Fire Safety Science

Gearbox and Transformer Fires in Wind Turbines - Early Detection and Suppression with Micro-Suppression Fire Systems

March 26, 2024 | Fire Safety Science 

Gearbox and Transformer Fires in Wind Turbines - Early Detection and Suppression with Micro-Suppression Fire Systems

A Silent Threat Within:

Wind turbines are marvels of clean energy generation, but even these green giants are not immune to a silent threat – fire. While uncommon, fires within the nacelle, the housing at the top containing critical components, can have devastating consequences. Among these components, gearboxes and transformers present a particularly high risk. Our SAR and DAR Systems are capable of suppressing imminent flames in these areas, ultimately lowering this risk of extensive fire damage and total destruction of the wind turbine.


Gearboxes: The Workhorses Under Pressure and Prone to Peril

Gearboxes in wind turbines are the unsung heroes, silently transforming the gentle rotation of the blades into the high-speed frenzy that drives electricity generation.  But this vital role comes with inherent dangers.


Immense Frictional Heat: Imagine a car engine running at high speeds for years on end. That’s the kind of stress a wind turbine gearbox endures. The constant churning of gears creates significant frictional heat, pushing the operating limits of lubricants and gearbox materials.


Lubrication – A Delicate Balance: Gearboxes rely on a precise amount and type of lubricant to function smoothly and dissipate heat. However, excessive lubrication can pool in unintended areas, creating potential fire hazards if it comes into contact with hot surfaces. Conversely, insufficient lubrication can lead to overheating and bearing failures, both of which can spark fires.


Bearing the Brunt of the Force: Bearings within the gearbox are under tremendous pressure, constantly supporting the spinning shafts and gears. Bearing wear and tear is inevitable, and a catastrophic bearing failure can generate excessive heat and spew shrapnel, significantly increasing the risk of fire.


Oil Leaks – A Creeping Threat: Like any complex machinery, gearboxes are susceptible to developing leaks over time. A small leak of hot lubricant can go unnoticed for a while, spraying onto hot surfaces like exhaust manifolds or even electrical components. This creates a ticking time bomb waiting to ignite.


Thermal Runaway: If any of the above factors (excessive heat, lubrication issues, bearing failure) are left unchecked, a vicious cycle known as thermal runaway can occur. Heat generation outpaces the gearbox’s ability to dissipate it, causing a rapid rise in internal temperatures. This can lead to the ignition of lubricants, seals, or even the gearbox housing itself, resulting in a fast-spreading nacelle fire.


Transformers: The Power Connectors Under High-Voltage Tension

Transformers in wind turbines play a crucial role, acting as the bridge between the electricity generated by the turbine and the power grid. They take the relatively low voltage produced by the turbine and “step it up” to a much higher voltage suitable for long-distance transmission. However, this vital function comes with inherent fire risks:


Electrical Faults: A Spark Can Ignite: Transformers are intricate electrical components with high currents coursing through them. Unexpected surges, short circuits, or internal component failures can generate sparks or arcing, which can easily ignite surrounding flammable materials like transformer oil or wiring insulation.


Flammable Insulating Fluids: Many transformers utilize insulating fluids to cool internal components and prevent electrical arcing. These fluids, while effective insulators under normal conditions, can become flammable at high temperatures or if exposed to open flames. Common insulating fluids include:


Mineral Oil: The traditional insulating fluid, but it has a relatively low flashpoint (the temperature at which it ignites).


Synthetic Esters: A safer alternative with a higher flashpoint, but more expensive.


Pressure Buildup: A Recipe for Disaster: Transformers operate in a sealed environment, and internal faults or overheating can cause a buildup of pressure. This pressure buildup can lead to a rupture of the transformer housing, spraying flammable oil and creating a fireball effect that can quickly engulf the nacelle.


Domino Effect of Destruction: A fire originating in the transformer presents a serious threat because of its proximity to other critical components in the nacelle. Flames and heat can easily spread to nearby wiring, hydraulic lines, or even the gearbox, resulting in a much larger and more difficult-to-control fire.


Why Quick Response Matters in Wind Turbine Nacelle Fires

A fire within a wind turbine nacelle is a nightmare scenario, posing a triple threat to finances, clean energy production, and the environment. Here’s why early detection and suppression are critical:


Devastating Costs: Statistics paint a grim picture. While uncommon (around 1 fire per 100 turbines over its lifespan), a single fire incident can result in millions of dollars in damage, according to a GCube report from 2015. With the increasing size and complexity of modern turbines, this cost is likely to have risen significantly. Replacing a damaged nacelle can easily reach $9 million or more depending on the size and capacity of the turbine.


Lost Green Gigawatts: A burning turbine isn’t just a financial burden – it’s a lost opportunity for clean energy generation. Downtime for repairs can stretch for months, impacting project profitability and jeopardizing clean energy targets.  Considering the growing focus on renewable energy sources, these lost megawatt-hours can have a significant impact on overall clean energy production.


Environmental Fallout: Beyond the immediate financial losses, nacelle fires can have a devastating impact on the environment. Damaged gearboxes often contain lubricants, which can spill into the ocean in the case of offshore turbines. This oil spill can harm marine life and disrupt delicate ecosystems. The environmental cleanup costs associated with such spills can further exacerbate the financial burden of a fire incident.


Micro-Suppression Systems: The Tiny Titans Taming Nacelle Fires

Strategic Placement:  Both FireSci’s SAR and DAR systems utilize a network of small-diameter heat sensing tubes strategically placed near high-risk components like gearboxes and transformers. This targeted approach minimizes the amount of clean agent used and potential damage to unaffected equipment.


DAR (Direct Agent Release): When the pre-set temperature is reached, the tube ruptures, directly releasing clean agent to extinguish the fire at its source.


SAR (Secondary Agent Release): The ruptured tube transmits a signal to the control panel, triggering the release of clean agent through pre-installed nozzles specifically positioned around the high-risk area.


This rapid response, in milliseconds for DAR and slightly longer for SAR, minimizes fire damage and potential escalation.


Compact and Efficient:  Nacelles have limited space.  Micro-suppression systems, with their small footprint and lightweight design, are a perfect fit.


Simplified Maintenance:  Unlike traditional systems, these micro-suppression systems require minimal maintenance, keeping downtime for wind turbine operations to a minimum.


Clean Agent Technology:  Both SAR and DAR utilize environmentally friendly clean agents (FK-5-1-12 or HFC227ea) that extinguish fires without leaving harmful residue, protecting sensitive electronics within the nacelle.


The SAR and DAR Advantage:


By offering the choice between the rapid, direct response of DAR and the more controlled, targeted approach of SAR, we provide a versatile solution for various nacelle fire scenarios.



Gearbox and transformer fires pose a significant threat to wind turbine operation. By implementing micro-suppression systems specifically designed for these high-risk components, wind farm operators can ensure early detection and suppression, preventing catastrophic fires and safeguarding their valuable assets. Investing in micro-suppression systems offers peace of mind, protects your investment, and ensures the continued clean energy production of your wind turbines.

We specialize in the production of automatic fire suppression systems designed to ensure the safety of various assets and industries. Our commitment to protection is at the core of our solutions, providing a reliable guarantee for safeguarding your assets.

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