As more and more countries in Europe and North America commit to net zero, a key strategy is replacing old fossil fuel-driven forms of power generation and replacing them with renewable energy, such as wind turbines and solar panels. The wind industry has seen a particular boom, with tens of thousands of new turbines installed every year across the globe.
However, like any other heavy machinery, wind turbines can catch fire due to mechanical or electrical failures. These fires can have impacts beyond the turbine if there is secondary fire spread to surrounding lands, resulting in potentially catastrophic loss. Without this technology in place, a single fire could cost $7-8 million and cause substantial downtime. The time is now for the industry to use all available technology to prevent these incidents and reduce the risk of fires spilling into the environment.
How do wind turbine fires start?
Wind turbine fires can catch fire due to external causes, such as lightning strikes, or internal causes, such as mechanical or electrical failure resulting in sparks or heat in the nacelle. Most nacelle fires start at one of three points of ignition – converter and capacitor cabinets, the nacelle brake, or the transformer. Nacelle brakes are used to stop the turbine’s blades from spinning in an emergency.
Converter and capacitor cabinets and transformers are necessary for the turbine to generate power and transform it into a voltage that can be exported to the grid. An electrical fault at either location can produce arc flashes or sparks, which can ignite nearby Class A combustibles, like cables, plastics, or fiberglass.
Nacelle brakes are used to stop the turbine’s blades from spinning in an emergency. The brakes can cause turbine fires, albeit due to sparks from mechanical stress and friction rather than electrical failure. While some turbines have been designed with safer, electrical brakes, mechanical brake systems are often used as a backup in the event of power or control failure.
These ignition points are all necessary for the safe generation of electricity from the wind, and cannot simply be designed out. As such, wind farm owners and operators must be ready to deal with fires when they spark.
Why are wind turbine fires hard to fight?
Modern wind turbines often exceed 250 feet in height, while most ground-based firefighting can only reach up to 100 feet. A team sent up-tower to manually fight the fire would constitute a major health and safety risk, as turbines have limited space and escape routes – putting employees not only in direct contact with fire but at risk of being in the turbine if it collapses.
As such, when turbines catch fire, they are often left to burn out, with firefighters’ efforts focused on preventing the spread and clearing the area as fiery debris falls. This results in irreparable damage to the turbine, necessitating its replacement.
What is the cost of a wind turbine fire?
The cost of replacing a burned-out wind turbine depends on a number of factors. First and foremost is the size and initial cost of the turbine. Turbines with more than 3MW of rated capacity can cost between $3-10 million to install during development. Replacement turbines can often cost even more, as manufacturers are likely to charge more for individual, one-off installations. Another key loss is business interruption, or how long the turbine was offline – and therefore not generating revenue.
The average loss due to a turbine fire was estimated by insurance company GCube to be $4.5 million in 2015. As turbines have grown larger and therefore more expensive to replace with greater losses in revenue, we expect a fire to cost anywhere between $7-8 million for new models.
How can turbine owners and manufacturers manage fire risk?
Firetrace’s system is designed with flexible Heat Detection Tubing, which ruptures in response to extreme heat or open flame Turbine manufacturers are already taking steps to “design out” fire risk in turbines. For example, lightning protection systems on turbine blades safely re-direct the surge of electricity away from cables, while condition monitoring systems can identify whether a component is overheating and likely to catch fire.
In order to put out any turbine fires that do start at their source, turbine owners and manufacturers can install automatic fire suppression systems at common points of ignition. Firetrace’s system is designed with flexible Heat Detection Tubing, which ruptures in response to extreme heat or open flame, releasing a clean suppression agent precisely at the source of the fire before it can spread.
Wind farm owners who have taken a more proactive approach to manage risk via fire suppression systems have been able to snuff out fires before they can spread throughout the turbine or into the environment. By investing in the latest technology for fire suppression, owners and operators have avoided the worst-case scenario, saving millions in operating costs.
