We Can Now Turn Ocean Waves into Electricity and Fresh WaterMay 24, 2016
An Australian company is on the brink of revolutionizing the green power movement with the latest version of its wave energy technology that harnesses electricity from the movement of the ocean.
This innovative system developed by Carnegie Wave Energy is named CETO, after a Greek sea goddess. The latest version – CETO 6 – incorporates submerged buoys anchored to the sea floor that move up and down with the ocean swell. This movement powers an on-bard hydraulic pump, turning kinetic energy into electrical energy, which is then transferred to a facility onshore via undersea cables.
In addition to electricity, the CETO system also supplies freshwater, as the energy generated can be used to both pump sea water on shore and operate a reverse osmosis desalination plant.
Design for the latest iteration of the CETO wave energy technology
The potential value of harnessing the waves, according to Carnegie Wave Energy’s CEO Dr. Michael Ottaviano, is that “wave energy has been estimated to be able to supply more than the whole world’s current power consumption.” While the idea of harvesting ocean energy isn’t new – the first patent for a device dates to 1799 – only recently have researchers made significant headway on creating resilient and efficient hardware.
An earlier iteration of this technology – CETO 5 – was first successfully implemented on an island off the coast of Perth in 2014. Three buoys, each producing 250 kW, successfully operated for 13,000 cumulative hours at a depth of 5.8 m in waves over 3 m. CETO 6 sees the buoys upgraded to providing 1 MW each, as well as being capable of operating at greater depths and higher sea states.
Animation of how CETO 5 works
Carnegie Wave Energy is now experimenting with the idea of “micro grids“, which combine CETO’s ocean-sourced electricity and freshwater with solar panels and battery storage, to enable coastal and island communities to autonomously generate all the energy and water they need on-site. The first micro grid will be at that same island off the coast of Perth.
In addition to CETO’s particularly high energy output and added capability of producing freshwater, the fact that the buoys are submerged makes CETO distinct from other wave energy initiatives. Not only does it make for a much more aesthetically pleasing option, it also means the buoys are less affected by storms.
Wave energy offers certain advantages over solar – namely that a wave farm is smaller than a solar farm for a comparable output, and waves are much more consistent and predictable around the world, whereas solar’s effectiveness is reduced by cloud cover and short winter days.
Another endearing benefit of the technology is that CETO buoys act as artificial reefs and promote marine biodiversity. As Dr. Ottaviano explains of the experimental CETO 5 rig near Perth, “we increased the amount of marine life from about seven species before the system was deployed to 27 species when it was operating.”
Marine life swimming around a CETO buoy
Carnegie Wave Energy may soon be coming to a shore near you. It has a plan for a 10 – 15 MW project in the UK, as well as major projects in the pipeline for Ireland, Canada, Bermuda, Chile, and micro grids in Mauritius and other remote areas and islands.