NOVA SCOTIA Power and its Irish partner OpenHydro ran out of time Monday and failed in their first attempt to remove their 400-tonne turbine from the bottom of the Bay of Fundy.
"We definitely had it in the frame and we are just running out of time, so unfortunately we are looking at another repeat operation tomorrow but with a little more experience," said OpenHydro president James Ives, who was on board the barge and giving instructions to the crew on a marine radio.
Ives made the decision shortly before 12:30 p.m. to abort the operation after engineers and tugboat crews had worked for hours trying to position the catamaran-style barge Installer over the turbine.
They were trying to lift it up to the barge before the tide started to come back in but they ran out of time.
The one-megawatt turbine, almost as tall as a six-storey building, is designed to harness the tidal action of the Bay of Fundy to generate enough electricity to power 300 households, but it is being pulled out of the water a year before the end of its scheduled testing period.
The retrieval operation, shrouded in secrecy, started at about 4:30 a.m. Monday in the Minas Channel, part of the Bay of Fundy about 10 kilometres west of Parrsboro.
The open-centred turbine and its subsea base are 16 metres in diameter, and crews tried to lift the unit using winches.
Closely watching the operation was John Woods, vice-president of Minas Basin Pulp and Power of Hantsport.
"All of us are benefitting from OpenHydro’s experience and expense," said Woods, whose company plans to launch its own test turbine in 2012.
He was anxious to see how OpenHydro stationed the barge and handled the wind and powerful tidal currents.
"We have pictures of how they got it down, and now we need to know how they stay on station and with tides and wind interaction," said Woods.
Representatives of government, business and academia were also watching from two chartered fishing boats. Among those on board was OpenHydro’s insurance broker, Alex Dunlop of Halifax.
"Anything, when you are dealing with prototypes (and) with heavy masses of water like this, is extremely risky," said Dunlop, who works for the global renewable energy insurance company AON of London, England.
The recovery operation is the first for a commercial-size underwater turbine, he said.
"It’s new technology, so we don’t really know a lot about it."
Dunlop said AON is interested in learning about the costs involved in bringing such a massive underwater turbine to the surface.
The turbine stopped transmitting information a mere seven days after it was lowered to the ocean floor almost exactly a year ago. The acoustic modems intended to allow crucial data to be recovered from the turbine didn’t work, and several attempts to activate them failed.
This summer, Nova Scotia Power and OpenHydro revealed that two blades had snapped off the turbine. The damage was discovered in May when a video camera was lowered 15 metres into the murky waters to film the turbine and caught the image in a two-second clip. Then the companies decided it was time to bring the turbine up and find out what had gone wrong.
Although it was always touted as experimental, it was Canada’s most ambitious attempt at harnessing the tides with a commercial-scale turbine.
The demonstration turbine cost $10 million, with Nova Scotia Power investing the lion’s share and $4.6 million coming from Sustainable Development Technology Canada, a non-profit green energy foundation.
Two other test turbines are expected to be placed in the Bay of Fundy by 2012.
Clean Current Power Systems Inc. of British Columbia and its partner, international industrial giant Alstom of Switzerland, will deploy one turbine, and Minas Basin Pulp and Power and its partner, Marine Current Turbines Ltd. of Bristol, England, are handling the other.
The tests are intended to determine how turbines on the floor of the Bay of Fundy would affect marine life, including fish and whales.
Nova Scotia Power customers have a big stake in the outcome of the tests — turbines could provide cheap, clean and abundant electricity in the future.
"We are a province addicted to coal, and this offers a solution to get away from coal over time," Woods said.
Minas Basin has built a $12-million demonstration facility that includes underwater transmission lines to take the power generated by future turbines to a building containing electrical equipment that links up with the Nova Scotia power grid.
The building will also house a research laboratory to help the province and private companies determine whether turbines are environmentally and commercially feasible in the Bay of Fundy.
Lobster fisherman Croyden Wood of Parrsboro believes tidal power will become reality in the Bay of Fundy but he is concerned about how many turbines would be put there.
"We want to put traps down there, and they want to put turbines," Wood said. "I’m afraid if (there are) too many, the fish and lobsters won’t come to the area."
Wood, 47, owns one of the two boats that Minas Basin Pulp and Power hired to take people out on the water to watch Monday’s operation.
After the turbine is eventually retrieved, probably sometime this week, it will be towed to Cherubini Metal Works, a Dartmouth fabrication company.
OpenHydro is picking up the tab for recovering the turbine.
1 comment:
What is the status of this project now? I have been following the hydrokinetic initiative for several years and have been realized that technical realities have not been published. The cumulative impacts are quite startling. We would like to see this turbine when it comes into view to see the condition; i.e., broken blades. The same effect happened in NYC with the Verdant unit. Hydro-kinetic devices might be feasible for small applications.
Normand Laberge, PhD, P.E>
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