First wave energy plant soon to sell electricity

www.sciencewa.net.au
26 Sep 2012

AUSTRALIA'S largest naval base is about to host and exclusively benefit from the first demonstration wave energy plant in the world, putting Perth at the forefront of wave energy development. Soon to be developed on the Department of Defence's HMAS Stirling base on Garden Island, the Perth Wave Energy project will be the first grid-connected wave energy plant to produce retailable electricity.

As such, it will also be the first demonstration project to validate the technology as commercially viable. Expected to power up to 25% of the base's annual energy needs, the two MW plant culminates 10 years of research led by Carnegie Corporation Wave Energy, which so far has invested more than $50 million to get the technology to where it is. According to Carnegie Corporation chief operating officer Greg Allen, that investment was worthwhile in that it helped develop the CETO 5 unit. "The technology itself consists of a buoy, a rope and a pump which is a hydraulic cylinder the same as you'd find on an excavator", Allen said.

CETO distinguishes itself from other wave energy devices by operating fully submerged and anchored to the ocean floor. "We're using the wave force to push down against the buoyancy, and as the buoy moves down, the seabed-mounted wave activated pump drops and draws fluid [water and a few additives] in, until the motion of water molecules in the wave reverses and wants to go back up. "The buoy then moves up and pulls on the pump, so it's just dropping, drawing fluid in, pulling up and pushing fluid out in a closed loop. "Essentially the energy that we get is in the form of pressurised fluid that we pump ashore via a subsea pipeline to generate electricity onshore".

The Perth Wave Energy project will consist of five 10m diameter buoys that will be linked to shore by a set of two 3.2kms heavy steel pipelines. A generator will sit onshore and put the produced energy into the grid. Partly government-funded, the $32 million project is officially branded as a demonstration project, even though it will be the first revenue Carnegie Corporation makes from CETO. "This project will be our first revenue from selling electricity from our technology", Allen says. Allen says the Perth Wave Energy project has a 25 year design life and is likely to be expanded. Carnegie Corporation Wave Energy is currently contemplating several commercial opportunities for CETO in New South Wales, Victoria and South Australia, as well as internationally.