Catching the next wave in renewables

CSIRO recently announced that energy from the ocean could supply 11 per cent of Australia’s demand by 2050. That is enough to power a city the size of Melbourne.

It is a bold claim, but it’s time for Australia to look at the sea differently.

The World Energy Council recognised the potential several years ago when it listed Australia’s southern coastline as one of the world’s best sources of wave energy.

Predictability and power are what make the ocean competitive with wind as a power source. It also makes it the new frontier for renewable energy exploration.

The federal government has set a target of 20 per cent renewable electricity generation by 2020. CSIRO modelling shows the potential for ocean energy to make up a significant part of this figure.

Our investigation used engineers, oceanographers and economists to review what devices are being developed, trialled and commercialised around the world. We consulted with Australian companies already working in this area of exploration, and examined potential environmental and social impacts.

What types of ocean energy are there?

Tidal energy is where the sun and moon pulls at the ocean and fills bays and estuaries every day. Placing tidal turbines individually or in a row would take advantage of these vast water movements. Likely sites include northern and western regions and the Banks Strait off the east coast of Tasmania.

Ocean thermal energy uses the temperature difference between the surface and deep ocean. This disparity can be used to condense and vaporise a working fluid to drive a turbine. A prime location would be off the Queensland coast which has a differential of about 10 degrees between surface and abyss.

There are deep water currents in the ocean which might be captured using enormous turbines anchored to the sea floor. Such currents exist off the east coast.

There are also thousands of kilometres of coastline in Australia where waves dump the concentrated energy of the ocean.

And it is this – wave energy – which holds the greatest potential for Australia.