Researchers from the University of Washington are investigating the feasibility of tidal turbines for generating electricity. With a significant dearth of information available for tidal turbine technology, this series of projects will shed light on the overall potential of the product.
“There really isn’t that much information, anywhere, about the environmental effects of tidal turbines,” said Brian Polagye, UW research assistant professor of mechanical engineering. “The results of this pilot project will help decide if this is an industry that has potential for going forward at the commercial scale, or if it stops at the pilot stage.”
The Snohomish County Public Utility District which resides just north of Seattle in America’s northeast received a $10 million grant from the Energy Department for the tidal project which is now in the final phase of obtaining permits.
The proposed turbines would generate an average of 100 kilowatts of electricity, enough to power 50 to 100 Washington homes during the pilot phase.
However the UW team need to focus their attention on the possible effects the project could have on the environment. “We want to monitor the effects of this particular project, but also understand the processes so we can apply the findings to other potential tidal energy sites,” Polagye said.
“There’s surprisingly little known about the oceanography of these very fast waters,” said collaborator Jim Thomson, a UW assistant professor of civil and environmental engineering and an oceanographer in the UW’s Applied Physics Laboratory. “These kinds of tidal channels where water is going very fast only happen in a few areas, and have not been well studied. The currents are so fast that it’s hard to operate vehicles and maintain equipment. And it’s too deep for conventional scuba diving.”
One possibly surprising field that the researchers will be focusing their attention is that of underwater noise. “When currents were more than about 2 knots the instruments are hearing considerable self-noise,” Polagye said. “It’s similar to when you’re bicycling downhill and the air rushes past your ears.” This is extremely important if there are marine mammals that use auditory cues to navigate the area or communicate with one another.
The Washington state tidal turbine project is one of three currently in the works in the United States, the other two being in Maine and Alaska.