New CSIRO research has found the consistency and predictability of ocean waves means the energy it generates could play an essential role in improving the reliability and stability of a renewables-powered grid, writes Gavin Dennett.
The research by Australia’s national science agency was commissioned by Wave Swell Energy to determine if wave energy converters add the most value to a future energy system when deployed alongside wind and solar resources, which are more variable and intermittent than wave power.
The CSIRO concluded the deployment of wave energy machines off the coast of Southern Australia would deliver more stability and reliability to a future clean electricity grid, and reduce the cost of buying batteries to store renewable energy.
The study found the consistency of wave power can deliver commercial advantages in hybrid applications by reducing the need for energy storage and smoothing inconsistent availability of wind and solar power due to weather variations.
Modelling of multiday interruptions to supply found that deploying a combination of solar, offshore wind and wave power, coupled with battery storage, would require less than half the capital expenditure of a system with just solar, offshore wind and battery storage.
“We have increasingly sophisticated tools that can accurately predict waves and their size in a given location,” says the company’s CEO, Paul Geason.
“CSIRO’s research shows Australia’s oceans can complement wind and solar to provide a dependable supply of energy in a variety of weather conditions, helping to bring down the price of electricity in a network that is increasingly dependent on intermittent renewable sources.”
Wave Swell Energy has just completed a successful 12-month trial of its groundbreaking UniWave200 device off the coast of King Island, 80km from the northwest tip of Tasmania.
The trial has seen the 200kW device supplying King Island’s microgrid with power since June 2021 in tandem with other renewable energy sources.
The $12 million UniWave200 – the Australian Renewable Energy Agency tipped in $4 million in funding – captures air pressure in a tube that is formed from the rise and fall of water, which then powers a turbine to create consistent and reliable electricity.
Geason says Australia has the potential to become a world leader in wave energy, and the CSIRO research identifies two sites off the coast of Victoria – Cape Nelson and Warrnambool – and Carpenter Rocks in South Australia as ideal locations for wave energy production due to their wave characteristics, proximity to transmission infrastructure and exclusion from marine parks.
These findings add to existing research that has identified Australia’s southern coastlines as significant potential as renewable energy sources.
However, Wave Swell Energy is currently focusing on securing contracts from the US and Europe due to more supportive markets and government policies than currently found in Australia.
“Our pilot demonstration on King Island has proven wave power can supply energy in a variety of weather conditions, boosting reliability and stability while also reducing the cost of guaranteeing energy supplies,” says Geason.
“We know wind and solar can produce vast amounts of low-cost energy, but developing complementary technologies – including wave power and storage – will be key to unlocking the greatest benefits.
“The sun doesn’t always shine and the wind doesn’t always blow, but waves are predictable and will help to fill those gaps.”