A new prototype can harvest double the power from ocean waves as previous designs. 

The untapped potential of ocean wave energy is vast - it has been estimated that the power of coastal waves around the world each year is equivalent to annual global electricity production.

With over 35,000 km of coastline, Australia is ideally placed to tap into this power source. Analysis shows Australia could produce twice its current electricity output by harvesting just 17 per cent of its wave energy.

But the challenges of developing technologies that can efficiently extract that natural power and withstand the harsh ocean environment have kept wave energy stuck at experimental stage.

Now, a research team led by RMIT University has created a wave energy converter that is twice as efficient at harvesting power as any similar technologies developed to date.

It relies on a world-first, dual-turbine design.

One of the most popular experimental approaches to harvest wave energy is through a buoy-type converter known as a “point absorber”, which harvests energy from the up and down movement of waves.

But this generally cost-effective design needs to be precisely synchronised with incoming wave movement to efficiently harvest the energy. This usually involves an array of sensors, actuators and control processors, adding complexity to the system that can cause underperformance, as well as reliability and maintenance issues.

The RMIT-created prototype needs no special synching tech, as the device naturally floats up and down with the swell of the wave.

Two turbine wheels, which are stacked on top of each other and rotate in opposite directions, are connected to a generator through shafts and a belt-pulley driven transmission system.

The generator is placed inside a buoy above the waterline to keep it out of corrosive seawater and extend the lifespan of the device.

The prototype has been successfully tested at lab scale and the research team is keen to collaborate with industry partners to test a full-scale model, and work towards commercial viability.

“We know it works in our labs, so the next steps are to scale this technology up and test it in a tank or in real-life ocean conditions,” lead researcher Dr Xu Wang said.

“Tapping into our wave energy resource could not only help us cut carbon emissions and create new green energy jobs, it also has great potential for addressing other environmental problems.

“For example, as the frequency of drought increases, wave energy could be used to power carbon-neutral desalination plants and supply fresh water for the agriculture industry – a smart adaptation to the challenge of a changing climate.”

More details are accessible here.