In the search for a more sustainable energy mix, solar, wind and nuclear power are clearly dominating the discussion. But there’s another source of renewable energy that has great potential: ocean waves.
“Unfortunately, no wave energy technology has managed to be cost effective until now”, says Oceanographer Tom Denniss. “But we believe that will soon change”.
Tom and his team at Australian energy technology company Wave Swell Energy (WSE) are about to prove that wave energy has the potential to become a serious player in sustainable power generation. WSE is about to construct and launch a 200 kW wave energy project on King Island, with Hydro Tasmania integrating the electricity from the unit into the local hybrid grid, alongside its existing wind, solar, and diesel generation.
Producing energy through waves at a competitive price
Proving that wave energy can be captured in a cost-competitive way has long been a challenge for the sector. WSE is aiming to demonstrate this capability via the King Island project – and as a result of that to become the first wave energy technology to enter the commercial phase.
According to Tom, the issue with many of the previous technologies has been that they were developed by mechanical engineers. Most of them were experts with machinery with moving parts. But, moving parts in the ocean have proven to be a fatal flaw with most of the technologies that trod that path.
“If you have moving parts in the water, the technology is going to be too cost-intensive to maintain.” says the WSE founder.
The WSE technology has no moving parts whatsoever in the water, meaning that issues such as damage from the waves, corrosion, and access for maintenance can be avoided. In addition, there is no adverse impact on marine life.
Artificial blowholes generate energy and provide coastal protection
To overcome these challenges, WSE leverages the concept of the oscillating water column. In simple terms this means that they have developed artificial blowholes to generate energy through the natural movement of ocean waves.
Like in an underwater cave, the water rises in an artificial chamber with the incoming wave. As waves fall, they suck air back through past an air turbine, which is the only moving part in the construction.
To further reduce the complexity, WSE has developed a one-directional air turbine which is expected to further extend the life of the technology, as well as improve the efficiency of converting the energy from the waves into electricity.
One technology – multiple applications
WSE sees the most obvious application for their technology in displacing diesel generation on islands. Even large diesel generation markets such as Hawaii would benefit from the cost reduction through WSE technology compared to diesel. Smaller and more remote islands are expected to benefit to an even greater extent.
On top of their cost saving potential, waves have the advantage of being more predictable and consistent than either wind or solar energy. This means that waves could complement the use of traditional fossil fuel generation in a way that other renewable energy sources sometimes find difficult because of their shorter timeframes of variation.
What’s more, WSE’s technology has applications beyond energy generation. It can be used to produce hydrogen and desalinate water.
“But, one of the biggest benefits is that the units can also function as breakwaters to prevent coastline erosion”, explains the inventor of the technology. “Breakwaters are usually a sunk cost, but there’s a real opportunity for communities to turn them into a source of revenue.”
In fact, this potential has recently been recognised by the Australian Research Council who provided a grant to a consortium comprised of WSE, Swinburne University, UNSW, Adelaide University, and Moyne Shire. The aim of the $2.3 million is to optimise the use of WSE devices to maximise power production while, at the same time, minimising the effects of coastal erosion.
With patience to a commercially sound wave energy concept
While Tom has always believed that it was possible to capture energy through waves, it has been a long path to get to King Island. With A PhD in Mathematics and Oceanography always new that he wanted to do something practical with his knowledge and has been working in the wave energy sector since 1999.
“I never found the technical challenges insurmountable’, says Tom. “Securing funding on the other hand is a bit of a grind.” But as someone who has once held the world-record for circumnavigating the world on foot, one could argue that endurance and persistence are amongst Tom’s greatest strengths.
After having held several senior roles in the sector, Tom founded WSE in 2016 and assembled a team of ocean energy experts with over 70 years of experience between them.
At the time of writing, Wave Swell has raised over $8 million dollars, much of it as equity funding, in order to finance the King Island project and the company’s general activities.
Bringing wave energy into international markets
In addition to working on the launch of the King Island project – with the technology expected to be operational late in the Australian summer – WSE is busy filling their project pipeline.
“We are having a lot of very positive conversations with islands in the Indian and Pacific Oceans”, says Tom about the future about the business. ‘But the great thing about wave energy is that it’s a truly global concept that can be applied anywhere with decent waves.”