AusNet Services is currently building the transmission connection assets for Stockyard Hill Wind Farm, which when complete, will be the largest wind farm in the Southern Hemisphere.
If you live in regional Victoria, you may have been lucky enough to witness the recent spectacle of the mammoth 600MVA, 3Phase, 500kV/132kV/22kV transformer weighing in at 600 tonnes (when in operation) on the road, heading from the Port of Geelong to Lismore, Victoria.
The transformer is arguably the most impressive piece of AusNet Services’ transmission assets it is building for the wind farm, which includes a 70km 132kV transmission line that will connect the wind farm to the new Haunted Gully Terminal Station.
The journey of the 663 tonne superload rig took three nights and comprised of two 14-axle platform trailers, hauled by five prime movers at an average speed of 20km/hr. VicRoads escorted the delivery the entire way as it travelled between the hours of 11pm and 5am. It is the biggest superload that south-western Victoria has seen in recent times.
Transporting such a huge rig took months of planning. Both Toshiba, the manufacturer of the bespoke transformer, and AusNet Services worked closely with VicRoads to ensure the smoothest and safest possible route. Given the load covered two lanes, traffic lights had to be removed and replaced, powerlines lifted, and steel supporting structures were carefully placed over important infrastructure such as bridge crossings and culverts.
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Head of infrastructure development at AusNet Services Dennis Freedman said the power lines were lifted using special insulated hot sticks.
“These are specialised poles made from fibreglass that do not conduct electricity,” he said.
“The process is quite quick. In some instances, lines needed to be pulled down and reinstated. This takes a little longer.”
The whole endeavour including permits, transport and reinstatement costs was close to $1 million.
The transformer will lie at the heart of the Haunted Gully Terminal Station and will play its part in distributing up to 530MW of electricity from the Stockyard Hill Wind Farm into the Victorian transmission grid. Once operational, the wind farm’s 149 turbines will generate enough clean energy to power approximately 391,000 homes a year.
“The transformer steps up energy from 132kV, the voltage at which it comes from the wind farm, to 500kV, the voltage at which it needs to connect to the network,” general manager of infrastructure at AusNet Services Ben Woodman said.
“Its capacity is very large even for these voltages; at ~600MVA it is one of the largest in Australia, which it has to be in order to handle the 500MW coming from GoldWind’s wind farm.”
As well building, owning and operating the 132kV dual circuit line and the new Haunted Gully terminal station, AusNet Services’ scope for the transmission assets includes a cut-in to the existing 500kV line between Mortlake and Tarrone.
“It is quite a long process that involves finding a suitable route taking into account such factors as local community impost, cultural heritage, flora and fauna issues,” Mr Freedman said.
“Design is then completed and post permitting, construction begins. This involves pouring concrete foundations of up to 8m in depth and 2.4m wide. Once these are cured, the three- or four-piece poles are erected using cranes. Then the conductor is strung utilising specialist crews and equipment.”
Once complete, AusNet Services will operate and maintain the assets, which will involve day-to-day activities to operate the site as well as medium and long-term strategic asset management activities to optimise the life cycle of the assets, with targeted refurbishments and replacements.
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“It’s a significant asset for AusNet Services with the key considerations relating to safety, security and the technical effectiveness of the station,” Mr Woodman said.
“Our delivery partners Zinfra are constructing the station and lines on our behalf.”
Mr Freedman said the successful delivery of this transformer marks a huge milestone for one of Australia’s largest renewable energy projects.
“It’s a great achievement for the AusNet Services team and we want to thank everyone involved. In many ways this delivery represents the project as a whole – the importance of great relationships and successful collaboration with our delivery partners and the client,” Mr Freedman said.
The transformer delivery to Stockyard Hill Wind Farm sets a precedent for the delivery of the transformer for Dundonnell wind farm, which will be of a similar size, giving the AusNet Services team a solid understanding of what will be involved.
The Stockyard Hill project is one of a number of renewable connection asset projects that AusNet Services has been contracted to build, own and operate.
AusNet Services recently completed building connection assets for two similar projects at the Salt Creek and Crowlands Wind Farms, and are currently building the connection assets for the Murra Warra, Bulagna, and Dundonnell wind farms.
“There’s a solid pipeline of further projects as Victoria makes great strides in transforming to a renewable energy future,” Mr Woodman said.