Human settlements

Renewable energy

Wave 02: Installation and demonstration of a 20kw offshore wave-energy system

Renewable Energy Commercialisation in Australia, Australian Greenhouse Office, 2003
NOTE: The status of these projects will have changed since the time of publication, and project contacts may also have changed.

OPT has developed a sophisticated system to harness the energy of ocean waves for the generation of low-cost, pollution-free electricity.

Ocean waves represent the most concentrated form of renewable energy and abundant resources are available around Australia's lengthy coastline. However, finding a reliable and efficient method to extract that power has long been a barrier to commercial wave-energy production. Over the past couple of years, this has begun to change with the emergence of various new wave-energy technologies. An Australian subsidiary of a United States company is currently embarking on a trial to demonstrate the economic viability of its innovative offshore wave-energy technology.

Ocean Power Technologies (Australasia) Pty Ltd (OPTA), a subsidiary of Ocean Power Technologies, Inc. (OPT), has the fullylicensed rights to the OPT wave-energy technology and expects to develop its own related proprietary technology for licensing back to OPT. Supported by a $230,000 grant from the Renewable Energy Industry Program, OPTA is developing and installing an initial 20kW wave-energy generation system, to be moored to the seabed several kilometres off the Victorian coast near Portland. The wave energy converter, called the PowerBuoyTM, is fully-submerged and resembles a large ocean buoy. It will generate renewable electricity for transmission via submerged cable to the grid, where it can be sold to retail customers.

The competitive advantages of OPT's technology over other wave-energy systems include its proprietary computerised control system which is housed in a watertight canister attached to the buoy, plus the in-ocean experience of the PowerBuoyTM, the simplicity of its offshore system design, and its marine survivability. The up-and-down motion of ocean waves is harvested by the piston-like PowerBuoyTM, driving a hydraulic cylinder and the power generation equipment. This power can then be transmitted to shore via the underwater cable. OPTA has held extensive consultations with the Marine Board of Victoria, the Department of Natural Resources and Environment, Environment Australia, Mirimbiak Nations Aboriginal Corporation and fishing groups, and the systems will be fixed to the ocean floor to minimise the risk of interfering with migrating whales.

The PowerBuoyTM system is designed to be economically competitive with fossil fuels and it is likely that initial equipment sales will come from isolated diesel markets. In the longer term, though, OPTA is confident that its technology will be competitive against large coal-fired power generation. Competitive local steel fabrication facilities and other local vendors for deployment and maintenance are utilised to minimise the cost of the system.

Electricity from an installation of multiple PowerBuoyTM units is expected to cost around 7 to 12 cents per kilowatt hour (kWh) to run compared to the 25 to 50 cents per kWh for diesel-fired generation. This also compares favourably with other renewable sources of energy. Another benefit of OPT's technology is its durability. As it is based around a number of existing proven technologies such as ocean buoys, marine-quality hydraulics and conventional moorings, the unit is estimated to have a useful life of at least 30 years.

The OPTA system incorporates special mooring, flotation, anchoring, data-logging and navigation-aid systems for use in the future scale-up of the system. Because the system is modular, the total generating capacity can be easily increased by installing more buoys, using the same production and deployment facilities for use in either grid-connected or isolated power networks. This system will be used primarily to demonstrate the technology to prospective buyers throughout the Australasian region, while the US Navy has already contracted for a larger system to be installed off one of the Hawaiian Islands.

For more information please contact:

Thomas Scott-Morey
Ocean Power Technologies (Australasia) Pty Ltd
Level 25, Exchange Plaza
2 The Esplanade
Perth WA 6000
Tel 0421 99 55 90
Fax (08) 9267 0878
Email ts-m@bigpond.net.au

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