150 - Wind Turbine Fires with Guillermo Rein

0:00 Hello everybody, welcome to the FarSense Show, episode 150. Wow, the time flies by so fast. I've just recorded the episode 100 and it seems to be a year ago already. As you hear this broadcast, I'm somewhere in the world enjoying my hot end vacations. But as they say, the show must go on. So here we are with this hopefully lovely episode, and I've invited the guest with whom it all started, with Professor Guillermo Reyn from the Imperial College London. I've let Guillermo pick the topic for this episode and he chose to speak about wind turbine fires. A very interesting topic, perhaps an overlooked problem in the world of engineering, perhaps not a big deal, certainly something we have a problem with deciding if it is a problem or not, because the industry is not really helpful, as in engineering fire safety of those devices.

0:55 It's kind of an interesting problem of how to prevent the fires, how to mitigate the consequences of the fires. What can you do inside the wind turbine? Because you can imagine they are pretty remote and not very well accessible. So in case of a wind turbine, if there's a big fire growing inside, there's not very much things you can do. So well, fire safety engineers know their craft. They can create fire safety solutions for devices like this, but they have to be allowed to do that and, in some way, the industry is not really looking for that help, and that gives this episode, this discussion, an interesting twist.

1:38 So, yeah, I think it's going to be a very interesting episode for you all. So please let me invite you, together with Guillermo Reyn for this episode on wind turbine fires. Welcome to the Firesize Show. My name is Wojciech Wigrzyński and I will be your host. This podcast is brought to you in collaboration with OFR Consultants. Ofr is the UK's leading fire risk consultancy.

2:21 Its globally established team has developed a reputation for preeminent fire engineering expertise, with colleagues working across the world to help protect people, property and environment. Established in the UK in 2016 as a startup business of two highly experienced fire engineering consultants, the business has grown phenomenally in just seven years, with offices across the country in seven locations, from Edinburgh to Bath, and now employing more than a hundred professionals. Colleagues are on a mission to continually explore the challenges that fire creates for clients and society, applying the best research experience and diligence for effective, tailored fire safety solutions. In 2024, ofr will grow its team once more and is always keen to hear from industry professionals who would like to collaborate on fire safety futures this year, get in touch at ofrconsultantscom.

3:13 Hello everybody, welcome to the FireSense Show. I'm here today with Professor Guillermo Reyn of the Imperial College London. Hello Guillermo, welcome back to the podcast. Hello Bojie, Good to be back. Thanks for inviting me again. You have a lot of patience. Well, and you have this free ticket thing that you can just redeem whenever you feel like it. So just send me an email and we'll do another one. Anyway, for this episode, you have chosen a very interesting subject to talk, and that is the fires of wind turbines and, in general, wind turbine fire safety. I guess we can place this within the broader scope of renewables, sustainability and fire, a gap that needs to be closed, and when I was researching, I found your paper from Edinburgh Times, published in the IFSS 2014.

4:05 So we're at the 10th anniversary of your paper. Has much changed since then? The topic, no, has not changed for bad reasons, but the fascination has not changed either. It is a very interesting topic. It's a new hazard I'm a mechanical engineer. I'm's a new hazard having wind turbines. I'm a mechanical engineer, I'm obviously fascinated by wind turbines, All turbines, yeah, and it's for wind, which is important for you, Bocce, and it provides energy and is renewable and is literally you cannot get better. But I'm a forest scientist, I'm an engineer. So at some point when we were in Edinburgh, we got in the news this fascinating unfortunately fascinating images of a wind turbine on fire.

4:47 You know, it's fascinating, in particular because the smoke becomes a tracer. You can actually visualize the flow of the wind turbine in the wake. So we wonder is this one-off or this happens with more frequency? So we got two students, two master's students, for the IMFSE At that time I was in Edinburgh so I could supervise them and we got two of them and we got together with Ricky Carville and David Lang and the team. The five of us did the study. What we found is that we were the first ones, as scientists, to look into the problem. We found that the data existed a little bit. What we found is that we were the first ones, as scientists, to look into the problem.

5:31 We found that the data existed a little bit. We found that there was some knowledge of why these fires were happening. We saw knowledge of the frequency of them and, obviously, as engineers, we immediately identified the ways to address them. And that was when the students graduated and they went to work for industry. And then we polished the paper. So you said you were looking into the problem based on a single off incident that triggered I think I know which video you refer to because it was quite viral. Perhaps many of them were viral with this beautiful circles of smoke leaving the burning turbine leaving the burning turbine. And obviously since then I think I've also been, at least I've been noticing, you know, those fires in the media and they seem to happen every now and then.

