TOPIC 'Water Usage' on Mar 06, 2009 (CET)
Nova Scotia Tidal Power
Seventy-percent of Canada’s energy is produced by renewable energy sources. The Bay of Fundy, on the shores of Nova Scotia, has the highest tides in the world. So where better to establish a tidal generator station and capitalize on renewable tidal power?
The Annapolis Royal Generating Station is an 18-MW tidal power plant located on the Annapolis River, upstream from Annapolis Royal, Nova Scotia. Using tidal waters to generate electricity has been a consideration for the Bay of Fundy and its various sub-basins for many years. Essentially, tidal water is captured and released through turbines, generating electric power in the process. The decision to build the Annapolis Royal facility was not entirely environmental or due to conservation. The foundation, causeway, and gateway were in place. The government offered federal funding for this alternative energy project. The foundation needed reinforced and the Department of Transportation required a dilapidated steel truss bridge over the river be replaced.
Generally, the tide comes in, gates open, and the basin fills up in approximately three hours. The upper basin is the power reserve (or battery). The higher the water level the more power will be generated. Gates open and pass liters of water into turbines. Tidal turbines are essentially aquatic versions of open-center wind turbines. About 15 megawatts is generated, depending on size of tide. This translates into approximately 480 cubic meter/second of power. The “used” water flows out other gates back into river.
Water flowing through the turbines produces electricity for about five hours. Methods and technologies are being expanded to increase the tidal power to 24 hours. The generating station has been in operation since 1984. The facility effectively generates electricity, but the dam across the river restricts water flow,
which results in bank erosion. The dam has also trapped marine animals, such as a humpback whale. Due to efficiency and environmental considerations, new technology using submerged tidal stream generators is underway, and expected to be operational in 2010.
Jason Grace
on behalf of the
BascoTec Internet Limited
Technologie Park 13
33100 Paderborn
Germany
