Projects to test tidal power off Whidbey
April 3, 2009 · 4:16 PM
A busy shipping lane could provide a source of power public agencies are eager to harness.
The U.S. Navy and the Snohomish County PUD are undertaking pilot projects in Admiralty Inlet to gauge the effectiveness of something called kinetic hydropower. The two projects entail the installation of turbines that will generate electricity as tides flow in and out of Puget Sound.
The Navy is looking at two sites near Marrowstone Island, southeast of Port Townsend, while the PUD is considering a site west of Admiralty Head that is north of the ferry line and east of the shipping route.
The Navy examined a site near Deception Pass, but the extreme water conditions proved too difficult for the test project to move forward in the area.
“Studies on the area near Deception Pass revealed that tidal current was too turbulent for effective power generation,” Navy spokesperson Sheila Murray said in an email. She added that a final site hasn’t been selected yet.
As part of the National Defense Authorization Act of 2007, renewable energy sources must generate one quarter of the Navy’s power by 2025.
Installation for the Navy test project is scheduled to take place in the summer of 2010 and remain in operation for two years before the equipment is removed.
The Navy’s plans call for the installation of an array of three turbines that will have blades five meters in diameter. The array will take up 800 square feet. Congress approved $5.6 million in funding for the project.
Because the Navy and the Snohomish County PUD projects are in relatively close proximity, the two entities will share the environmental information gathered. The Navy is helping the PUD with gaining the proper licensing for its project, according to Murray.
Murray said the Navy is also assessing the project’s potential effects to commercial boat traffic. Offshore areas will be marked.
“The Navy will avoid adverse effects to commercial and recreational traffic,” Murray said.
The PUD is currently seeking a license from the Federal Energy Regulatory Commission for its project off Admiralty Head.
Craig Collar, senior manager for energy resource development for the PUD, said the pilot venture is designed to gauge the effects the turbines would have on the environment.
“There’s very little of this that is being done in the world, so there is very little data,” Collar said.
He said the project will likely take place in 2011 and will use slightly different turbines than the ones the Navy is planning to install.
The proposed turbines for the PUD project would be 10 meters in diameter and will move at 10 revolutions per minute. The project is expected to generate one megawatt worth of power.
The PUD is also eyeing Deception Pass to install turbines. That project is in its preliminary stages and won’t take place until the Admiralty Inlet project is complete.
“We don’t see having multiple developments,” Collar said.