Fresh Water From Down Under the Waves

Growing populations, increasing agricultural activities and new industries all need one thing: freshwater. And increasingly, they need more of it than is locally available. This is especially true for largely arid Australia.

The Australian water desalinization plant, powered by wave energy, being towed into Port Kembla harbor. © ENERGETECH AUSTRALIA

Because it is surrounded by oceans, many Australians have wondered for years if desalinization could provide fresh water to the country’s growing population. But desalinization is an energy-intensive process (most existing plants use coal or gas), and has thus far proved prohibitively expensive for most communities. And the question of what to do with the salty brine that’s left from processing has led some Australian environmentalists to oppose the idea.

Now, two Australian companies, Energetech and H2AU, have joined forces to test a desalinization plant that is run on wave energy in Port Kembla harbor. By using the free power generated by the ocean’s waves to drive reverse-osmosis desalinization, not only is air pollution eliminated but energy is conserved (since it is used right where it is produced, instead of losing strength through transport). “Costs will therefore be well below any other form of desalinated water,” explains Tom Ebersold, chief executive of Energetech.

Ebersold adds, “With our system, we are able to mix the resulting brine back into the ocean with no impact.” That’s because the plant will be located offshore, where the brine can be mixed into open water without affecting near-shore ecosystems.

The plant will produce 500 megawatt-hours of electricity per year, some of which will be fed back into the electricity grid. The rest will be used to make more than 500 gallons of fresh water per day. According to Ebersold, “The water produced at the first test passed the Sydney water board standards, and commercial units are being worked on for various locations.”

A similar wave energy pilot project is also scheduled for a location two miles off the coast of Rhode Island in Block Island Sound. Called Greenwave Rhode Island, it will use Energetech technology, minus the desalinization element. Charlie Moret, managing director of marketing and communication for Connecticut Innovations, which administers the Connecticut Clean Energy Fund and provided seed money for the project, says the states of Connecticut, Rhode Island and Massachusetts have all helped fund the $3.5 million endeavor.

“The project is currently working through an extensive siting and permitting process,” says Moret. “It will have a relatively low profile, and may actually benefit marine life by serving as a place for them to feed. Pressure differences caused by wave action will drive the turbines, regardless of flow direction.”

According to Moret, “There is a lot of interest in the region in innovating renewable energy programs, away from fossil fuels.” The same seems to be true Down Under.