Researchers developed a prototype that can double the power harvested from ocean waves as compared to existing technologies.
Engineers across the world have tried to harvest energy from ocean waves. Ocean currents can be potential sources of energy, but the harvesters that can efficiently extract that natural power and withstand the harsh ocean environment have kept wave energy stuck at experimental stage.
To make wave energy a viable renewable energy source, researchers from RMIT University have developed a prototype that can double the power harvested from ocean waves as compared to existing technologies. Their work has been published in the journal Applied Energy.
Lead researcher Professor Xu Wang said, “While wind and solar dominate the renewable market, they are available only 20-30% of the time, wave energy is available 90% of the time on average and the potential power contained in offshore waves is immense.”
Researchers say that their developed prototype can overcome key technical challenges that have been holding back the wave energy industry from large-scale deployment.
One of the most popular methods for wave energy harvesting is through a buoy-type converter known as a “point absorber”, which is ideal for offshore locations. They are cost-effective to manufacture and install. But they need precise synchronization with waves. Therefore, it calls for sophisticated systems involving sensor arrays, actuators and processors.
The prototype developed by the researchers of RMIT does not need any special circuitry. “By always staying in sync with the movement of the waves, we can maximize the energy that’s harvested,” Wang said.
“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.”
The prototype consists of two turbine wheels stacked on top of each other and rotate in opposite directions, and connected to a generator through shafts and a belt-pulley driven transmission system.
The prototype has been successfully tested at the lab scale, and the next step is 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.”