Chinese-Australian researchers extract twice the power from ocean waves with new prototype

A research team led by RMIT University has developed a wave energy converter said to be twice as efficient at harvesting power as any similar technologies developed to date.

The wave energy innovation (pictured), published in the journal Applied Energy, relies on a dual-turbine design, claimed to be a world-first by RMIT engineers who worked in collaboration with researchers from Beihang University in China to develop the new technology.

The RMIT-created prototype needs no special synching tech, as the device naturally floats up and down with the swell of the wave, as opposed to the more traditional types of wave energy devices such as point absorbers which need to be precisely synchronized with incoming wave movement to efficiently harvest the energy, adding complexity to the overall system.

Lead researcher Xu Wang said wave energy was one of the most promising sources of clean, reliable and renewable power.

“Our prototype technology overcomes some of the key technical challenges that have been holding back the wave energy industry from large-scale deployment. With further development, we hope this technology could be the foundation for a thriving new renewable energy industry delivering massive environmental and economic benefits”, Wang said.

The technology consists of two turbine wheels, stacked on top of each other and rotating in opposite directions, which 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.

“By always staying in sync with the movement of the waves, we can maximise the energy that’s harvested. Combined with our unique counter-rotating dual turbine wheels, this prototype can double the output power harvested from ocean waves, compared with other experimental point absorber technologies”, Wang added.

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, according to the RMIT University.

“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.

“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”, Wang concluded.

The research was supported through an Australian Research Council (ARC) Discovery Project grant.