In short:
The Clean Energy Council says there are options for old wind farms as the originals approach the end of their life expectancy.
Most parts of a wind tower can be recycled but there are limited options for turbine blades.
What's next?
Engineers are working on creating turbine blades that can be recycled.
What happens to wind turbines when they reach their use-by date?
It's a question that has become more pertinent as Victoria's first wind farms approach the end of their 20-to-30-year life span.
State government figures show there are 41 wind farms and about 2,500 turbines in Victoria.
Among the oldest sites is Codrington in south-west Victoria. It opened in 2001 as Australia's first commercial wind farm.
Challicum Hills, near Ararat in the state's west, was completed in 2003 and Yambuk wind farm in south-west Victoria opened in 2005.
The Clean Energy Council's director of energy generation and storage, Nicholas Aberle, told ABC Radio Ballarat no commercial wind farms had reached their end of life or been decommissioned so far in Victoria.
He said most agreements between wind farm companies and landowners hosting wind turbines included requirements and funding agreements for the decommissioning process.
Mr Aberle said planning permits and approvals required decommissioning plans.
These might not spell out every detail at the time but there was always an agreement with landowners on how decommissioning would work.
Mr Aberle said wind was an infinite resource, unlike other energy sources such as underground mines, which would decline in value once the materials were extracted.
He said the Clean Energy Council outlined options for a wind farm with aging turbines.
A wind farm operator could decide to dismantle the farm or erect new turbines if the landholder agreed. There was no risk of wind farm operators abandoning old infrastructure, Mr Aberle said.
One factor in this, he said, was the highly valuable materials in turbine towers, including steel, copper and other precious metals in the generators.
"The overall cost of decommissioning is not that big once you factor in the money that the companies will make from selling that scrap metal," he said.
Scrap metal recyclers ready
According to a 2023 report by the Clean Energy Council on wind turbine recycling and decommissioning, old wind turbines could contribute about 47,000 tonnes of scrap metal to the waste stream.
This equalled less than 1 per cent of the total amount of scrap metal recycling in Australia, the report said.
Melbourne-based scrap metal recycler Norstar is one company in Victoria with the capacity to recycle wind turbines.
The company handles steel, copper, brass, aluminium and other precious metals.
Norstar director and trading manager James Saliah said the company had not handled much wind infrastructure but he expected that to change as more turbines reached their end of life.
And he said the local industry had the capacity to handle demand if it ramped up.
"There're plenty of these turbines around now so I would assume the demand would increase," Mr Saliah said.
About 90 per cent of a wind turbine can be recycled. The towers of steel and other metals are recyclable but the turbine blades are more complicated.
Turbine blades are mainly made of fibreglass and carbon fibre or expoxy with very limited end-of-life options for composite materials.
According to a Clean Energy Council report, decommissioned wind farms would create an estimated 15,000 tonnes of blade composite waste by 2034.
The report said there were few feasible or commercially competitive blader recycling options at this point.
But Mr Aberle said the industry was working to change this.
"We don't have all the answers, but there's a lot of research going on and [engineers are] developing new blade technology so the new blades on new turbines are more recyclable," he said.