Nova Scotia looks at tidal power

August 29, 2007 - Exclusive
By David Ehrlich, Cleantech Group

According to local legend in Atlantic Canada, a giant whale in ancient times made such a splash with his mighty tail that the water in the Bay of Fundy sloshes back and forth to this day.

Getting power from that giant splash could be only a couple of years away, as the Nova Scotia government appointed Offshore Energy Environmental Research group just completed a round of six community forums on tidal power in the bay.

Nova Scotia Power has already partnered with Ireland's OpenHydro Group to provide in-stream underwater turbines and expects to have a 1 megawatt demonstration unit in the water in 2009.

Take a look at a turbine here >>

But nothing goes in the water until the research group releases its report next spring.

"We will do what we can do in that timeframe. We've got a fairly large mandate to try and cover, and we absolutely know right now that there are questions that just can't be answered by April," Lesley Griffiths, with Offshore Energy Environmental Research, told Cleantech.com.

Griffiths is leading the strategic environmental assessment at OEER.

"People have tried to develop tidal power here in Nova Scotia for over a hundred years," said Margaret Murphy, spokeswoman for Nova Scotia Power.

The utility's $12 million project could have some competition, as the provincial government recently released its own request for proposals for independent companies to test out their own tidal turbines in the bay.

There are only a handful of underwater turbine projects in operation around the world, and none are running at a commercial scale, making it a difficult project to assess.

"If this were to go ahead, can fishing and tidal in-stream turbines co-exist without significant problems?" asked Griffiths.

"Could it end up that you get a change in sedimentation patterns, could you end up with changes in tidal level?"

Interest in the bay was spurred by a survey released last year of potential tidal energy sites in North America.

The Electric Power Research Institute in Palo Alto, Calif., found that most of the best sites were in the Bay of Fundy.

The province already gets about 11 percent of its power from renewable energy, and has one of only three tidal power plants in the world.

The 20 MW barrage style plant, built in the 1980s in the Annapolis Basin, just off the Bay of Fundy, uses a dam to funnel water into the tidal generating plant.

France has the largest barrage system, with a 240 MW plant on the Rance River. Russia has a much smaller plant, less than 1 MW.

The barrage system has since fallen out of favor for being too damaging to the environment.

The current tidal proposal is similar to a system being tested on a much smaller scale in the East River in New York City by Verdant Power (see Verdant deploys tidal power array in New York).

Murphy said the senior manager on Nova Scotia Power's tidal project has met and talked to the president of Verdant.

"It's not a large group of people, so everybody tends to know one another's projects and be watching closely," she said.

Murphy said the tidal power project probably won't be scaled-up in time to help with a provincial goal of 20 percent by 2013, but the utility has a request for proposals out for 130 MW in renewable energy.

Those proposals, likely to be mostly wind, are due by the end of this week.

In the meantime, the OEER will be looking at projects like OpenHydro's current pilot plant in Orkney, Scotland, to collect the data for its report.

But it may be a case of comparing apples to oranges.

"How comparable are the locations?" she said. "The Bay of Fundy is going to be quite an operationally challenging place, because of those huge currents and because of, in some areas, the big sediment load that's carried."

"It's going to be challenging just to get these things installed and to see what kind of maintenance they need," said Griffiths.


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