Tidal Power: Could Waves Provide
10 Percent of America's Electricity?
Dec 08, 2010 - Los Angeles Times
Last month, in the swells off Oahu, a company called
Ocean Power Technologies connected a small test buoy
to the power grid that serves the Marine Corps Base
Hawaii. It was a first for a wave energy device in
"We have demonstrated that our technology works,
that it can survive in harsh ocean conditions and
can deliver high-quality power to the grid," said
Robert Lurie, a vice president of Ocean Power, which
is based in Pennington, N.J.
Next spring, the company plans to anchor a larger
power buoy in the waves off Reedsport, Ore., for
further tests. The ultimate goal, Lurie said, is
to build "multi-buoy wave farms" generating
enough power to light 50,000 homes.
Tapping the tides is the latest niche in the search
for affordable, renewable energy. Widespread use
may be years off, but advocates say tides and other
hydrokinetic systems, from ocean waves to free-flowing
rivers, ultimately could meet up to 10% of America's
electric power needs — more than hydropower
dams now supply.
Pilot projects or studies are underway not only
in Hawaii, but also in Washington's Puget Sound,
in Alaska's Cook Inlet, off Florida, California,
Oregon and Maine, in New York City's East River,
along the Mississippi River and elsewhere.
"These are coastal resources, and most people
live along the coasts," said Hoyt Battey, a
water power expert at the U.S. Energy Department. "When
you're talking about providing half the power of
Alaska or Hawaii, or half the power of New York,
For now, the technology for marine and hydrokinetic
power remains in its infancy, and costs are prohibitive.
Ireland, Denmark, Portugal, South Korea, China, Australia
and other nations have been testing the waters for
years. Commercial operations are rare.
"It's much more difficult to do things underwater
than on dry land," said Robert Thresher, research
fellow at the National Renewable Energy Laboratory
in Golden, Colo. "The water tears stuff apart.
There's fish, rust, fouling … all kinds of
In Washington state, the Snohomish County Public
Utility District plans to install two large turbines
to gather tidal data half a mile offshore and 200
feet deep in Admiralty Inlet in Puget Sound."We
would hope to operate for three years and then make
a decision on whether to expand," said Craig
Collar, project manager.
Canada is investing $75 million for three pilot
projects in the upper Bay of Fundy, home to the world's
highest tides. The first test turbine weighs 400
tons, has a peak capacity of one megawatt and looks
like a sunken windmill.
However, in California, the industry has struggled
to gain a foothold. Last month, Pacific Gas & Electric
Co. suspended a proposed $50-million pilot project
for wave energy near Eureka, citing the difficulty
of obtaining permits and the high cost of development.
"It was a substantial investment for an unproven
technology," said PG&E spokesman Brian Swanson.
He said the utility still was considering a 100-megawatt
project in the ocean off Vandenberg Air Force Base,
near Santa Barbara. "We are very committed to
wave energy," he said.
In theory, the U.S. resource is immense. Waves and
currents are relatively reliable in some areas, and
tides ebb and flood twice a day like clockwork. They
thus are more predictable resources than wind or
Unlike wind, however, tides with sufficient range
and velocity run only in the nation's northeastern
and northwestern corners, mostly Maine and Washington,
plus Alaska. Waves are consistently high only on
the Pacific coast north of Point Conception, Calif.,
and in Hawaii.
Several developments suggest a surge of U.S. interest,
however.The Federal Energy Regulatory Commission
reported this month that it has issued 140 hydrokinetic
preliminary permits for proposals to tap tides, waves
or river currents, up from a handful a few years
ago. In many cases, officials said, applicants are
staking claims in case the technology takes off.
In September, the Energy Department awarded $37
million in matching grants for the first time to
companies with the most promising prototypes or that
appeared close to commercial service.