Canada harnesses power of tides
By Elizabeth Blunt
BBC World Service correspondent, Canada
The world's highest tides are a source of electricity for Canada
The one thing that every schoolchild learns about the Bay of Fundy is that it has the highest tides in the world.
The North Atlantic waters are funnelled up this deep inlet between the Canadian provinces of New Brunswick and Nova Scotia, swirling through the narrowest parts of the bay with impressive speed and power.
So when in the 1980s the Canadian government wanted to explore the feasibility of tidal power, this was a natural site for an experimental station.
The site chosen at Annapolis Royal had already been closed off by a causeway, built to control tidal flow further up the Annapolis River.
The idea was that water flowing through the sluices could also pass through a turbine and generate power on its way down the Bay of Fundy and out into the sea.
Now there is a neat box-like structure in the middle of the causeway, one of only a handful of operational tidal power plants in the world.
Plant engineering
The Bay of Fundy funnels the power of the Atlantic
Twice every day, as the tide rises, the sluice gates are opened to let water flow up into the lower part of the Annapolis river, which now serves as the headpond for the power station.
Just before high tide, the gates are closed, leaving only a narrow passage for fish to pass. Now all the operators have to do is wait for the tide to turn and the water level on the seaward side to drop.
When there is enough difference between the water levels on the two sides, they begin to let water flow through the giant turbine, slowly at first to get it turning, and then at full strength.
Once the huge 25-metre diameter wheel is up to its operating speed of 50 revolutions per minute, the station starts to generate. At peak power it supplies a very respectable 20 megawatts to the Canadian grid.
Once the tide has gone out and the water level is equalised, the turbine slows to a stop, before the whole cycle begins again.
Stuart MacDonald of Nova Scotia Power remembers the thrill of seeing the plant in action for the first time. He loves the elegant simplicity of its engineering and its reliability, but accepts that tidal power has its limitations.
Built for purpose
It may be a predictable source of electricity, but only while the tide is going out.
Water flows through a giant turbine at Annapolis Royal
And it is not the sort of thing that can be bought off the shelf; machinery has to be purpose-built for the site, which makes it expensive for a power station which is always going to be idle for at least 12 hours a day.
But at least the fuel is free; and although the plant was designed for a 70 year lifespan, Stuart MacDonald believes that with proper maintenance it could last 200 years.
The technology, though, has yet to take off in a significant way.
The biggest tidal station in world is in France, near St Malo, 12 times larger than Annapolis Royal; Russia has a much smaller plant, while China has constructed several small facilities.
With fossil fuels getting scarce and expensive, and concern rising about the damage they are causing to the atmosphere, interest in tidal power is growing; because these plants produce no greenhouse gas emissions.
Other projects are planned, and designers are now working on plans involving individual turbines moored in the middle of the tidal flow, easier to build and less environmentally controversial than the fixed barrages used by the existing stations.
Friday, April 15, 2011
Tidal Power
Partnerships to develop Islands’ tides
Testing a five-kilowatt turbine last November in the Bay of Fundy. Published on April 14, 2011
John DeMings Fundy Tidal to apply for feed-in tariff for power projects
Fundy Tidal Inc., a community-based marine energy developer, has entered into two separate agreements to develop in-stream tidal power in the waters of Digby Neck and Islands.
Topics : New Energy Corporation , Grand Passage , Ocean Renewable Power Company of Maine , Digby County , Petit Passage , Long Island
A news released from Fundy Tidal said it and Alberta-based New Energy Corporation Inc. will install and operate several tidal turbines in the swift currents of Grand Passage between Brier and Long islands.
The plan is to use New Energy’s 250-kilowatt ‘EnCurrent’ generation system, a vertical-axis in-stream hydrokinetic turbine.
Fundy Tidal has also entered into a partnership with Ocean Renewable Power Company of Maine to install its ‘TidGen’ power system in Petit Passage between Digby Neck and Long Island.
Fundy Tidal says analysis of final site locations will be completed this year, and a single unit will then be installed next year. The projects will then add further turbines with a goal of producing two to five megawatts.
The projects are subject to satisfying all regulatory requirements and support from community stakeholders.
The province’s recently enacted Renewable Electricity Plan has established community feed-in tariffs (COMFIT) for 100 megawatts of wind energy, combined heat and power, run-of-river hydro and small-scale in-stream tidal projects in Nova Scotia.
