2-for-1 Narrows proposal: new bridge, power source
TACOMA - A Canadian energy company has an idea for addressing two contentious regional issues: the Northwest energy crunch and congestion on the Tacoma Narrows bridge.
Blue Energy Canada of Vancouver, B.C., proposes to build a second bridge beneath the 50-year-old span and put turbines underneath that would harness tidal forces to generate electricity.
Martin Burger, company president and chief executive, says Washington state would wind up with a second Narrows bridge - at no cost to taxpayers and without tolls - in exchange for power-generating rights.
Burger recently pitched his idea to David Danner, Gov. Gary Locke's energy adviser.
"I think this is a technology that has a lot of potential, and we have to take a hard look at it," Danner said. "But I don't think the proposal is ready for prime time. There's going to be transmission issues. There's going to be shoreline issues. There's going to be (State Environmental Policy Act) issues."
Danner said he expects tidal power to be part of Washington's energy future but reserved comment as to whether it was likely to come about through the bridge proposal.
`Two birds with one stone'
One problem with Burger's plan is that the state has bought into a different one. Officials have contracted with United Infrastructure Washington to build a second suspension bridge across the Narrows - parallel to the existing span - and charge tolls to pay for it.
Burger envisions a four-lane bridge - two lanes in each direction - near the surface of Puget Sound, looking much like the Interstate 90 floating bridge across Lake Washington.
Below the road surface, mounted to the seabed, would be a series of turbine rotors - spaced 36 feet apart and spinning slowly in the swift Narrows current to generate electricity.
A section of the bridge would be raised periodically - for 70 minutes every six hours - so ships could pass, Burger said. Traffic would be rerouted to the original span when the bottom one is closed for ship traffic.
Burger says the bridge and power station could be built in about two years. He figures the system could generate about 440 megawatts, enough to power about three-quarters of Tacoma's daily load and about one-third of Seattle's.
The plan is environmentally friendly, he said.
"There are no mash points to mulch or kill the fish," he said.
As for larger creatures, Burger said sonar technology would alert computers to shut down the system when "anything larger than a beach ball" approached the rotors.
Harnessing ocean waves and tidal power to generate electricity is not new. Several countries are already doing it.
Tidal power is one of several alternative forms of energy generation - including wind, sun and geothermal power, fuel cells and clean coal - being studied by Tacoma Power officials, supervisor Steve Klein said.