Maine offers testbed for power from tides
Electricity produced from bay with greatest tide change in continental U.S.
Joel Page / AP
This turbine prototype for a tidal power project is among those tested in Eastport, Maine.
by Jerry Harkavy
updated 4:11 p.m. CT, Thurs., Sept. 11, 2008
EASTPORT, Maine – Workers spent the past winter tinkering with high-tech turbines slung beneath a barge in the cold waters off the Maine coast before getting them to produce a modest 20 kilowatts, enough electricity to power a half-dozen homes.
Far from discouraged, Ocean Renewable Power Co. is spending the summer preparing to deploy larger turbines capable of producing up to 5 megawatts. Or, enough electricity to power 5,000 houses.
Eventually, the company envisions producing enough electricity to power 22,000 homes by harnessing the power of Passamaquoddy Bay, where twice each day the tide rises and falls upward of 20 feet, the greatest tide change in the continental United States.
“This is our beachhead opportunity to enter the market,” project manager John Ferland said.
Even before energy prices surged, a study conducted by the electric utility industry concluded that tidal power could be produced at a cost competitive with wind power and power plants fired by natural gas.
Companies raced to file permits with the Federal Energy Regulation Commission, but Ocean Renewable Power has moved a step forward by using its turbine generating unit to produce power. It is one of dozens of developers positioning for a lead role in tidal power technology.
“Basically, the technology is here. It’s just a matter of engineering it for the lowest cost, the highest reliability and the longest survivability in a hostile and corrosive environment,” said Roger Bedard, who led the study for the Electric Power Research Institute in Palo Alto, Calif.
The experiment taking place in the 120-foot-deep Western Passage represents the latest advance in an emerging technology that seems to be moving forward in baby steps but could one day help meet the growing worldwide demand for clean electricity.
Ocean Renewable Power was the only developer with turbines in U.S. waters that generated electricity this year, Bedard said. He said tests are also being run elsewhere, including the British Isles, Canada and Italy.
As the nation seeks to wean itself from foreign oil and curb global warming, alternative energy sources such as wind, solar and geothermal are becoming more attractive.
Tides hold a number of advantages. Winds can turn calm and clouds can obscure the sun, but the immutable tides turn twice a day no matter what, providing a steady and predictable source of power. Because of water’s greater density, the technology requires fewer turbines to produce the same amount of electricity as wind. And underwater turbines are unlikely to draw complaints about spoiled views or disrupted tranquility from coastal residents.
But tidal power still has a long row to hoe. Bedard figures that tidal is more than 15 years behind wind, which today has an installed capacity of 80,000 megawatts worldwide.
Failed effort during FDR
Eastport was the site of a previous effort to harness the region’s powerful tides, back when Franklin Roosevelt was president and America was mired in the Depression. Down the block from Ocean Renewable Power’s office and across from the tall wooden pilings that expose the magnitude of Eastport’s tides, a museum on Water Street features a scale model of the last effort.
Bob Lewis helped to restore the model, which was built by the Army Corps of Engineers to pinpoint the location of the huge dams and impoundments that were part of Roosevelt’s Passamaquoddy Bay Tidal Power Project.
“It helps put what we’re doing in perspective,” said Lewis, a military retiree who now supervises Ocean Renewable Power’s onsite operations.
