Wave-powered water desalination, electricity generation now closer to reality
Sydney, Oct 18 : Australian researchers have conducted successful trials of a technology called CETO that makes commercial wave-powered water desalination and electricity generation closer to reality.
Dr Michael Ottaviano of Carnegie Corporation said the so far the trials have yielded promising results.
He said the tests, carried out in Fremantle, Western Australia, has verified predictions of how much electricity and water the technology could produce under various wave conditions.
“We've found a perfect correlation between the results our models predicted and what we've actually measured in the ocean, which is a major technical milestone,” said Ottaviano.
The CETO technology, first conceived by Perth-based inventor Alan Burns in 1975, consists of submerged buoys connected to seawater pumps fixed to the seabed.
As each buoy moves back and forward with the swell, it generates energy to pump seawater onto land at high enough pressures to drive a reverse osmosis desalination plant as well as hydroelectricity turbines.
The company said it has just spent two years developing a computer model of the buoy and pump system, which calculates how much power and water it can deliver back on shore according to different wave conditions.
The computational fluid dynamics model uses the same software used to design racing cars and boats for the America's Cup, he said.
“We can also now go to any number of sites, measure the wave conditions there, plug those conditions into our models and then tailor a design of the unit to each specific site that we go to,” said Ottaviano.
He said tailoring the units to particular sites would involve changing the buoyancy of the buoy and the design of the pump.
He said one of the challenges of wave farms was designing them to survive the massive force of storms.
While most wave farms float on the surface of the water and try to resist storms, the CETO is fully submerged, avoiding the highest force of storms, which is at the surface of the ocean.
It is also designed to be flexible and to go with the flow of the sea, he said.
“The way it moves in the water mimics a kelp forest,” he said.
As of now, Ottaviano is negotiating with state governments about possible sites in South Australia, Victoria and New South Wales for commercial scale demonstration wave farms.
These will be 50-megawatt power stations, producing 15-50 giga-litres of desalinated water per year. About 300 buoy and pump units will be used for each farm, Ottaviano added.
He said energy from the farms would cost around 80 Australian dollars per megawatt hour, around the cost of wind energy. The cost of water will be comparable to other desalination plants at around 1.50-2 Australian dollar per kilolitre, he added. (ANI)