N.S. Power to test new tidal power generator

Last Updated: Friday, January 12, 2007 | 5:27 PM ET

CBC News

Nova Scotia Power is looking at introducing in-stream tidal power, an alternative to placing dams across inlets or rivers to capture the energy of huge volumes of moving water.

The company has a deal with an Irish partner, which will build a test model of an in-stream tidal turbine in the Bay of Fundy, the Canadian Press reported Friday.

The Bay of Fundy has the highest tides in the world.

The one-megawatt installation, to be built by OpenHydro of Dublin, uses a different system than Nova Scotia Power's current 20-megawatt plant at Annapolis.

The existing plant harnesses the tidal action of the Bay of Fundy, site of the world’s highest tides, where a dam funnels the water into generators as it flows in and out with the tide.

In contrast, OpenHydro's turbines resemble giant fans with the blades connected to a rotor which spins slowly inside the structure as water flows through. Electricity is generated as the rotor turns past a magnet generator on the outer rim of the structure.

The whole "fan" is anchored to the ocean floor, and no dam is required.

The installation probably won't be operational before 2009, a NSP spokeswoman told CP, and it will require a turbine "farm" to produce significant amounts of power.

OpenHydro's website said the speed and volume of water passing through the area, depth and geology of the seabed and distance to a grid connection determine the cost and output of its turbines.

The turbines, with just one moving part, lubricant-free construction and no seals, give the design simplicity and strength, it said.  

The turbine could cost up to $12 million to develop and build, but Nova Scotia Power said in December it had asked Sustainable Development Technology Canada to share the cost.