ns-hydro-turbine

A commercial tidal turbine was lowered into the Bay of Fundy in November. ((CBC))

Two blades on a large experimental turbine have broken off in the Bay of Fundy, forcing Nova Scotia Power to pull the device out of the water a year ahead of schedule.

The utility and its partner, OpenHydro, said it will retrieve the turbine between August and October — depending on the weather — to find out what went wrong.

Representatives from companies said Friday that the damage was discovered in late May, when they were finally able to get a camera down to the turbine.

A two-second video clip showed two of the blades, made from blends of plastics and glass, have broken off the turbine.

Mark Savory, the vice-president of technical and construction services for Nova Scotia Power, said the setback would not dampen the resolve of either company. 

"It's a challenging environment, we've always known that," he said. "What comes with the world's biggest tides is a very aggressive environment.

"So I guess we're not terribly surprised that it is a tough place to work."

The estimated cost of the project was $8.5 million.

The turbine began turning in the Minas Passage, about 10 kilometres west of Parrsboro, N.S., last November in a test of tidal power's potential for the province.

Nova Scotia Power's turbine is one of three commercial projects that were also designed to examine how marine life, including fish and whales, would be affected by tidal power. The other two groups chosen to test turbines in the Bay of Fundy haven't deployed their devices yet.

Savory said the damage to the turbine was likely not connected to the death of a whale found on a nearby beach earlier in the week.

Cause unknown

When asked if sea ice could have played a role in breaking the blades, Savory said it was too early to speculate.

"We don't know until we do the detailed engineering," he said.

"We have lots of belief that with our data collection systems that we have — and we've got six on this unit — we'll be able to actually determine exactly what has happened."

Peter Corcoran, the chief financial officer of OpenHydro, said his Irish tidal company will pay to retrieve and repair the turbine, and Nova Scotia Power customers won't bear any of the cost. Neither company would say how much the process would cost. 

This is not the first time the Nova Scotia Power turbine has faced a challenge. Within a week of the turbine being lowered to the Bay of Fundy floor, the companies lost contact with an onboard wireless sensor that was supposed to send continuous data to the surface.

With files from The Canadian Press