 1. Written comments may be submitted at the open house, online at www.nps-khps.net or by e-mail to peter.havens@navy.mil.
Mail to: NPS-KHPS, Naval Facilities Engineering Command Northwest, attention: Peter Havens, 1101 Tautog Circle, Silverdale, WA 98315.
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Port Townsend-Jefferson County Editor Jeff Chew can be reached at 360-385-2335 or at jeff.chew@peninsuladailynews.com.
