- Undaunted by past failures, a new wave of entrepreneurs
is seeking to generate electricity by channeling the energy of the Earth's
oceans.
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- In experiments from Southern Australia to Scotland to
Northern California, startup energy firms and researchers will be testing
a host of technologies in the coming months aimed at generating electricity
from the sea.
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- Among the most ambitious, planned for this fall, is a
486-ton wave turbine that converts wave motion into electricity and will
be anchored off the coast of Australia, 150 miles south of Sydney. Energetech,
the Australian company that developed the turbine, said it will be the
"first plant in the world to make wave energy commercially viable."
A similar turbine is to be installed off Point Judith, Rhode Island, in
2006.
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- Escalating oil prices and worries about global warming
have shifted the quest for renewable energy sources into high gear. While
wind and solar claim most of the attention, and hopes are high for high-tech
hydrogen, the dark horse in this race may be the restless energy of the
sea.
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- Covering 71 percent of the Earth's surface, the oceans
are in essence the world's largest collector of energy from the sun. According
to the Department of Energy, waves could generate 2 terawatts of electricity
-- enough to meet the world's current electricity needs. Energy embodied
in the world's ocean currents and tides is twice that much. However, only
a small percentage of this could be tapped and thus far efforts to do so
have cost more than the energy they've generated.
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- Energetech has made significant improvements on previous
efforts, said Alison Cornish, the company's business services manager.
Its 115-foot-wide turbine directs a wide wave front into a chamber by means
of a parabolic shaped opening. The rising and falling motion of the waves
pushes a powerful jet of water inside the narrow chamber, much like a blowhole.
That, in turn, forces a high-speed airflow past a controllable turbine
that spins in the same direction no matter whether the air is coming in
or going out.
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- Tom Denniss, the inventor and Energetech's CEO, has been
working on this since 1991. Over that time a number of wave turbine prototypes
by other companies in Denmark, Scotland and elsewhere have either broken
down or been commercial failures. But with countries looking to reduce
their carbon emissions, there's still a great deal of interest. In fact
Energetech's Rhode Island project is partially funded by the Connecticut
Clean Energy Fund.
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- Like most other renewable sources, wave generators can't
store energy and the cost of building structures is high.
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- "It's a bit of (a) scientist's dream at this point,"
said Elena Nekhaev, director of programs at the World Energy Council.
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- Dream or not, there are a number of wave and tidal energy
projects currently underway. At least two new wave-energy power plants
are being tested in Scotland, which is also home to the newly established
European Marine Energy Center. This month, the British government also
said it would invest $85 million to develop the technology.
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- Independent Natural Resources, a Minnesota energy engineering
company, wants to install its Seadog wave turbine off the coast of Humboldt
County in Northern California. The Seadog uses wave action to pump seawater
to an elevated reservoir onshore. Water from the reservoir is then released
down a flume to turn an onshore turbine.
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- The Seadog offers the advantage of being able to store
some energy as water in the reservoir. When more electricity is needed,
more water is released down the flume. The first trial pump is expected
to be installed by the end of the year. If it succeeds, a 16-pump project
will follow, producing enough power to service about 600 homes.
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- In September, New York City will receive some of its
electricity from six underwater turbines attached to concrete piles in
the East River that will be powered by the tides. Although only generating
enough power for about 200 homes, this will be the first tidal-turbine
power plant in the world. Virginia-based Verdant Power, the company overseeing
the project, said if all goes well 200 to 300 turbines will be installed.
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- One of the toughest tests for wave and tidal power plants
is surviving the continual pounding, storms and all that salt, said Rick
Mercier, director of the Offshore Technology Research Center. "The
seas pose a severe challenge to any equipment over the long term,"
Mercier said.
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- OTRC normally tests offshore oil and gas-drilling rigs
but has recently been testing wave-power plants like the Seadog.
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- "Building something that will last can drive up
the costs," Mercier said. In other words, building a wave power plant
that could last 30 years is doable. But whether it's cost-effective is
unknown.
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- In the meantime, government investments are still needed
to make renewable energy competitive with oil and gas, said Nekhaev of
the World Energy Council.
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- "There have been no breakthroughs in wave and tidal
energy," she said. "Just refinements."
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