WASHINGTON – Picture 400 super-size windmills spinning in a steady, stiff ocean breeze just beyond the horizon off the Washington coast, generating enough electricity to supply the needs of Seattle and Tacoma.
Now picture thousands of similar windmills off California, New England, the Mid-Atlantic, the Great Lakes and the Gulf of Mexico.
Even as Congress is embroiled in a sharp debate over whether to allow increased offshore oil and gas drilling, others are seriously working to develop a green source of energy along the outer continental shelf.
The winds blowing 15 miles or even farther off the U.S. coast potentially could produce 900,000 megawatts of electricity, or roughly the same amount as the nation’s existing coal, nuclear and gas-fired plants; dams; co-generation; terrestrial windmills; and solar projects combined, according to Department of Energy estimates.
Though the cost of these deep-water, offshore wind farms isn’t firm, some estimate the electricity they would produce could be nearly comparable in price to that generated at today’s power plants. Norway, Denmark, Britain and other European nations are already developing such offshore wind projects.
“This is an energy frontier we are just starting to explore,” said Walter Musial, a senior engineer with the Energy Department’s Wind Technology Center in Colorado. He added that offshore windmill projects in the United States could start appearing between 2012 and 2015.
While some near-shore projects have sparked controversy because the giant windmills could be visible from the coastline, Musial and other engineers and scientists say they are looking at projects mostly at or beyond the horizon.
“This is not a betting man’s game, but the potential is immense, no question about that,” said Burton Hamner, president of Grays Harbor Ocean Energy Co., which has already identified a windmill site about a dozen or so miles off the Washington coast. “On the few days you could see them from shore, they would be about the size of your thumbnail.”
THE BEST WINDS
Offshore winds are generally stronger and blow more consistently than those over land. Land-based wind turbines, like those in Eastern Washington or along the Columbia River Gorge, produce electricity about one-third of the time. A far-offshore wind turbine could operate between 45 percent and 50 percent of the time.
Satellites have been collecting data on offshore wind speeds and directions for a decade. Weather buoys, including the Cape Elizabeth buoy almost 50 miles west of Aberdeen, also track wind speed. Wind speeds at the Cape Elizabeth buoy rarely drop below 20 miles per hour.
The offshore winds along the Northwest coast are among the best in the United States, according to the Department of Energy, which ranks the region’s average ocean breezes as 5 or 6 on a 7-point scale.
Offshore windmills could easily provide enough electricity to meet the demand for all of Western Washington, Hamner said.
Underwater cables would bring the power onshore. About 35 miles of new transmission line would have to be built from Grays Harbor to the site of an abandoned nuclear plant at Satsop, west of Olympia. Before work on the nuclear plant was halted in the early 1980s, a major transmission line was installed that links to the Northwest electric grid.
“It’s a grand vision, and technically it is feasible, but nothing is solid,” Hamner said.
Other industry officials are more skeptical.
“We are aware there are some folks noodling around on this, but it’s not on our drawing boards,” said Terry Oliver, chief technology and innovation officer for the Bonneville Power Administration, the federal power marketing authority that supplies about 45 percent of wholesale electricity in the Northwest.
Jeff King, a senior resource analyst at the Northwest Power and Conservation Council, said far-offshore wind power would not be part of the updated five-year regional energy plan.
“I’m not saying the technology won’t be developed, but deep water is pretty speculative at this point,” King said.
Even so, the idea has its fans.
“This is a slam dunk,” said George Hart, chief technical officer at the Ocean Energy Institute, a Maine-based research center. “None of this is high-tech. It can be done.”
The first offshore units likely will be built off the Mid-Atlantic states, where shallower water presents less of a technological challenge. The continental shelf on the Pacific Coast is much narrower, and deep water is much closer to shore.
But Hamner said he has found a 60-mile long, 30-mile wide shelf in the Pacific stretching north from the mouth of the Columbia River to Long Beach that could be ideal for offshore wind farms. The shelf was formed by sediment caught by northerly currents as it flows out of the Columbia. The water is about 250 feet deep, and windmills could be set on platforms or anchored to the seabed using existing technology.
In deeper water, engineers are designing floating platforms that could hold a windmill. Such floating platforms, attached by cables to weights on the seabed, are already in widespread use in the offshore oil industry.
“The farther offshore, the better the wind,” said George Hagerman, a research faculty member at Virginia Tech’s Advanced Research Institute.
The offshore wind turbines could produce twice as much electricity as those on shore, Hagerman said. The current state-of-the-art terrestrial wind generators can generate 5 megawatts of power – enough to power about 1,500 homes – while some of the offshore wind turbines on the drawing boards could generate 10 megawatts.
“Chances are we will see full-scale prototype units in the next five years,” he said.
IT’S ALWAYS BLOWING SOMEWHERE
The United States has major wind corridors off the West Coast, the East Coast and the Great Lakes and in the plains states from North Dakota to west Texas. If a super-national grid were built, wind energy could be shipped from one end of the country to the other. If the wind wasn’t blowing in one area of the nation, electricity generated from wind power elsewhere could be shipped in from another region.
“The wind will always be blowing somewhere,” said Hart.
The windmills would have to be spaced about two-thirds of a mile apart, and a project with about 200 windmills would cover about 8 square miles and generate 1,000 megawatts, about as much electricity as a nuclear power plant.
The idea is not without a downside. Though the wind farms could be located outside shipping channels, they could interfere with such migrating species as gray whales or seabirds, and with fishing and crabbing.
One large offshore wind farm is already planned in British Columbia’s Queen Charlotte Islands. It could produce about 700 megawatts of electricity, or enough to power about 210,000 homes.
Hamner’s company has received a preliminary permit from the Federal Energy Regulatory Commission to begin developing a small wave energy project about three miles off the coast near Grays Harbor. The company is discussing with local officials the possibility of temporarily placing a windmill on one of the platforms as a demonstration project.
“We hope it might become a beachhead for a larger wind project,” he said.
Les Blumenthal: 202-383-0008