A section of Bass Strait off Victoria’s Gippsland coast has been declared an offshore renewable energy zone and may become home to Australia’s most advanced offshore wind project.
Victoria’s wild coastal winds look set to power a new renewable energy industry for Australia with the Star of the South offshore wind farm achieving major project status. Environmental assessments along the Gippsland coast are currently underway to inform project planning and approvals. If it proceeds, Star of the South may supply up to 20 per cent of Victoria’s electricity needs.
Australia’s most advanced offshore wind project, Star of the South, was awarded a Commonwealth Exploration Licence in 2019 and its recent major project status will help it to navigate government approval processes.
Myles Daniel, Star of the South’s Engineering, Procurement and Construction Director, describes the project as a beacon for an entire offshore wind industry for Australia.
“We need more diverse ways of generating renewable energy, and offshore wind is something that can be deployed at scale,” he says. “It can be a really important part of Australia’s future energy mix, but you need a project to get going, and that is where I see Star of the South setting the foundations for an entire industry.”
Winds of change
Backed by Danish fund Copenhagen Infrastructure Partners and the Australian superannuation fund Cbus, the 2.2 gigawatts Star of the South project is expected to provide power for up to 1.2 million Victorian homes.
The project supports a broader offshore wind ambition for Victoria, with the state government’s recent Offshore Wind Policy Directions Paper outlining a staged approach to targets that will help it to halve its emissions by 2030 and reach net-zero by 2050.
Victoria’s blueprint for offshore wind also creates more certainty around the phase out of coal-fired power stations. Last year, Energy Australia signalled it would close the Yallourn power station in Gippsland’s Latrobe Valley in 2028 – four years earlier than planned. It typically takes about 10 years to develop and build an offshore wind project.
The proposed location for Star of the South stretches along the south coast of Gippsland, close to towns such as Port Albert and Woodside Beach. Up to 200 turbines are proposed to be installed at a distance of between 10 km and 25km from the shoreline. While a turbine model is not yet selected, the project is exploring models with a blade tip height of up to 350 metres.
Star of the South is investigating a turbine sea depth of between 20 and 55 metres. It is also exploring the use of steel monopile foundations, which Daniel says are the most commonly used support system for offshore wind turbines at this depth.
“We are looking at a diameter of up to 12.5 metres for the monopile foundation and the length could be up to 74 metres long, with about 50 metres into the seabed,” he says.
To help reduce construction impact on marine life, Daniel says the project is exploring a noise mitigation technology known as a double bubble curtain.
“It essentially has two rings on the seabed that blow bubbles upward into the water column to reduce the noise,” he says.
Connecting to the grid
Star of the South is expected to have up to four offshore substations within the licence area.
“This is where we gather all of the electricity from the offshore wind turbines through sub-sea cables, which are buried below the seabed,” says Daniel. “Once we’ve collected it, we step the voltage up from 66 kilovolts to anywhere between 220 and 275 kilovolts and then bring it to shore via an export cable.”
The transmission line will connect to Latrobe Valley, using existing infrastructure that will become idle when Yallourn power station closes.
“The strongest node in Victoria is the Latrobe Valley,” says Daniel. “When the power plant at Yallourn comes offline, this will create capacity at those nodes and will also create an opportunity for workers at Yallourn to transition to offshore wind.”
Succeeding by design
Nick Fleming, National President and Chair of the Board of Engineers Australia, says the emerging offshore wind industry presents opportunities for engineers, but the infrastructure must “succeed by design”.
“If offshore wind farms are to gain the level of adoption that we need to facilitate the clean energy transition at pace and scale, we need them to be a good experience so that sustained support by citizens and politicians comes easily,” he says.
“This is a macro-design issue for engineers – not a micro-design issue,” adds Fleming. This includes consideration of logistics and supply chains over the economic lives of wind farms, as well as reuse or recycling at the end of life.
He notes that engineers should also consider the wider social context of wind farm infrastructure.
“For example, extending the notion of engineering design into enabling local industry to be active, successful players may require some adjustments to the technical design of the wind farm. But this would play a critical role in maintaining support and achieving commercial success.”
Demand for skills and supplies
The offshore wind sector is booming across the globe. Europe, for instance, is the industry leader and home to more than 120 offshore wind farms. Daniel says the industry has the potential to generate huge quantities of power in Australia, but skills and supplies present a challenge.
“We need a lot of specialist resources, factories and vessels from all around the world to help get the industry going, so that we can get the critical mass to build our own offshore wind industry in Australia,” he says. “We can’t build a supply chain off one project.”
Boosting the supply of engineers also presents a challenge.
“Like all sectors, [the] energy [sector] needs to be smarter in securing and using engineering capability – both people and technologies,” says Fleming.
“Fields of practice involving sustainable technologies are also very attractive to our next generation of engineers,” adds Fleming. “Internships should be examined to provide the opportunity to bring in younger engineers sooner to develop their industry experience and engagement for the longer haul.”
Climate Smart Engineering 2023 (CSE23) will be held 29-30 November 2023 at the Melbourne Convention and Exhibition Centre. Call for abstracts and registrations are now open.
Abstract submissions close 11.59 pm AEST on Wednesday 12 April 2023.