No wind farm owner or operator wants to deal with the headache of a wind turbine fire. However, wind turbine fires do occur and can be disastrous. In an unprotected wind turbine, you are likely to have a total loss if there is a fire. When the fire occurs, you must have a plan in place for how to extinguish the fire and then replace the turbine.
Our webinar with DNV GL Principal Wind Turbine Engineer, Sally Wright and Professor of Fire Protection and Safety Engineering Technology, JP Conkwright, covered the topic of wind turbine fire aftermath. These two experts have both experienced the process from investigation to recommissioning of numerous turbine fires.
Common causes of wind turbine fires
To understand how a fire starts, you need to know the necessary components for a fire. This includes the interaction of heat, fuel, and oxygen. According to Conkwright, wind turbines are oxygenated environments, so the primary ignition points are where heat and fuel interact. Fuel includes not only oil but also fiberglass and carbon structures.
The components that catch fire most frequently are transformers, converters/capacitors, the nacelle brake area, and the hydraulic area. Fires occur in about 1 in 2,000 wind turbines. With the number of wind turbines increasing every year, this means there are more fires every year. With a cost of $7-$8 million per total loss incident, it’s essential to have a fire response plan.
Responding to a fire
An emergency response plan is a crucial component for a wind farm to have. Because wind turbine nacelles are 300 feet or more in the air, they are complex and often impossible for firefighters to stop once they start. This response plan helps to prevent damage to the surrounding turbines and land.
Time for fire service to arrive
It can take first responders 30-45 minutes to arrive at a wind turbine fire location because of its remote nature. Fires can become fully developed after just a few minutes from the ignition, so crews often focus on fighting surrounding brushfires as the nacelle fire burns.
Preventing wildfires
Often, wind turbine fires are not limited to the turbine itself. Flaming components can travel miles in the air and start brushfires. If the vegetation on a wind farm or surrounding areas isn’t properly managed, this can lead to a wildfire. There have been a few wildfire incidents in the US, including over 1,500 acres in Texas and 350 acres in Southern Washington.
While not caused by a wind turbine fire, the California Camp Fire in 2018 that resulted in almost $30B in liabilities and a Chapter 11 Bankruptcy for utility company PG&E shows the damaging effects that wildfires can cause.
Stopping the source of fire
It’s not safe for firefighters to climb up a turbine that is on fire, so unless you have a fire suppression system you cannot actively fight the fire. By tripping the circuit breaker, you can limit the fire's energy source, but if the fire is spreading, the flammability of the turbine material makes it is difficult to stop.
Post-fire inspection process
Analyzing data
The first step in a post-fire inspection is to collect the turbine data before the 7-day buffer. This data only takes a few days to analyze but can take months to form an agreement between the various parties involved. Also, it’s important to understand who owns this data. According to Wright, there have been instances where operators were not aware that the owners or manufacturers owned the data.
Loss of production
If one turbine catches on fire, an entire wind farm can be halted for several hours. This can cause a sizable business interruption. Turbines with fire damage can also take over a year to be up and running again. Considering that turbines generate thousands of dollars per day in revenue, it is prudent to get the turbine running as soon as possible.
Additional costs of wind turbine fires
Staff salaries
The procedures after a wind turbine fire can take up a lot of employee labor hours. Not only do you have to pay these employees for non-value-added work, but you are also preventing them from working on other value-added tasks, like preventative maintenance.
Investigations
A fire investigation can be expensive, as each party brings experts to determine the fire's root cause and where the responsibility lies. An investigation can have three or four parties, each with a fire investigator, electrical engineer, and attorney. Fire investigations can cost $6k-7k a day for a few weeks, according to Conkwright.
Dismantling the turbine
The cost of dismantling a burnt turbine can cause sticker shock for some. Even with the best equipment, dismantling can still cost over $600k to complete. If you run into complications, like the nacelle falling, this can become even more expensive and time-consuming. Responding to a fire in an offshore turbine is estimated to be five to ten times more expensive than an onshore turbine.
No economy of scale benefit
The cost of ordering replacement components for one turbine, especially one out of production, can be costly. When turbines are first purchased, many costs are distributed across 50 or 100 turbines. When there is just one turbine that needs a new component or a replacement installation, it is expensive. Also, it is difficult to schedule the production of specific parts because there is a boom in wind manufacturing right now, and producing a legacy part takes away time from other revenue-generating activities.
Insurance
A common belief is that “insurance will just handle it.” While insurance is there to help in the event of a loss, there are many things that will not be included in your policy. Also, after filing a large claim, you can see your rates increase. If one of your competitors files a large fire claim, it can also affect your insurance premiums.
What can you do to prevent fires?
Fires are expensive, time-consuming, and a pain to deal with. Most turbines have fire detectors installed, but what happens when they detect a fire in the nacelle? You can automatically shut down the turbine, but it can be impossible to stop a fire if it has already started unless you have an automatic fire suppression system.
Clean agent automatic fire suppression systems are safe for employees, the turbine, and the environment. These systems detect fires just after ignition and extinguish the fire before it grows large enough to cause damage. Be sure to read how Firetrace systems saved a wind turbine for a major owner/operator.
