WHAT are the fire risks with wind turbines?
These structures are increasing in number across the country.
In Western Victoria, this is at a great rate due to the Allan State Government’s designation of this part of the state as a renewable energy generation zone.
There are currently about 4000 turbines in Australia – a figure likely to reach about 11,000 by the year 2030 – before moving onward and upwards to some 51,000 by 2050.
They carry significant quantities of oil for hydraulics and gear boxes, with volumes often well in excess of 1000 litres, depending on the capacity of the generator.
This is conveniently stored on top of a steel pylon at over 100 metres above ground level, being housed in a fibreglass box delicately named as a ‘nacelle’ (a skiff or small boat in Old French).
It is well known that wind turbines can catch fire.
But how often does this occur, what are the causes and what are the consequences?
Frequency of fires
IT has been estimated that, worldwide, about one in 2000 wind turbines catch fire annually.
This figure has decreased somewhat from one in 1710 estimated in 2011 by The Caithness Windfarm Information Forum (CWIF), an organisation based in Caithness, Scotland, dedicated to monitoring and disseminating information about wind farm developments and associated issues.
This suggests that one can expect about two turbine fires per annum in Australia at present which might rise to five or six in 2030 and to 25 in 2050.
However, these rates will probably decline as fire prevention measures improve.
Two turbine fires were reported in the financial year ending June 30, 2024.
The most recent of these occurred in Victoria occurred on June 28 at the Cape Nelson South Wind Farm near Portland.
This resulted in the destruction of the turbine and ignited approximately 30 hectares of surrounding grassland.
Investigations into the cause of the fire are ongoing, with agencies such as Energy Safe Victoria and WorkSafe involved.
Prior to this, a wind turbine fire was reported in August 2023 at the Yambuk Wind Farm, west of Port Fairy.
Firefighters responded promptly, and the fire was brought under control without significant spread.
Thus, one can see that fires are not everyday occurrences, but they are a clear and increasing problem.
The causes of turbine fires
RESEARCH undertaken by Fei You and others including Monash University’s Md. Rokonuzzaman and Wen Shan Tan found that there was a fairly even distribution of causes of fires.
The failure of machinery or electrics, poor maintenance and, lightning strikes all contributed, with only 10 per cent of fires being due to other (unspecified) causes.
The amount of combustible material in a turbine’s nacelle is essentially limited to the oil and the polymers in the fibreglass walls.
The turbine’s blade exteriors are also fibreglass, but the core is foam or balsa wood - which are both flammable.
Mechanical, maintenance and electrical failures can be reduced, but it is fair to say that they are never going to be completely eliminated.
Lightning will always be with us and despite the best lightning precautions, 20 per cent of turbine fires have this as their cause.
As with aviation over the decades, safety will probably improve but the risks will never be completely cancelled.
The consequences
A TURBINE fire is a significant loss for a power company and its insurers, but a potential catastrophe for a rural community.
Because of its elevation and the available fuel (oil), a bad turbine fire becomes torch-like and has the ability to ignite grass and bushfires with ease.
Not all turbine fires are like this, and many have the damage confined to the individual generator and, possibly, the rotor and pylon.
However, incidents such as that at Bridgewater earlier this year can easily ignite a major fire.
The Bridgewater event burnt 30 hectares in midwinter close to the coast.
Imagine the same glitch at a Melville Forest turbine on a 43-degree February day with a howling north-westerly…
As a shampoo advertisement said; “It won’t happen overnight but it will happen.”
