Australian Tidal Energy (AUSTEn) project has mapped a promising tidal energy site in the Clarence Strait, 50 kilometers north of Darwin.
To help understand the site’s suitability for tidal energy extraction, factors including tidal speeds, bathymetry, water temperature and seabed composition were characterised.
The Clarence Strait is one of two locations that AUSTEn prioritised for tidal energy generation; the first was Tasmania’s Banks Strait, which was the subject of a similar field campaign in 2018.
Project Lead A/P Irene Penesis said the Clarence Strait campaign had been a successful one and the early results were positive.
“Our initial measurements support our predictions that the Clarence Strait shows a lot of promise for tidal energy development.
“It’s early days but our initial measurements support our predictions that the Clarence Strait shows a lot of promise for tidal energy development.
“The tidal range is large, there are fast flowing tides and deep waters. The seabed was also flatter than expected, making it potentially suitable for deployment of tidal turbines.
“After we return in September to retrieve all our instruments and process and analyse the data, we will be able to provide tidal energy developers with the detailed information they need to make investment decisions in this location.”
Multiple criteria pointed to the Clarence Strait as a promising location for tidal projects, including predicted powerful tides, proximity to electricity grids and nearby energy demand.
In work led by Dr Mark Hemer from CSIRO, a model that simulates tidal currents and elevations around all of Australia identified the Strait as suitable for tidal energy extraction.
“The Clarence Strait was identified as an area with simulated high flow velocities – the total annual resource is estimated at approximately 1.75 TWh/yr – as well as suitable depths for technology deployment,” Hemer said.
“Harnessing even a small amount of this energy could contribute to the overall energy demands of the Northern Territory, which is about the same as the total Clarence Strait tidal resource.”
Harnessing even a small amount of this energy could contribute to the overall energy demands of the Northern Territory.
But it was only when combined with other factors influencing the financial viability of tidal projects that the project narrowed down its selection to the site, AUSTen says.
Dr Jenny Hayward from CSIRO leads work to assess the feasibility of connecting potential sites to existing power grids. This assessment identified an opportunity to connect energy generating devices in the Clarence Strait to the Darwin-Katherine interconnector or potentially to local microgrids.
“The Northern Territory Government has a stated goal of 50% renewable energy by 2030,” Hayward said.
“Including tidal would help to reduce emissions and reach this target, particularly as Darwin is predominately powered by gas-fired electricity generation.”
“As tides are known years in advance, the electricity generated from a tidal farm has the advantage of being completely predictable, Hayward added.
“This predictability would give grid operators the ability to schedule other forms of generation to fit in with the expected tidal generation.”
Energy from the Clarence Strait could also support economic development in off-grid locations such as the nearby Tiwi Islands, which are currently powered by solar and diesel generators.