Wave energy’s huge potential could be unlocked by the power of sound, says research

Ocean waves have long been seen as having huge potential as a source of renewable energy. Waves produce an estimated 50 trillion to 80 trillion watts of power worldwide – nearly two to three times the world’s current annual energy consumption.

Many devices have been designed to capture and convert waves’ great power into electricity, but today’s technologies face challenges in efficiency, particularly in deeper waters. As a result, wave energy hasn’t yet taken off as a renewable source in the same way as wind and solar.

One way around this problem lies in the interaction between two types of waves: those on the ocean’s surface, and those that reside underwater. My research group has just published a paper demonstrating how underwater sound waves can be used to make surface waves more powerful, potentially making them a more viable source of energy.

The same insights could also eventually be used to reduce the risks of tsunamis by making them smaller. In addition, in a second new paper we show how underwater waves can be used to improve today’s tsunami early-warning system.

The waves on the surface of the ocean are often created by a combination of wind raising up water and gravity pulling it back down – hence they’re sometimes referred to as surface-gravity waves. On the other hand, their underwater counterparts are sound waves produced by phenomena like earthquakes or volcanic eruptions, sometimes thousands of metres below the surface.