Wind turbines take a hammering from the elements and as they age things can go wrong. Fire is a rare risk that plant owners need to take seriously, writes Jeremy Chunn.
Wind turbines are firmly rooted in the grid as technology Australia can depend on, supplying 12.5 per cent of energy in the National Electricity Market in 2022. As they proliferate and age, with electrical storms whirring overhead, wind farm owners must not ignore their duties.
Fires in turbines are rare, but they are more common than the public might imagine.
“The number one thing in the [wind] industry up to 10 years ago was to never, ever discuss a thermal event [fire],” says Ross Paznokas, global head of business development at Arizona-based fire protection company Firetrace International.
He knows this because he worked for a major turbine manufacturer for more than a decade before commencing at Firetrace, which sells fire-stanching technology deployed in wind and solar farms, battery systems, industrial processes and military applications.
Wind turbines look graceful, but they transform enormous amounts of kinetic energy into electricity. They are also sitting ducks in lightning storms so fires can happen.
In January 2023, fire destroyed the nacelle and two blades of one of the 33 turbines at Cathedral Rocks Wind Farm in Port Augusta, a 66MW project in South Australia completed in 2007.
Also in January, a turbine at Cullerin Range Wind Farm in the NSW Southern Tablelands caught fire, one of 30 units at the 30MW plant commissioned in 2009.
In 2021, fire damaged a turbine at the 161MW Tararua Wind Farm in New Zealand.
The Firetrace technology sounds simple: a pneumatic tube leading from an extinguisher is run around areas where fire could start. If it gets too hot or if fire breaks out, the tube will burst and pressurised suppression agents – gas or powder – will blast through and quell any conflagration. Systems can also rely on fixed nozzles or high-pressure CO2.
“Every fire starts small, every time,” says Paznokas. “The detection tubing can find, burst and put out that fire at its origin.
“We do it dozens and dozens of times a year [in turbines] that are never in the news.”
A lightning strike to a blade is the most common cause of fires, he says, where leaked hydraulic fluid absorbed into fibreglass over years can leave blades prone to lighting up.
Hydraulics are installed to rotate blades into high winds, but if a turbine is not well maintained, hydraulic systems can leak and fluid will run outwards to the blade tips.
Paznokas says Firetrace’s systems cannot help if lightning ignites a blade that is dirty with chemicals on the inside.
Almost every other type of fire starts in high-voltage electrical equipment or because of a faulty brake system.
“Sparks can fly if pads wear out, like in a car,” he says.
As owners of wind plants slowly understand the value of goodwill and transparency, the more they are fessing up about fires.
Unfortunately, as developers compete in a rapid buildout, the more they are tempted to cut costs. If the plan is to build a plant and then sell it, owners could scrimp on options, including fire systems. Fire suppression is mandated in only a few markets, including Ontario, a province of Canada, and Germany.
“The lion’s share of building codes [around the world] do not require fire suppression,” Paznokas says, speaking to EcoGeneration from Oregon, in the US.
Conscientious owners in for the long haul will choose the option; others will include it ‘after the fact’ if they have lost a turbine to fire at another project.
Firetrace is currently working with the owner of a fleet of wind assets in Australia. Paznokas estimates fire suppression adds less than one per cent to the cost of a turbine.
“A typical installation can be US$10,000 or less for a $5 million turbine,” he says.
It can take up to 18 months to repair or replace a turbine that has been damaged or destroyed by fire. In that time, landowners and project owners may forgo revenue from lost generation.
“Insurance companies insist on a forensic understanding of what happened, and then there is the time to take down a unit and consider buying a new one,” says Paznokas.
Lost generation, clean up and cost of replacement can push total expenditure to $8-$10 million, he says. That’s not so bad when future insurance estimates are magically accurate.
However, premiums for business interruption cover are volatile in a sector where insurers haven’t had much data to work with.
“They have found out time and again they grossly underestimated how much revenue had been lost [when a turbine is destroyed],” says Paznokas.
“They are beginning to understand what the risk is.”
Premiums have risen sharply. Owners who attempt to negotiate insurance costs in line with expectations are being handed policies that do not include lost revenue and clean up.
A risk that was always there now has a dollar value.