Getting a new turbine for your home can be a rewarding investment. Most people would often go through all pros and cons, risks, and benefits in great detail before putting their hard-earned money into a turbine. One of the major concerns that many people have is the risk of fire in the wind turbine. We have deeply researched this from reliable scientific sources, and here are the things we found
Can wind turbines catch fire?
Yes, wind turbines can catch fire as they contain several flammable elements. However, the incidences of turbines catching fire are very rare.
A fire in a wind turbine system is economically catastrophic. In most cases, fires cause significant damage.
Fires are the second biggest risk for the turbines right after blade failure. A study by Caithness Windfarm Information Forum (CWIF) analyzed the top causes of accidents for the turbines
- Blade failure – It accounts for 19% of incidences
- Fires – They are responsible for 15% of accidents
- Structural Failure – these cause 9.7% of the reported accidents
How often do wind turbines catch fire?
One in 2000 turbines in the world catches fire each year. This includes older turbines with low fire protection and newer ones with higher levels of protection. The incidences of fire are significantly lower in the latest models.
When we look at the data, we see it is often tainted with a lot of bias. Anti-wind power companies put it way higher, and wind power companies put it lower.
According to CWIF, there have been 200 reported incidences of turbine fires between 1995 and 2012. That means 11.7 fires per year
However, the International Association for Fire Safety Science (IAFSS) report said that about 91% of the wind turbine fires are not reported and therefore not mentioned in the reports. It claimed that 1500 turbine fires occurred between 2006 and 2010. For the same period, CWIF put the numbers at 142. So, it’s evident that there is a considerable deviation between the two sources
To resolve this confusion, we decided to go deeper analyzed these reports in detail.
According to the director of Renewable Energy UK, Chris Streatfeild, the numbers mentioned by IAFSS are “Incidences” and not “Accidents.” You must be thinking that what’s the difference between the two? Incidences include everything minor slips, trips, and actual Accidents.
According to him, most of these incidences were minor where there was no injury, harm or damage happened.
So now, data from both sources makes a lot more sense. CWIF mainly mentions accidents with significant damage, while IAFSS talks about both major and minor incidents. The discrepancy resolves into a conclusion that there are ten times minor incidents compared to the major incidents.
In 2012 there were 225,000 turbines installed in the world. So if you consider the figure of 11.7 fires per year, there was one fire per 19230 turbines per year. That is significantly lower than other sources of energy like fossil fuels which are responsible for thousands of fires in a year and cause much more damage.
Why do wind turbines catch fire?
Now we know the frequency of fires, the next big question that most people ask is why do the turbines catch fire in the first place.
Every fire needs three main things to start; oxygen, fuel, and ignition. If you have ever looked at a turbine closely, you will know that it has plenty of all three.
- Oxygen: Wind turbines are installed in areas with plenty of Wind, and what does the Wind have? Oxygen! Once the fire starts, high-speed winds hasten its spread.
- Ignition: A fire cannot start without ignition. In the case of a turbine, this comes from three primary sources.
1. Electric – a turbine system contains capacitors and convertors. These parts can generate sparks in case of a malfunction
2. mechanical – mechanical parts generate heat because of friction which can start the fire
3. lightning – Turbines are large structures and attract lightning. Lightning is the leading cause of turbine fires
- Fuel – Turbines contains flammable materials like polymers and oils that can sustain fires
Vulnerable areas
To understand turbine fires, we need to understand the vulnerabilities that are responsible for these accidents.
- Convertor Cabinets and Capacitor Cabinets: Electric failures can happen from short circuits, generator failure, cable failure, etc. One of the parts which are most vulnerable to this is convertor cabinets. Convertor cabinets convert direct current to alternate current and vice versa. These cabinets are usually located in the nacelle, which is the outer casing of the turbine.
The nacelle is made of flammable materials. The fires that start in the cabinets can quickly spread to the nacelle. Once that happens, the entire nacelle catches fire which spreads all over the structure. A nacelle is located at a significant height, making it hard for the firefighters to do anything. In 90% of cases where nacelle catches fire, the turbine is wholly ruined.
- Nacelle Brake: It is situated behind the gearbox and is also susceptible to fire. These brakes help in stopping the blades in an emergency. In this process, a lot of heat is generated due to friction that can cause fires. The good news is that in the latest turbines, electrical brakes are less prone to fires. However, mechanical brakes are still employed as backups for electrical brakes.
- Transformer Fires: Transformers convert the energy into desired voltage for the electric grid. These are generally located in the nacelle or the base of the turbine. Just like cabinets, electrical faults in the transformers can cause fires. Some transformers may also contain highly flammable oils. Popular to contrary belief, this is not the most vulnerable part. It ranks third on this list.
How can you prevent it
So now we know all about turbine fires, why they happen, and how often. Now we need to understand how these can be prevented and convert turbines into safer options.
Fire Suppression Systems
These are designed to prevent the spread of fire throughout. These systems hold back the fire until firefighters arrive. They are designed to reduce losses as much as possible. Fire suppression systems are usually sprinkler-based or dry chemicals-based.
These systems can either have active detection, which requires electricity, and non-electric systems work without power. These are equipped with a pneumatic mechanism. As the fire comes in contact with the tubing, it bursts and alerts the system of a possible fire hazard, and it releases the fire suppressing ingredients.
The latest fire suppression systems are so advanced that, in most cases, they don’t even require a cleanup!
Lightning protection systems
Lightning strikes can contain vast amounts of charge and can quickly start a fire. Often overlooked, lightning poses a severe threat to turbines.
Lightning protection systems involve grounding the turbine blades and other systems. The lighting receptors on the blades are connected to the blades, which are connected to the nacelle, which further leads to the ground.
Non Combustible oils
Older versions of oils used in the transformers were mostly flammable and caused disasters. Now many variations of oils are out there, which are non-flammable and work just as well.
Final Thoughts
The fire risk for a turbine system is very low, and it is even lower in the latest versions. With highly effective methods to avoid fires, turbines are a pretty safe investment. Also, there are new and stringent guidelines that manufacturers have to follow. These guidelines put tremendous stress on fire protection.