Aussie firm sees buoyant future in wave power

For millennia, Australia's rugged southern coast has been carved by the relentless action of waves crashing ashore.

The same wave energy could soon be harnessed to power towns and cities and trim Australia's carbon emissions.

"Waves are already concentrated solar energy," says Michael Ottaviano, who leads a Western Australian firm developing a method to turn wave power into electricity.

"The earth has been heated by the Sun, creating wind, which created the swells," he told Reuters from Perth, saying wave power had the potential to supply all of Australia's needs many times over.

Mr Ottaviano heads Carnegie Corp, which has developed a method of using energy captured from passing waves to generate high-pressure sea water. This is piped onshore to drive a turbine and to create desalinated water.

A series of large buoys are tethered to piston pumps anchored in waters 15 to 50 metres deep. The rise and fall of passing waves drives the pumps, generating water pressures of up to 1,000 pounds per square inch (psi).

This drives the turbine onshore and forces the water through a membrane that strips out the salt, creating fresh water in a process that normally requires a lot of electricity.

The CETO (named after a mythical Greek sea creature) pumps and buoys are located under water, differing from some other wave power methods, for example, those that sit on the surface.

The CETO concept was invented in the 1970s by a Western Australian businessman Alan Burns and initial development began in 1999, followed by completion of a working prototype by 2005.

Mr Ottaviano says the company, which works in partnership with British-based wind farm developer Renewable Energy Holdings and French utility EDF, is in the process of selecting a site for its first commercial demonstration plant in Australia.

The 50-megawatt plant, enough to power a large town, would cost between €153 million to €204 million and cover about five hectares of seabed.

Funding could be raised from existing or new shareholders, he believed.

Several sites in Western Australia, including Albany in the south and Garden Island off Perth, looked promising.

"There's significant interest in these sorts of projects, even in the current financial environment," he added.

And a 50-MW plant was just a drop in the ocean.

He pointed to a study commissioned by the company that said wave power had the potential to generate up to 500,000 MW of electricity along the southern half of Australia's coast at depths greater than 50 metres.

At shallower depths, the potential was 170,000 MW, or about four times Australia's installed power generation capacity.

Interest in renewable energy in Australia and elsewhere is being driven by government policies that enshrine clean energy production targets as well as state-backed funding programmes for emerging clean-tech companies.

"Australia is going to be one of those markets because of what the government is doing to drive investment in this sector. For starters, there's quite a bit of direct government funding for projects like this," he said.

The company's bioWAVE system is anchored to the sea bed and generates electricity through the movement of buoyant blades as waves pass, in a swaying motion similar to the way sea plants, such as kelp, move.

Tidal power, in which electricity is generated by turbines spinning to the ebb and flow of tides, has not taken off in Australia, partly because of cost, but is expected to be a big provider of green power in Britain in coming years.

Last week, Britain announced five possible projects to generate power from a large tidal area in south-west England. The largest of the projects could generate 8,600 MW and cost €22.6.

Mr Ottaviano believes wave power is one of the few green technologies that can provide steady, or base-load power.

Wind and solar photovoltaic panels can only operate at 25 to 30 per cent efficiencies because neither the wind nor the sun are permanently available.

Government policies should promote the development of technologies that delivered large-scale, high-availability clean power competitively, he said.

Australia has large geothermal potential in remote central and northern areas.

"Wave is another logical one because it is high availability. It is 90 to 100 per cent available in most sites around southern Australia."

"You could power the country 10 times over."

Factbox

Main types of renewable energy technology under development by companies in Australia.

Wind
Australia already generates nearly 1,000 megawatts (MW) from wind and an estimated 4,000 to 5,000 MW of additional wind power capacity is expected to be added over the coming decade, providing there is enough investment in transmission lines.

The vast majority of windfarm sites are in the south along the coasts of southwestern Western Australia, South Australia, Victoria and Tasmania states.

Solar panels
An increasing number of Australian homes are installing small capacity solar panel systems on their roofs. Government subsidies and payments for feeding excess power into the grid will continue to drive investment but the solar industry is calling for the subsidies to be expanded to 5,000 watt systems, instead of 1,500 watts, because that is much closer to the real electricity consumption of most Australian homes.

Australian firm Solar Systems is developing a 154 MW photovoltaic power station in north-east Victoria.

Solar storage
Some firms are developing 24-hour solar power. Lloyd Energy Systems in Sydney is developing solar towers that capture and retain the sun's heat in graphite blocks on top. The sun's energy is directed at the blocks by arrays of mirrors. Water is run through the blocks, generating steam that drives a turbine.

The heat is retained by the blocks at night, allowing the turbines to keep spinning.

Geothermal
Numerous companies are looking to tap large areas of heated rocks about three to five kilometres below the surface to generate power. Near the centre of the country in particular, there are large areas of high-heat producing granites that contain radioactive elements that produce heat as they decay.

South Australia has been a focus of firms looking to explore and invest in geothermal power, using the heat extracted from rocks between 200 and 300 degrees Celsius to generate power. One of the main companies, Geodynamics Ltd, plans to have a 50 MW power plant operating by 2012, and eventually aims to produce 10,000 MW, or about 10-15 coal-fired power plants.

Wave
Carnegie Corp. of Western Australia is refining a method of using energy captured from passing waves to generate high-pressure sea water. This is piped onshore to drive a turbine and to create desalinated water.

Reuters