Researchers predict tidal turbines are the wave of future energy
The next wave of environmentally friendly power is being developed in the world’s oceans and tidal basins.
Researchers hope wave farms and tidal turbines will be generating power from either the motion of the waves or from inshore tidal currents anywhere from three to 15 years from today.
“ This technology is as real today as wind energy was in 1980,” says George Hagerman, a senior research associate at Virginia Tech’s Centre for Energy and the Global Environment.
Water power technology is in its infancy, but a number of demonstration projects are already underway.
Off the British Columbia coast near Victoria, Calgary’s EnCana Corp. has partnered with the Lester B. Pearson College of the Pacific and a small tidal turbine company, Clean Current Power Systems, to test a 65- kilowatt tidal turbine generator.
On Canada’s East Coast, Nova Scotia and New Brunswick have joined forces with five American states to commission a $425,000 feasibility study on tidal turbine viability.
Greg Carlin, a senior engineer with Nova Scotia Power, maintains that if tidal turbine energy were fully developed it could provide as much as 40 per cent of the total provincial need.
Between them, Nova Scotia and New Brunswick have identified 20 sites where the turbines might be placed, including locations in the Bay of Fundy, the Cumberland Basin and the Minas Basin.
“It may work,” Carlin said. “It all comes down to what it costs in the end.”
Wave farms and tidal turbines are often bizarre looking contraptions. They range from Denmark’s prototype Wave Dragon, in which wave surges drain down into a turbine, to Energetech’s offshore turbine, which resembles a small floating factory and uses a parabolic wall and chamber to capture as much of a wave’s energy as possible.
The Pelamis wave farm off Portugal’s coast looks like a broken pencil floating on the water’s surface.
The Pelamis tries to follow the contour of the wave passing over it. As the water crests the device, it causes joints in the Pelamis to flex, stoking piston pumps that power a hydraulic motor. That in turn powers a generator.
Hagerman likens the development of water energy to the beginning of wind energy, pointing out that in the beginning the latter tested many different formats before arriving at the best, most cost- efficient design. No such prototype has been developed to date.
Even so, two projects are already feeding power to utility gr i d s , o n e of wh i c h i s t h e Pelamis. The other, also off the coa s t o f Po r t u ga l , i s t h e Archimedes wave swi n g . Deployed in 2004, the wave swing has a floater that heaves up and down in response to the movement of waves overhead, powering magnets along a coil to produce electricity.
Before water power becomes commercially viable on a wide scale, many challenges stand in the way.
While most water energy advocates insist the new technology is benign, they also agree any location for the wave farms or tidal turbines would require consultation with everyone from fishermen to marine transport agencies.
Materials must be carefully chosen to withstand the corrosive effects of salt water, and concerns exist over everything from the noise from the gear boxes for the turbines to the use of oils and other substances in the machinery.
The largest hurdle is funding.
“ Unfortunately, all of these projects are extremely capital intensive. In other words, we’re not building washing machines.
“ We’re building very large physical devices,” says Cynthia Rudge.
Rudge, an Ontario- based development consultant for two tidal turbine companies, Energetech and the United Kingdom’s Lunar Energy, says while the hunt for money for new technology is always difficult, Energetech has raised about $17 million.
“ It ’ s the early stage of an emerging industry, which I think the public will support when it’s clear it produces green energy with relatively minor environmental impacts,” Rudge says.
For CanWest News Service