Waves of Energy and Water

As a surfer, and with limited time on my hands im always checking the web swell forecast to see whether its worth heading down to Bells Beach (yes it’s always busy). Luckily using swell maps and now dedicated surfer websites you can actively predict days its worth grabbing the board and heading out for a few waves. When your out on your board looking across the sea, its not hard to wonder just how much energy is wrapped up in each line of swell that stretches out to the edge of your vision. Im obviously not the only one to have thought this, because as we know there have been numerous attempts to capture this energy with wave conversion devices. Energetech, is the latest Australian company that is having significant success in this field.

Excluding tidal, ocean current and thermal ocean devices, the types of technology we have had (off the top of my head)

  • Hinged systems that float on the surface driving hydraulic or linear generation devices as they flex (eg. Ocean Powers – Pelamic )
  • Tethered systems that capture the forces generated by buoyancy and wave oscillation, and
  • Blow hole devices that utilise wave oscillations and an air column to drive a wind turbine, or
  • basic variations of the above

The latter type blow hole device has been attempted a number of times with limited efficiencies. This has been primarily to do with the challenge of extracting energy from a wind stream that varies in direction and power. Energetechs’ system utilises a turbine blade with variable pitch control that ensures it only ever rotates in one direction and adjusts its vane pitch as the wind speed changes to achieve greatest power generation. Standard propellers/turbines would have to reverse direction and have a small power band in a similar situation.The company then couples this turbine technology with a generator and mounts it onto large wave focusing collector which directs the incident wave power into a vertical blowhole chamber. The clever thing that Energetech has done beyond this is that they have connected a pump and desalination system.

The system now allows them to site energy generation or water purification systems off the coasts of Australia and other countries to provide pure drinking water at very low cost because the intensive energy/emission demands of desalination are taken care of. Secondly, offshore siting results in less waste brine disposal issues and shoreline land allocation issues. Plus that long term predicability I was talking about earlier means that power network integration is less of an issue and the device can be turned on and off instantly to cope with demand.

Energetech have an operational full scale ocean trial system operating of Pt Kembla in Australia, which will produce well over 500MW annually.

“Energetech has released plans to site wave generation plants in Portland. Energetech, a privately owned company, is going through planning approvals for a 1.5 to 2-megawatt wave generation plant and negotiating with a major power group to build a 20-megawatt plant.

A Victorian state government spokesman said Energetech had held discussions with Sustainability Victoria about the plans but it had not yet reached the public discussion phase. Talks have reportedly also been held with the Portland aluminium smelter about the supply of power.

Future facilities will cost about A$2 million per megawatt of capacity to build, according to the company. This compares with A$1.8 million for wind power and A$1 million for gas-fired generation.” source:Freehills

Energetech plans a listing on the ASX (Australian Stock Exchange) in 2007. CEO, Tom Engelsman from Energetech will be presenting at the AustralAsian Cleantech Finance & Investment Forum, Aug 22nd 2006.

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Nick Bruse is the General Manager of
Clean Technology AustralAsia Pty Ltd, the organiser of the AustralAsian Cleantech Forums and Dealer Forums, and the leading advocate of Cleantech in Australia. Nick does a weekly blog column on Cleantechblog profiling innovative Australian cleantech, energy, water and environmental technology companies.

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