Energetech’s wave energy technology

The power of ocean waves has long been recognised as one of the great untapped energy resources with more than 1,000 patents filed for technologies to harness that energy in the last two hundred years and none that have yet reached commercial realisation. When that goal is reached, it will be a day worth celebrating as the World Energy Council believes that enough energy could be extracted from waves to meet the world's entire electrical energy needs. One company on the verge of commercialisation of wavepower-derived energy is Australian company Energetech. Energetech Australia is working on a new and commercially efficient system for extracting energy from ocean waves and converting it to electricity as a cheap, sustainable source of power. The company has a pilot installation in Port Kembla, NSW and has just received an investment of AUD$500,000 from the Centre for Energy and Greenhouse Technologies (CEGT) for the deployment of the first commercial wave energy converter off the Victorian coast.

In June 2004, a report by the U.S. Electric Power Research Institute (EPRI) identified Energetech’s wave technology device as the one of a few ocean energy technologies around the world that had overcome most of its technical challenges.

According to Mr Jan Dekker, Managing Director of CEGT, Energetech will use the $500,000 for the development and deployment of its first commercial unit based on testing and performance results from the first prototype. The prototype at Port Kembla weighs 485 tonnes and stands 40 metres high by 35 metres long by 18 metres wide.

"In particular, the funds will be applied to the development of a more compact commercial Energetech wave energy converter to be located in Victoria that is targeted to generate up to four times the electrical output of the existing prototype plant," Mr Dekker said.

"We will also provide support for the deployment of a Victorian pilot plant, and several potential sites along the Victorian coastline will be investigated. The Victorian installation will support the local economy through the supply of manufacturing, construction and maintenance services."

Mr Dekker said ocean power had many advantages over other renewable energy forms, including that waves are more consistent than wind and sunshine and hence can improve on the intermittency of renewable energy sources such as wind and solar; and because water has 835 times the density of air, more energy is available from moving water (tides, currents, waves) than from moving air (wind).

The Energetech wave energy converter is described as an oscillating water column wave energy type device, as it harnesses energy from the vertical movement of ocean waves. The key innovation in the converter is a variable pitch blade turbine that operates in combination with a concentrator that increases the amount of energy that can be extracted from the water movement. Animations of the system that clearly demonstrate how the technology works can be viewed as either flash or AVI here.

The variable pitch turbine blades allow the turbine to extract power from both the wave peak and the wave trough under the concentrator. During the wave peak, air is pushed up and compressed in the concentrator chamber to drive the turbine, which is connected to a generator.

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