MELBOURNE — A new study by the CSIRO (the Commonwealth Scientific and Industrial Research Organization), revealed that Australia’s oceans could supply 10 percent of the country’s electricity by 2050. This is the equivalent of powering a city the size of Melbourne, which has a population of around four million.
The Australian science agency study investigated the potential of harnessing the energy of the oceans — from waves, tides, currents and thermal energy — to power the country’s electricity from 2015 to 2050.
Their report, Ocean Renewable Energy: 2015-2050, showed that there are tremendous energy resources in Australia’s southern oceans, in particular near the west coast of Tasmania, the southern ocean in Victoria, and the south-west ocean of Western Australia.
This is the first time in Australia that ocean-based renewable energy has been assessed from resource to market development. Dr Susan Wijffels, a spokesperson for the CSIRO, said that the findings showed that wave power could be integral to Australia’s renewable energy plan.
“The idea [of ocean power] has been around for a very long time,” Dr Wijffels said. “It’s getting attention now because some countries are currently looking at how viable some of these technologies are. I suspect it has to do with the policy setting in an energy market.”
There are at least 200 wave energy converter (WEC) devices that extract the energy from either the surface motion of the waves or the pressure fluctuations below the surface. The range of this energy capture varies between devices and to differing degree of success. Some companies are currently conducting pilot tests and commercial demonstrations.
There are three main classes of WEC devices that can be loaded in various depths: Point absorber (a float that is free to follow the movement of the wave and gather wave energy from any direction); linear attenuator (a float aligned in the direction of the wave); and terminator (a device that faces the wave directly to collect the energy).
The fact that around 80 percent of Australia’s population live in coastal areas, suggests that wave power will play a very significant part in the country’s energy future.
Dr Wijffels claims that wave power holds many key advantages over solar and wind power, including its consistency (waves are generated both day and night), and predictability as an energy resource.
Solar and wind are subjected to sudden changes in weather, whereas wave power comes from the momentum of an ocean storm that can often take days to reach our shores.
“If you get a longer lead time, then you know that wave plant will give you power. The people that manage our electricity supply in the future will want to know when and how much renewable energy is coming in and how it will fit in to the grid,” she said.
“The other big challenge we have is getting the grid ready. How to shift power across the country very cheaply, quickly and in large volumes,” Dr Wijffels said.
She contends that the technology has the potential to be cost-effective, but this will largely be dependent on overcoming engineering challenges such as creating efficient energy farms and harvesters.
“Water is really heavy. When water is moving, it gets moved by either tidal forces or waves, and that’s a lot of momentum. The energy density, as a resource, is much higher than wind. If we can get the turbines to work efficiency, we’re using less real estate for more power. If we can build really efficient extractors that can be made cheap enough to maintain, then that advantage could be realised,” she says.
The CSIRO are careful to point out that there are many economic, technological, environmental and societal challenges that will determine wave energy’s place in Australia’s future energy mix. These include investigating the wider impacts of the technology as it relates to issues such as as marine life and aquaculture.
The CSIRO hopes that their report will encourage the renewable energy industry, government and the public to think seriously about the opportunities, as well as the challenges, for ocean technology in Australia.
Photo: WHL Travel/Flickr