Eligible projects under the COMFIT must be majority owned by community proponents, including a minimum of 25 persons from the community.
Utility and Review Board rate hearings began April 4 in Halifax to finalize COMFIT rates for wind, combined heat and power, run-of-river hydro and small-scale in-stream tidal.
A statement from Fundy Tidal said the province expects the application process to begin soon after for submissions from eligible proponents which include municipalities, First Nations, universities, non-profits, and co-ops and community economic development corporations.
The town and municipality of Digby, for instance, have been looking at erecting a wind turbine and selling power to effectively reduce their joint electrical bills.
Westport village commissioner and Fundy Tidal founder Jim Outhouse said many years of hard work have promoted Digby County as the ideal location to create tidal power and to establish a thriving research and development community and industry hub.
“We have made our living from these waters for generations, and with the downturn of the fishery, we see this new industry as a means to return to more prosperous days and attract new families, businesses and jobs to the region.”
The Petit and Grand passages were identified by the Electronic Power Research Institute as a primary location for development of tidal energy, and resulted in the formation of Fundy Tidal in 2006.
Fundy Tidal president Dana Morin says the creation of a feed-in tariff for tidal power and one that requires community ownership are world firsts. Combined with tidal developments in Minas Passage, the province has solidified its position as the place to demonstrate both large and small-scale devices and connect to the grid with a guaranteed rate.
“Digby County will play a key role not only as a source of green energy production but in providing the infrastructure and expertise required to support and grow the tidal industry in region,” he said.
Testing a five-kilowatt turbine last November in the Bay of Fundy. Published on April 14, 2011
John DeMings Fundy Tidal to apply for feed-in tariff for power projects
Fundy Tidal Inc., a community-based marine energy developer, has entered into two separate agreements to develop in-stream tidal power in the waters of Digby Neck and Islands.
Topics : New Energy Corporation , Grand Passage , Ocean Renewable Power Company of Maine , Digby County , Petit Passage , Long Island
A news released from Fundy Tidal said it and Alberta-based New Energy Corporation Inc. will install and operate several tidal turbines in the swift currents of Grand Passage between Brier and Long islands.
The plan is to use New Energy’s 250-kilowatt ‘EnCurrent’ generation system, a vertical-axis in-stream hydrokinetic turbine.
Fundy Tidal has also entered into a partnership with Ocean Renewable Power Company of Maine to install its ‘TidGen’ power system in Petit Passage between Digby Neck and Long Island.
Fundy Tidal says analysis of final site locations will be completed this year, and a single unit will then be installed next year. The projects will then add further turbines with a goal of producing two to five megawatts.
The projects are subject to satisfying all regulatory requirements and support from community stakeholders.
The province’s recently enacted Renewable Electricity Plan has established community feed-in tariffs (COMFIT) for 100 megawatts of wind energy, combined heat and power, run-of-river hydro and small-scale in-stream tidal projects in Nova Scotia.
Eligible projects under the COMFIT must be majority owned by community proponents, including a minimum of 25 persons from the community.
Utility and Review Board rate hearings began April 4 in Halifax to finalize COMFIT rates for wind, combined heat and power, run-of-river hydro and small-scale in-stream tidal.
A statement from Fundy Tidal said the province expects the application process to begin soon after for submissions from eligible proponents which include municipalities, First Nations, universities, non-profits, and co-ops and community economic development corporations.
The town and municipality of Digby, for instance, have been looking at erecting a wind turbine and selling power to effectively reduce their joint electrical bills.
Westport village commissioner and Fundy Tidal founder Jim Outhouse said many years of hard work have promoted Digby County as the ideal location to create tidal power and to establish a thriving research and development community and industry hub.
“We have made our living from these waters for generations, and with the downturn of the fishery, we see this new industry as a means to return to more prosperous days and attract new families, businesses and jobs to the region.”
The Petit and Grand passages were identified by the Electronic Power Research Institute as a primary location for development of tidal energy, and resulted in the formation of Fundy Tidal in 2006.
Fundy Tidal president Dana Morin says the creation of a feed-in tariff for tidal power and one that requires community ownership are world firsts. Combined with tidal developments in Minas Passage, the province has solidified its position as the place to demonstrate both large and small-scale devices and connect to the grid with a guaranteed rate.
“Digby County will play a key role not only as a source of green energy production but in providing the infrastructure and expertise required to support and grow the tidal industry in region,” he said.
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