Monday, November 2, 2009

Bay of Fundy Turbines will produce "Red Energy" not "Green Energy" - Dadswell



From the Working Waterfront. Read the entire article here: http://www.workingwaterfront.com/online-exclusives/Parallel-44-Tidal-power-takes-two-steps-forward/13496/


Tidal power also has to prove what most have assumed: that devices will have no discernable effect on the environment or fish populations. Mr. Sauer says video monitoring during the year-long testing of their prototype indicated marine life never attempted to enter the turbines. "Fish can sense a sold object ahead and appear to swim around it," he says.
Not everyone is convinced, least of all Mike Dadswell, a professor of biology at Acadia University in Wolfville, Nova Scotia, which is located near the Minas Basin test area. In July he wrote Nova Scotia officials that the test project there had the potential to kill large numbers of fish that migrate to the head of the Bay of Fundy. "Tidal energy will not be ‘Green Energy" but rather ‘Red Energy' from the blood of its victims," he wrote.

"It's literally impossible to turn a blade in the water and not kill, maim, or harm some fish," says Dadswell, who has conducted extensive monitoring of fish kills at an old-fashioned dam-based tidal power plant at Annapolis Royal, Nova Scotia. At that 25-year old facility, sturgeon, herring and other fish wishing to travel to and from the Annapolis River are forced to swim through concrete tubes and the spinning generator blades, which kill by impact and pressure changes.
He says the Minas Basin turbines operate on the same physical principles and will also kill many of the fish that swim through them. If 200 to 300 devices are eventually deployed as supporters hope, the damage could be devastating to fisheries throughout the Bay of Fundy.  "The fish aren't forced to go through the turbine there, so it all comes down to fish behavior, whether fish approaching these machines will know to turn away," he says. Proponents say Dadswell's conclusions drawn from an old dam-based system don't apply to the new devices, which fish are free to swim around. "With these devices there's no sucking and none of that-the physics are totally different than at Annapolis Royal," says Sauer. "You have a little itty-bitty piece of equipment in a huge area of water with no physical pressure pulling things into it."