Could the power found in waves be put to good use as a source of renewable energy? Perhaps, but there is still a long way to go before we see any real plans to fully utilise the power contained within waves.
What is wave Energy?
Wave energy is quite distinct from tidal energy, the other potential source of power found at sea. Wave energy involves exploiting the energy which causes buoys to bob up and downwards when at sea. This motion is actually elliptical, and is a constant source of energy for those with the technology to harness it, something mankind has been trying to do for about 150 years. Although some wave energy plants exist these are, for the most part, experimental. With wave energy devices unable to compete with other more reliable and tested counterparts in the renewable energy field, it is likely this will remain the case for some while.
How wave energy works
Most wave energy is harnessed in two ways:
- Large buoys, bobbing up and down on the surface of the sea
- Attenuators allowing waves to flow through the middle of them
Convertors then make this into electricity from where it can be transported to shore. Because wave energy is still in its infancy, a great deal of variety in devices and methods are being tested on each project.
Advantages of wave energy
Wave energy is constant and relatively predictable; even in calm seas it is generally possible to harvest some energy from waves. The volume of energy produced by wave power is also extensive; modern estimates range between 20 and 40MW for some of the largest wave farms. Proper mining of this resource could guarantee the constant flow of energy for countries with large coastlines and high wave volumes.
Disadvantages of wave energy
Wave energy is still in its infancy, with no industry standard on how projects should best exploit this plentiful resource. Those developing wave energy are venturing into the unknown. Some argue - in spite of almost constant research for over 30 years - wave energy has been remarkably unproductive. Great investments in wave energy, therefore, risk being wasted.
Wave energy around the world
The Aguçadoura wave farm in Portugal is the world’s first and, at present, only commercial-scale wave farm. It is located 5km off the country’s coast and totals 2.25MW in installed capacity. However, as if to prove the point about untested technology, it was shut down within two months of opening due to technical problems. The United Kingdom is also investing heavily in wave energy and has plans to build a 20MW wave farm off its South West coast. Although countries in ‘temperate’ bands are well-suited to installing wave farms due to their high wave volumes, few have done so, perhaps due to technological concerns.
Wave energy in Australia
Although there has been little appetite for wave energy in Australia as a whole, some companies have been quick to see the potential benefits. Carnegie Wave Energy LTD, an ASX-listed investor, is the owner of several wave technology patents and has developed a research facility on Garden Island, Western Australia. The ‘Perth energy project’ is currently under construction, but the company hopes to expand operations elsewhere, with sites currently in South Australia, New South Wales and Victoria.
Wave energy certainly has potential to be of use in the future. However, the lack of proven technological capacity means that its utility remains theoretical. Certainly, it is difficult to foresee its usefulness for those interested in investing large sums on it.
Visit our Alternative Energy section for more articles about renewable energy sources.