Dozens
of wave-energy technologies are being developed around the world:
ideas, in other words, are not what has held the field back. So what
has?
Tom Thorpe of Oxford Oceanics, a consultancy,
blames several overlapping causes. For a start, wave energy has lagged
behind wind and solar, because the technology is much younger and still
faces some big technical obstacles. The British government’s decision
to shut its wave-energy research program, which had been the world’s
biggest during the 1970s, set the field back nearly two decades. Since
Britain is particularly well placed to exploit wave energy its decision
not to pursue the technology affected wave-energy research everywhere.
Once
interest in wave power revived earlier this decade, practical problems
arose. A recurring problem, ironically enough, is that new devices
underestimate the power of the sea, and are unable to withstand its
assault. Installing wave-energy devices is also expensive; special
vessels are needed to tow equipment out to sea, and it can be difficult
to get hold of them.
Another practical problem is the lack of
infrastructure to connect wave-energy generators to the power grid. The
cost of establishing this infrastructure makes small-scale wave-energy
generation and testing unfeasible; but large-scale projects are hugely
expensive.
But at last there are signs of change. Big utilities
are taking the technology seriously, and are teaming up with
wave-energy companies. The Economist looks at several technologies in
varying stages of commercialization.
Several buoy-based systems are in developmennt, inlcuding the Aquabuoy, designed by Finavera Renewables of Vancouver
[CVE:WND] which Pacific Gas & Electric hopes to deploy off the
California coast. Similar bobbing buoys are also being worked on by AWS Ocean Energy, based in Scotland, and Ocean Power Technologies (OPTT), based in Pennington, New Jersey, among others.
The Oyster, a wave-power device from Aquamarine Power,
another Scottish firm, works in an entirely different way. The
generator is onshore, and can be connected to lots of Oyster devices,
each of which is expected to generate up to 600kW. The idea is to make
the parts that go in the sea simple and robust, and to keep the
complicated and delicate bits out of the water. Testing of a prototype
off the Orkney coast is due to start this summer.
The logical conclusion of this is to put everything onshore—and that is the idea behind the Limpet. It is the work of Wavegen, a Scottish firm which is a subsidiary of Voith Siemens Hydro, a German hydropower firm. A prototype has been in action on the island of Islay, off the Scottish coast, since 2000.
Venture-capitalists
are piling in too, as they look for new opportunities. Several
wave-energy companies are thought to be planning stockmarket flotations
in the coming months.
