Want clean energy? Give us a wave

Australians all let us rejoice because our national anthem may hold the answer to our renewable energy prayers. I’m not talking about our golden soils or our rich and rare beauty, I’m more interested in the fourth line of the song – Our home is girt by sea.

The ocean. We are lucky enough to be completely surrounded by it. While most may think of the ocean as a place for fun and relaxation, it’s rarely mentioned for its energy producing potential. Instead, a lot is made of our abundant wind and solar resources (and rightly so). But should we be thinking more seriously about our unrivalled access to energy from the sea?

There’s no shortage of coastline in Australia. Image: WANG-HSIN PEI via Flickr

Energy from waves

It’s waves, the motion in the ocean if you will, which present the opportunity for clean energy production.

It can be argued that wave power can provide a more consistent power source than wind and solar. Solar doesn’t work when the sun goes down, which is a shame considering that daily phenomenon we call night time. And guess what? When the wind ain’t blowing, the power ain’t flowing (I’m sorry).

Waves on the other hand are remarkably consistent, particularly in parts of southern Australia. Because of regular strong winds, the Southern Ocean produces large waves pretty much 24/7 making it an ideal location to harness wave energy. ARENA’s wave atlas provides a clear indication of this potential.

How does it work?

There are different methods of harnessing the energy of waves. One of which, Carnegie Clean Energy’s CETO 6 technology deserves a special mention.

Carnegie Clean Energy’s CETO technology. Image via Wikimedia Commons

This technology involves an array of fully submerged buoys, which are anchored to the ocean floor and move up and down with the passing waves. This movement is captured and used to pump high pressure water on shore to hydro-electric turbines which produce electricity. The beauty here is that the electricity producing turbines are mature, off-the-shelf technology meaning fewer teething problems than entirely new devices.

Recently, my home town of Albany in Western Australia announced a pilot wave energy project using CETO 6. Carnegie will install a 1MW demonstration plant off the coast, in sight of the city’s 18 turbine wind farm. In the long run, Carnegie hopes to expand the facility to a massive 100MW.

The benefits of CETO 6 don’t end with producing clean, zero emissions electricity. The power generated is used, in the same facility, to desalinate sea water and provide fresh drinking water. In places like Albany this aspect of CETO 6 is extremely valuable considering the region’s water supplies are already strained under the pressure of a drying climate.

Waves off the coast of Albany will soon be used to generate electricity. Image: Mark Pegrum, via Flickr

Are waves the answer?

In theory, wave power looks to be a perfect fit for Australia – we are surrounded by oceans, our major cities are on the coast and 85% of our population live within 50km of the water.

However, in reality, the technology still needs time and investment to develop. It is currently financially uncompetitive when compared to wind and solar. The small pilot project in Albany for example, is conditional on a $15.7 million state government grant. The costs must come down before it is considered commercially viable on a large scale.

Despite this, the CSIRO suggest wave power could contribute up to 11% of Australia’s total energy mix by 2050. This number is far from insignificant, representing enough electricity to power all of Melbourne.

Overall, the fate of innovative wave energy projects like Albany’s – whether they wipe-out or score a perfect 10 – will determine how much of our future will be powered by the ocean’s waves.

2 Responses to “Want clean energy? Give us a wave”

  1. awylde says:

    Thanks Rob. It’s good to know my pun did not go unappreciated!
    I believe there are other types of wave energy technologies out there (like this one in Port Fairy) but CETO is specific to Carnegie. It has already been trialled off Garden Island near Perth and seems to be quite promising.
    I’m referring to the hydro-electric turbines when I say “off-the shelf”. That technology is quite mature so I’d imagine maintenance would be a breeze. As for the CETO buoys I’d would expect it to be a bit more difficult and expensive to fix if anything went wrong.

  2. Rob Dabal says:

    Full marks for your pun.

    An interesting technology, has it been trialled elsewhere in the world? I have a vague recollection of hearing about this technology many years ago. I didn’t delve too much in the links you included but can you tell us how long the technology has been around? If the engineering is ‘off-the-shelf technology’ is the cost of maintenance prohibitive?

    Understanding motion in the ocean deserves further promotion and devotion!