4/22/2009 6:00:00 AM Snohomish PUD, Navy move ahead with underwater turbine projects
With Whidbey Island's Admiralty Head Lighthouse in the background, University of Washington researcher Sam Gooch watches as his colleagues Chris Bassett and Dave Sutherland prepare to launch the Sea Spider, a device that will measure sea conditions in Admiralty Inlet over the next eight months. The project is part of Snohomish PUD’s plan to install up to six tidal turbines in the area. Photo courtesy of University of Washington
This conceptual drawing shows an OpenHydro underwater tidal turbine. It’s the same design that Snohomish PUD plans to use in a pilot project about a half mile southwest of Admiralty Head.
By Justin Burnett of the Whidbey Examiner
By 2011, as many as nine turbines between Marrowstone and Whidbey islands could be generating electricity from Admiralty Inlet tidal exchanges.
Both Snohomish County Public Utility District and the U.S. Navy are working to implement pilot projects that will employ the use of underwater, electricity-producing turbines that exploit tidal power as a form of renewable energy.
According to Neil Neroutsos of the Snohomish PUD, the utility's power demands have grown considerably, and exploring new, renewable sources of energy is increasingly important.
Considering the utility's proximity to the tidal waters in the north Puget Sound region, it makes sense to explore the possibilities of kinetic hydropower.
Snohomish PUD recently nailed down the perfect test spot to install as many as three turbines, which could power as many as 700 homes. The site is about half a mile southwest of Admiralty Head in about 200 feet of water.
Neroutsos said the plan is to install the turbines by 2011. If the pilot project yields good results, both in performance and for the environment, Snohomish PUD would move to install enough turbines to generate 100 megawatts of energy, enough to power about 70,000 homes, Neroutsos said.
"The pilot project is really to discover potential impacts and gather data," Neroutsos said. "It will allow us to see if these things really make sense in Puget Sound."
In an attempt to learn more and to make use of leveraged federal dollars, Snohomish PUD is working on the project with University of Washington researchers. Earlier this month, scientists from the Applied Physics Laboratory spent four days aboard the university-owned MV Jack Robertson gathering data about the site in Admiralty Inlet. They also installed and left behind a high-tech information-gathering device called a Sea Spider.
"This is a long-term monitoring effort," said Jim Thomson, one of several research team leaders on the trip.
The Sea Spider will stay underwater for eight months, collecting data such as current velocities, acoustics and water temperature. Thomson said it would be retrieved and serviced at least once during that period.
While the Sea Spider is only about the size of a desk, it weighs 700 pounds. Its extreme weight allows it to remain stationary without having to use environmentally destructive measures such as drilling or installing pilings.
The turbines proposed for the project would be held in place the same way. Made by OpenHydro, a company based in Ireland, the turbines will be anchored by extremely heavy tripod structures. While Thomson did not know exactly how much they weigh, he said it would be enough to ensure the turbines can't be disturbed.
That and other aspects of their design, such as an enclosed fan and the lack of oils and lubricants, make the turbines an environmentally friendly choice, said Neroutsos.
Some local residents remain concerned about the potential effects on the marine environment.
Howard Garrett, president of Orca Network, said he supports the pilot project because the information gathered will reveal any adverse environmental effects. While the effects on marine mammals is expected to be negligible, Garrett said some studies have indicated that tidal turbines used on a massive scale can hinder or slow the natural flushing actions common to areas such as Puget Sound.
"That could hold pollutants longer in Puget Sound," Garrett said.
Thomson agreed that reduced tidal flow is a concern and is one of the things the pilot project hopes to evaluate. Some computer models have shown that 100 turbines could slow tidal flow by about 1 percent, he said.
However, just a few turbines should not be a problem.
"It's like putting a pinwheel in a waterfall," Thomson said.
The Navy also has plans to temporarily place up to six tidal turbines in the waters on Admiralty Inlet's west side as part of a federally funded feasibility study. The turbines, which are to be installed in 2010 and removed in 2011, would power two buildings and parking lot lighting at Naval Magazine Indian Island.
Navy Environmental Public Affairs Officer Sheila Murray said the turbines likely would be installed off the west shore of Marrowstone Island. U.S.-based Verdant Power will supply the turbines, which look like underwater windmills.
Murray said the Navy's plans have less to do with an interest in power generation or renewable energy than they do with satisfying an order by Congress. Congress directed the Navy to study kinetic hydropower in Puget Sound, appropriating $5.6 million for the project.
"The Navy is not in the business of generating power," Murray said. "That's not why we're doing this."
Before either of the two pilot projects can move forward, they will need to go through an approval process. The Navy project must follow requirements outlined in the National Environmental Policy Act, while the Snohomish PUD project will require federal, state and local permits.
Reader Comments
Posted: Saturday, August 08, 2009
Article comment by:
Zeljko
It is nice idea! I am living in Croatia, and work in company whish take care of lighthouses. We use solar, wind and oil energy, but this is a nice idea for "green" energy. So do you be so kind to help us, we need small generetor to 1-2 kW. Do you have some company which produce so small sea gen. Best regards, zeljko.
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