Waves for future energy

ABB announced that its Performance Service Centre located in Port Kembla, NSW, recently completed the refurbishment of Oceanlinx’s 250 kW Wave Energy Conversion unit. The unit, which can save thousands of tonnes of CO₂ and SO₂ emissions annually, is a full-scale prototype with a commercially efficient system for extracting energy from ocean waves and converting it to electricity, or utilising that energy to produce clean, fresh water from brine.

ABB’s scope of work included fabrication modifications and installation of the Wave Energy Conversion unit hood and steel work — including stiffening sections of the structure and fabricating two watertight doors. All work was finished on schedule in early February, enabling the unit to be floated out to its operational location off the breakwater north of Port Kembla harbour, NSW. Oceanlinx has a power purchase agreement with Australian utility Integral Energy for the supply of electricity from the 250 kW prototype unit.

How does it work?

Oceanlinx’s core technology is an oscillating water column (OWC) device, based on the established science of wave energy, but one which, when compared to other OWC technologies, offers major improvements in the design of the system, the turbine and in construction technique. The technology has been successfully constructed and tested with the first full-scale Oceanlinx wave plant, installed at Port Kembla, producing zero CO₂ and SO₂ pollution.

Ocean waves contain enormous amounts of energy. As this energy passes the Oceanlinx device, the water inside the OWC chamber which is open underneath the waterline rises and falls compressing and displacing the air inside, driving it past a turbine which is housed at the narrowest point in the chamber.

Since the OWC chamber narrows, the air is accelerated to its highest velocity as it passes the turbine, allowing for maximal extraction of the energy. The oscillatory wave motion causes a similar oscillatory airflow through the chamber, and the turbine converts energy on both up and down stroke. The turbine converts the energy in the airflow into mechanical energy, which drives an electrical generator. The chamber and turbine are the essence of the Oceanlinx Wave Energy System.

Oceanlinx is developing new generations of its wave energy conversion technology with peak power outputs in excess of 1 MW, depending on the wave climate and specific power requirements. Multiple units can be deployed in the same general area, all connected back to shore by the one electrical cable, thus constituting a wave energy array to provide commercial-sized installations of up to 100 MW. The expected global market for wave energy could see a saving of more than one billion tonnes of CO₂ from the atmosphere each year on a like-for-like comparison with coal-generated power.