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The Leading Edge

Two tidal projects proposed off coast of Maine

The city of Eastport, Maine, and tidal power developer ORPC Maine LLC are pursuing development of two tidal projects off the coast of Maine, 18.96-MW Western Passage OCGen Power and 23.7-MW Cobscook Bay OCGen Power. The projects will use ORPC’s Ocean Current Generation (OCGen) technology.

ORPC applied for preliminary permits from the Federal Energy Regulatory Commission (FERC) to study the projects.

ORPC plans to initially install a full-scale prototype system in the Western Passage. The Western Passage divides the U.S. state of Maine from the Canadian province of New Brunswick. This system would cost about $6 million and be installed in early 2009. ORPC then plans to conduct at least a year of testing and monitoring.

Upon receipt of the required licenses from FERC, the developer plans to build commercial-scale tidal projects at both sites, with an estimated capacity of 10 MW. Both projects will be connected to the electrical grid through Bangor Hydro.

In return for Eastport’s support of the development effort, ORPC is to maximize the amount of work that can be performed locally, identify economic benefits to Eastport, and provide public education on ORPC and its projects.

ORPC is using a $300,000 development award from the Maine Technology Institute to support the commercial development of power from tidal energy. The award is to be used for the detailed engineering of a prototype project, testing, and eventual installation of a full-scale commercial project.

ORPC Maine is a unit of Ocean Renewable Power Co. LLC of North Miami, Fla.

Assessing the future ofocean energy in Canada

The National Energy Board (NEB) of Canada says there are 55 potential sites for tidal energy projects near Vancouver Island in the province of British Columbia. These sites are distinguished by current speeds greater than 2 meters per second. Twelve of the 55 sites have the potential for 10 MW of generation each.

NEB defines tidal energy projects as those that use the head created between the water levels in the ocean at high and low tide to generate electricity.

Currently, there is only one operating tidal project in Canada – a 20-MW installation in Annapolis Royal, Nova Scotia.

Energy from tidal projects is easier to integrate into the grid than that supplied by wave energy facilities, NEB says. Energy from either type of project is intermittent, but the daily cycle of tides and tidal currents is fairly predictable. However, the cyclic availability of this energy requires some form of backup, storage, or synergy with other power sources, NEB says.

Several organizations in Canada are conducting research to develop ocean energy technology. These include the National Research Council at the Institute of Ocean Technology in Newfoundland, Powertech (a subsidiary of BC Hydro), the University of Victoria, and the University of British Columbia.

– An assessment of ocean energy in Canada is available as part of the Emerging Technologies in Electricity Generation report. To read or print this report, visit: www.neb-one.gc.ca/ energy/EnergyReports/EMAEmergingTechnologiesElectricity2006_e.pdf.

Hydro-Québec using hydroto integrate wind generation

Hydro-Québec Generation is using a portion of its hydropower capacity to provide wind power integration services to Hydro-Québec Distribution, the electricity distributor in the province of Québec. This integration service requires both balancing of the intermittent nature of wind generation and a guarantee to replace the wind generation capacity with production from hydroelectric facilities when necessary.

To balance wind power, Hydro-Québec’s production division adjusts hourly output from the hydroelectric units to absorb the effect of the hourly variations in wind energy delivered to the system. To help make these adjustments, the production division uses a wind power generation forecast for the following day.

To establish the cost of this balancing service, the utility determines differences between forecast deliveries for each hour and the actual quantity of wind energy delivered each hour, says Luc Bernier of Hydro-Québec. The utility then calculates the absolute value of the daily sum of these hourly differences. This result is multiplied by C$0.001 per kilowatt-hour.

The utility also guarantees capacity equivalent to 35 percent of the contract capacity of the wind resources. This equals the capacity factor of the wind farms providing energy to Hydro-Québec. With the utility’s current wind capacity at 990 MW, this equates to 347 MW. The utility has a total hydro capacity of 37,440 MW.

The price for this capacity for wind integration purposes, set as part of the original agreement between the generation and distribution departments, is C$80 per kilowatt-year. This price applies to the difference between the guaranteed capacity and the wind farms’ actual capacity contribution.

Hydro-Québec estimates that the total cost of this integration service is C$0.005 per kilowatt-hour.

EPRI releases report on Alaskawave and tidal potential

Fourteen sites in the ocean off southeast Alaska have total generating potential of more than 2,750 MW, according to a report published by EPRI. The report, Tidal In-Stream Energy Resource Assessment for Southeast Alaska, was prepared at the request of the Alaska Energy Authority. The purpose was to determine the magnitude of the available in-stream resource in six specific locations.

EPRI evaluated the sites using four criteria:

 

The site with the greatest cross-sectional area is North Inian Pass in Cross Sound. This site also has the highest average depth (230 meters) and the most power potential (1,600 MW). The site with the greatest power density is Kootznahoo Inlet in Chatham Strait, with a density of 7.4 kW per square meter.

EPRI suggests the next steps in the ongoing process of site development in southeast Alaska should be to perform a site feasibility and economic assessment and to conduct a more detailed resource study, including numerical calculations and field measurements.

Of the sites investigated, EPRI concludes that only those in Cross Sound and Icy Strait are suitable for development of large-scale power plants. In fact, EPRI indicates the potential in these areas is more than enough to meet the region’s energy needs and to allow export of electricity to Canada and the Pacific Northwest. However, the other sites studied may be good options for providing electricity in remote locations, especially those sites with strong power density.

– To print this report, visit the Internet: www.epri.com/oceanenergy/ streamenergy.html#reports and click on TP-003 AK.

Snohomish County PUDstudying seven tidal projects

Snohomish County Public Utility District (PUD) No. 1 in Washington is studying sites for seven proposed tidal energy projects. These projects will be located in Puget Sound and could have a total capacity of 47.6 MW.

The studies include: defining and documenting actual tidal conditions, investigating each site’s bathymetry and geotechnical attributes, considering potential tidal devices, assessing project economics, considering multi-use issues and concerns, investigating environmental effects and mitigation strategies, and determining how to best connect the energy source to the grid.

The PUD plans to work with several partners during the study phase, which could take as long as three years. Partners include the University of Washington, EPRI, and Bonneville Power Administration. Snohomish County PUD also plans to seek comments from local tribes, environmental groups, and other organizations.

In February and March 2007, the Federal Energy Regulatory Commission (FERC) issued preliminary permits for the seven projects:

 

Preliminary permits give Snohomish County PUD permission to study the projects’ economic and environmental feasibility.

Florida establishing center tostudy ocean energy technology

Florida Atlantic University is establishing the Florida Center of Excellence in Ocean Energy Technology. One focus of the center is to study the possibility of using the Gulf Stream as a renewable energy source.

Work at the center will involve research, design, development, implementation, testing, and commercialization of ocean energy technologies that are cost-competitive with existing power technologies, says Dr. Rick Driscoll, associate professor in the university’s department of ocean engineering.

To establish the center, Florida Atlantic University will work with Florida Power & Light, the U.S. Department of Energy, the National Renewable Energy Laboratory, Ocean Renewable Power, the U.S. Navy, Lockheed Martin, Clipper Windpower, Oceaneering, Aquantis, the University of Central Florida, Nova Southeastern University, and Harbor Branch Oceanographic Institution.

The Florida Technology, Research and Scholarship Board contributed $5 million for the center.


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