Bringing wave power to tough ocean locations

A new design could allow wave energy to be efficiently harvested in the open ocean for almost endless renewable power

Spotted: The ocean is a tremendous, untapped resource for green energy. According to wave power company Mocean, harnessing just one per cent of global wave energy could power more than 50 million homes and save more than 50 million tonnes of CO2 annually. However, while a number of tidal projects are being developed, there are no commercially successful wave power devices in operation today. This could be about to change, as Mocean is set to deploy its first wave power pilot project.

Wave power differs from tidal energy. While tides are generated by the effect of gravity on the oceans, waves are caused by wind blowing across the ocean’s surface. Tidal turbines work best in narrow passages of water, which naturally channel tidal energy through the turbines, whereas wave energy converters can be placed in the open ocean. Proposed designs use floats that rise and fall with the waves to compress a hydraulic piston, turning a generator.

Now, Mocean is developing two new wave energy technologies. The ‘Blue Star’ is designed to fit in a 40-foot shipping container and uses magnetic-geared power to charge on-board batteries, providing continual power. Meanwhile, the ‘Blue Horizon’ is a larger device designed for use in wave farms that would generate electricity at grid scale. Both technologies are based on the same concept – a hinged raft with “a unique geometry that improves performance by up to 300 per cent compared to traditional hinged rafts.”

Company co-founder and managing director Cameron McNatt describes the technology as “a simple mechanical system, which when integrated with direct-drive generators ensures reliability. The hinge allows for large rotations, eliminating the possibility of end-stop impacts, and the sloped ‘wave channel’ on the bow cause the machine to dive through large waves; both of which ensure survivability.”

Wave energy conversion is a relatively new idea, but there are already several projects that aim to harness the ocean as a power source. Some of these innovative ideas include one that uses wave line magnet technology and an underwater generator that uses deep-sea ocean currents to generate power.

Written By: Lisa Magloff