PERTH-based Carnegie Wave Energy Limited is taking another step toward making wave-generated electricity a viable reality.
In late December 2011 the company announced the detailed design for its Perth Wave Energy Project (Perth Project) at Garden Island.
The Perth Project is set to be a revenue producing, grid-connected, commercial demonstration plant. The venture will have two stages, one with a peak rated capacity of 2MW and the second of 3MW.
The initiative builds on the decade-long development and refinement of Carnegie’s CETO technology, which involves fully submerged seven-metre in diameter buoys tethered to seabed pump units. The buoys are optimally set 25 metres below the surface, but can go deeper.
“The buoys move with the motion of the passing waves driving the pumps which in turn pressurise water that is delivered ashore via a pipeline. On shore, high-pressure water is used to drive hydroelectric turbines, generating zero-emission electricity,” says Carnegie CEO Dr Michael Ottaviano.
“In essence, CETO is a pumping technology and the plant is a hydraulic plant replacing the hill with waves,” says Chief Operating Officer Greg Allen.
With the assistance of $12.5 million in WA Government Low Emissions Energy Development (LEED) funding, the technology has progressed through several stages, including CETO 3, a 1/3 scale pilot plant which underwent two years of ocean testing and high cycle onshore tests of key components.
According to assessments by UK engineering technology firm Frazer-Nash, CETO 3 has a peak rated hydraulic power capacity of 203kW in conditions such as those on the south-west coast of Australia.
The firm also confirmed that CETO 3 delivers enough sustained pressure to support sea water reverse osmosis desalination.
The submergence of the buoys gives CETO an advantage over other wave energy technologies currently being developed in that the potential for damage in extreme conditions is reduced.
Beyond this, according to a study by Curtin University’s Centre for Marine Science and Technology, the technology shows no significant environmental impact on underwater fauna.
CETO is already generating international interest. A next-generation commercial-scale unit has been manufactured and is undergoing final pre-deployment testing and fitting on France’s Reunion Island.
According to a 2011 CSIRO study, much of the world’s wave energy occurs on Australia’s Southern coastline, including a 25-metre deep isobath between Geraldton and Tasmania which contains 1300TWh/yr, about five times the total electricity requirements of Australia.
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Offshore WIND staff, January 20, 2012; Image: carnegiewave