PUD to share details on tidal power

EVERETT -- Snohomish County PUD customers are invited to learn about their utility's growing infatuation with tidal energy.

The PUD, in the early stages of studying whether it can plant fields of tidal turbines on the floor of Puget Sound, wants to share what it has learned about the renewable energy source at a Tuesday evening meeting.

"It'll be a broad overview," said Craig Collar, PUD senior manager of energy resources development. "(We're) going to go all the way back and talk about why we're pursuing this in the first place."

The PUD estimates it could install 1,662 turbines at seven locations in Puget Sound, including at Admiralty Inlet and at Deception Pass.

In filings with federal regulators, the PUD estimated it could generate 100 megawatts of electricity, enough for 60,000 homes, or about every house and apartment in Mukilteo, Everett and Marysville. That initial assessment suggested Admiralty Inlet alone could produce 75 megawatts of electricity, more than the potential identified at the other six sites combined. Now, after a first wave of measurements has been taken, utility officials believe the currents between Point Wilson and Whidbey Island are even stronger than expected.

The PUD is in the beginning stages of a three-year study into whether tidal power is feasible in Puget Sound. If all goes well, it could put its first test turbine in the water by 2010. By the time this year is done, the PUD will have spent about $350,000 on developing tidal energy here, with $200,000 coming from the Bonneville Power Administration, Collar said. The utility is seeking another grant for costs expected in 2008.

To find out if the technology is feasible in Puget Sound, the utility is launching studies on the environmental impacts of tidal power, Collar said. It's also trying to decide which type of tidal turbine would be best for Puget Sound.

Area tribes and environmental groups have been watching closely. They worry about the effect on endangered chinook, orca and other marine wildlife.

In addition to Admiralty Inlet and Deception Pass, the PUD's study sites are Spieden and San Juan channels in the San Juan Islands, Guemes Channel near Anacortes, Agate Passage near Bainbridge Island and Rich Passage near Bremerton.

Tidal power generates electricity by harnessing the ebb and flow of tides with windmill-like turbines.

The utility's venture into tidal power could help it meet a voter-mandated requirement to provide substantially more renewable energy over the next 15 years.