Fire is the second leading cause of accidents in wind turbines after blade failure, with the average overall cost of a wind turbine fire being around $4.5m. Given that $112.5bn was ploughed in to wind power globally in 2016, wouldn’t it be prudent to invest a little more of that in fire suppression?
When a fire occurs the typical action is simply to wait for it to burn out. This can cause significant damage leading to thousands of dollars of repair costs, plus revenue losses as a result of downtime. To illustrate, a single 2.5-3MW commercial scale wind turbine is valued at approximately $3-$4m, with the value of the output averaging $2,800 per day. It’s clear, therefore, that the financial impact of even a minor fire, which can still cause weeks of downtime, can be significant – the average total cost of a wind turbine fire is $4.5m.
There are generally three main causes of wind turbine fires: mechanical failure, electrical malfunction and lightning strikes.
A small fire can accelerate quickly in a nacelle that comprises highly flammable resin fiberglass. Internal insulation in the nacelle, which can become contaminated by oil deposits, further adds to the fuel load. Lightning strikes also pose a uniquely high- risk due to both the turbines’ exposed locations and their height; turbines are now being built in excess of 450ft.
Despite the high fire risk in wind turbines, there are relatively few widely reported incidents in the industry. But from discussions with wind farm owners, turbine manufacturers and insurers, it’s certain the losses from fire are much more frequent than publicly documented.
A 2014 report published for the International Association of Fire Safety Science set out to quantify the true number of wind turbine fires and their impact. In the UK, where the report was published, the findings attracted attention-grabbing headlines in major newspapers such as ‘wind turbine fires ten times more common than thought’, and ‘wind turbine fires are hidden peril.’
Since 2011 there have been 36 large wind turbine fire incidents reported in the mainstream media. One of the worst recorded incidents in recent times took place in California in 2012. More than 100 firefighters were required to put out a wild land fire that spread across 367 acres, which could have been far worse if not for a witness. The final report indicated equipment failure, specifically an arch flash, was to blame for the fire.
And just this September in Wyoming in the US, a wind turbine caught fire and caused a wild fire that burned out nearly 1,600 acres. The cause of this particular incident isn’t yet known, but dramatic cases such as these always hit the front page.
In the social media era news travels fast, with traditional media attention amplified by witnesses sharing news online; often videos of burning wind turbines taken on their camera phones. All this has resulted in increased public awareness of wind turbine fires.
You can read the full article, where we discuss risk prevention, methods of fire suppression, and legislature, in Power & Energy Solutions magazine here