A PUD is studying the waterway’s tidal action for generating electricity.
Forever obstinate, the tidewaters that surround Bainbridge Island swell and recede each day at traceable intervals.
Nappers on beach towels fear their approach. Seafarers look upon them with humility. Steadily lapping at the shoreline, they remind those on land of the power of the sea.
That power is visible from land and palpable from Barry Peters’ kayak, which is often aided by Puget Sound’s methodical slither between the island and the mainland to the north.
“If you catch it right, it’s wonderful,” said Peters, of the currents coursing through Agate Passage. “There’s a vast amount of energy in the water. You definitely don’t want to be fighting against it.”
Mindful of that, developers in the nascent tidal energy industry have ridden into Puget Sound on a wave of optimism, hopeful that deep waters and strong currents will yield energy that is both cost-effective and environmentally safe.
To the south, Tacoma Power is already studying the feasibility of harnessing tidal power in the Tacoma Narrows.
Meanwhile, Snohomish County PUD is seeking the rights to study seven potential tidal energy sites in Puget Sound, including Agate and Rich passages, for a project that could power up to 60,000 homes.
Development is in its earliest stages, with costs, environmental impacts and even the precise mechanisms by which the energy harnessing would take place still largely unknown.
Early prototypes use submerged turbines that swivel to meet the tide and rotate under the power of the current to generate electricity.
Advocates say tidal energy is more predictable than wind power, and less permanent and obtrusive than dams.
The push for tidal energy is occurring alongside efforts to harness energy from waves, which are much more common than suitable tidal straits like those in Puget Sound.
“The wave potential alone, if we utilized 15 percent of the resource, would be comparable to all the hydro that’s built out today, in terms of annual energy production,” said George Hagerman, a senior research associate at Virginia Tech, at a December conference held by the Federal Energy Regulatory Commission to study the implications of sea-generated energy.
Although it can only be developed in certain areas, Hagerman said the potential for tidal energy is great.
“The unique and true of (tidal currents), is that they are totally deterministic,” he said. “(they are) totally determined by the position of the sun, the moon and the earth, which we can predict with great astronomical accuracy.”
Less reliable, according to Roger Bedard, of the Electric Power Research Institute, is the government’s responsiveness to development efforts. Bedard is helping both Tacoma Power and Snohomish County PUD as they enter the early stages of their research.
Like Hagerman, he believes the opportunities for tidal power, especially in the Puget Sound region, are very real. For now, he said, bureaucracy is the largest hurdle.
“My biggest beef is with the regulatory process,” Bedard said. “People want renewable energy, but the government right now is standing in the way.”
FERC, the agency responsible for issuing permits that allow research at potential tidal energy sites, has put a freeze on permitting pending further study of the technology.
The decision came last year after the commission received a deluge of permit applications by groups eager to snatch up the rights to promising waterways.
Tacoma Power was one of 11 entities around the country issued a permit before the freeze.
The three-year permits authorize no construction, only study of the possibility and first right of refusal for the development of tidal energy at specific sites. The Snohomish County PUD project is among 40 permits stalled by the freeze.
But for one of the technology’s frontrunners, turbines are already taking root 30 feet below the surface of New York’s East River, a tidal strait that runs between Long Island and Manhattan.
By submerging two turbines in the river in December, Verdant Power is the first group in the country – and among the first in the world – to successfully harvest energy from the tides using the still-developing turbine model.
The two turbines have rotors that are seven meters in diameter and, at the lowest tide, allow boats passing above about six feet of clearance. Both are surrounded by booms and are not installed in shipping channels.
The turbines have thus far met varying degrees of success. The first sputtered early on, but the second was able to power a supermarket on Roosevelt Island for 40 days before an unknown object damaged one of the rotors.
“It exceeded our expectations,” Taylor said, of the turbine’s performance in an area known as “asthma alley” because of power plants that line the shore and spew pollutants into the New York sky. “And the great thing is that, unlike a lot of proposed projects, the people of Roosevelt Island actually want this in their backyard.”
In the coming months, Verdant will install four more turbines. Over an 18-month period, the turbines will power the same Roosevelt Island supermarket, along with a neighboring parking garage.
Along with studying the effectiveness of the technology, Taylor said the company will study its environmental impacts, in particular the potential dangers it poses to fish and other underwater life.
The $6 million project has thus far survived mostly on private funding, but success is slowly attracting bigger players, including KeySpan, a corporation that powers much of New York.
Verdant hopes to install 300 turbines in the East River, enough to power 10,000 Roosevelt Island homes. For now, Taylor said the technology is too expensive, particularly when it comes to capital costs, but as technology improves he believes it will become “commercially viable.”
A major consideration is how much power to extract from the water. Placing fields too close together could have too drastic an impact on the currents, Taylor said, especially in shallower waterways.
Taylor said Puget Sound, which has deeper and faster waters than the East River, is a “treasure trove of tidal power,” but local projects are still several years off.
Tacoma Power has only just begun its study of the Tacoma Narrows, according to spokesperson Sue Veseth.
“We’re not anywhere near making a decision,” she said. “It’s a fairly deliberate process involving a lot of math.”
Snohomish County PUD is even further behind. Still, recognizing the potential, the utility company has mapped out a plan that would kick in if and when FERC issues a permit.
Following approval, the PUD would spend a year or two studying its sites before deploying a pilot device. Even if the plan makes it that far, there are no guarantees it would come to fruition, said PUD spokesperson Craig Collar.
“For this to make sense for us, we need to know that it would be technologically, economically and environmentally viable,” he said. “It’s certainly a compelling opportunity. It would be irresponsible for us not to investigate it further.”
The project has the backing of Congressmen Jay Inslee, a Bainbridge Democrat, and fellow Democrat Rick Larsen, both of whom wrote a letter to FERC offering their support.
Even with political backing and the proper permits, none of the local tidal energy projects are likely to escape scrutiny. Some cities, including Bainbridge Island, have filed motions to intervene with projects taking place along their shorelines.
Local tribes have also jumped in the mix, concerned that spinning rotors pose a danger to fish and other marine life in Puget Sound. Based on early results elsewhere, both Taylor and Bedard believe the turbines are safe.
“It turns out the fish ain’t that dumb,” Bedard said. “In most cases they recognize the machines and swim around them.”
In Canada, where fewer regulatory hurdles exist, a number of tidal and wave energy projects are under way, said Chris Campbell, of the Ocean Renewable Energy Group, a Canadian trade association.
Since December, a turbine has been submerged in Race Passage, between a series of small islands and Vancouver Island. The turbine is now powering a nearby marina that once relied on diesel generators.
Like the Verdant project, Campbell said, the Race Rocks project is still in the early stages, but Clean Current Power Company, the group behind it, hopes to one day connect to the main power grid on Vancouver Island.
“Were talking about a pretty huge resource,” said Campbell, of tidal and wave energy as a whole. “The tide is predictable. It’s not going to be affected by climate change. It’s going to be a very reliable long-term energy source.”
Campbell went on to compare the current state of tidal energy to the earliest home computers.
“The whole wave and tidal industry is where the wind industry was 20 years ago,” Campbell said.
“But as everyone knows, we had to go through the Commodore 64 phase to get to where we are today.”