6:13 Do we have an estimate of how big problem is that overall? Like, how often do those fires happen in the industry? Yeah, so I'll tell you, I'll answer that question, which is the single most important question in the topic. I'll answer it in three parts. The first part is I think, in spending some time into this, that these fires are rare and they are not the end of the world and it is not the end of the wind turbine industry. Okay, that's the first answer. The second answer is when we look into the data we do see about, for example, when we did our team did the analysis we saw about one every 10,000 turbines, one fire every 10,000 turbines, which is literally you can just neglect it.

6:59 When other people have done the studies, they have found one every 2,000 wind turbines. That starts to become a little bit too close to comfort. When other people have done the studies, they have found one every 2,000 wind turbines. That starts to become a little bit too close to comfort. One in 2,000, take into account. One turbine is about $2.5 million US dollars and every year that they are operating they produce half a million US dollars operations. So when you lose a turbine you lose your initial investment, but you also lose a lot of money every year that this turbine is not producing anymore. So having one fire every 2,000 turbines is uncomfortable, but we didn't see one every 2,000. We saw one every 10,000. And that number is much more easy to manage.

7:41 And the third part is I should not be answering this question. Part is, I should not be answering this question. Borgio, we should not be answering this question. We are in this role today. We are scientists. It should be the industry who is answering this question. And when we asked industry, they told me, yes, we have the data and no, we are not going to tell you. And then I thought, okay, as a scientist, that's intriguing why they don't want to tell me. But at the same time, they want to tell me don't worry, guillermo, go to sleep, you don't have to worry, it's not a problem. But no, we're not going to show you the data. It's like I'm a scientist. My arguments for me run based on numbers and knowledge and hypotheses and testing. You cannot tell me that's okay, guillermo, go somewhere else, no problem here, nothing to see here.

8:27 That only makes me really wonder what is the number now? And I guess at some point, Boje, someone from the industry, from the one-to-one industry, is going to be listening to this podcast. So I have a message for them Release the data. Find someone that independently will look into your data and will be able to answer this question. When you told me this could perhaps be an interesting topic to talk, first I was kind of like, is it really a good topic for a fire science show? And then, when I was thinking a lot about those wind turbine fires, I think it's a brilliant place where you could really well explain the value of fire safety. You know, because you have a very isolated device, the wind turbine itself, To the best of my knowledge, they would not propagate between the turbines.

9:14 Okay, there's damage to surroundings and we'll probably touch that, but it's not that you have one turbine on fire and the rest of the park will get. And you know how much they cost to build. You know how much they produce per year. You know how much you would like to use them. So loss is like the most you know sharp you could have in fire safety, because you can tell up to like perhaps $10,000, exactly how much this fire has cost, and you can also, perhaps in dollar, tell how much it will cost to provide some. You know equipment that will reduce it. You know so and don't forget, that it's impossible to miss them. We were studying, we found more than 300 wind turbine fires like each of them with a date, a location and a photo and knowledge of it 300.

10:02 And we use social media because of media, because there is no other way. So imagine how difficult it is to hide these fires from happening than even social media reports on them, instead of being the authorities or the owners, or the neighbors. Yeah, I mean it's kind of fascinating. Let's go deeper into this. I'll tell you we learn a lot in this work. We produced the paper that you referred to in 2014, and then we have a follow-up paper in 2021 where we revisit the problem and we continue on this. This was an article, not a paper, an article in the Society of Fire Protection Engineering magazine, but I'll tell you what we found. What we found is I want to highlight this, I don't want to get too excited and get people wrong on this I love renewable this.

10:45 I don't want to get too excited and get people wrong on this I love renewable energy. I support wind turbine industry, but when we learned about wind turbine fires, we realized this was actually the dream of an arsonist. You take flammable materials different ones, some solid, some liquid, multiple of them and you put them in close proximity to multiple ignition sources mechanical and electrical and you put them very close to each other. You put them with plenty of oxygen and wind to make sure that things go you know when they go, they go well and you put them very far away from the firefighters, so everybody can see them, but the firefighters cannot reach them. That is, in a summary, a wind turbine. So the fuels, for example, are the large amount of polymers of plastics that are used in the nacelle.

11:30 There is a lot of metal components, obviously, but there is a lot of composites, there is a lot of cables, there is a lot of insulation. So sorry to interrupt you. The nacelle is the part where the gearbox and generator is hosted and on top of that you have the blades. I hope that's the correct methodology. So if you could go once again like what's inside the nacelle and which parts of that are actually like flammable material, fire hazard potential. So the three main parts of a wind turbine are the tower, which is hollow and there's maybe cables going through it and a ladder to go up. Then the nacelle, which is the big part, which is bigger than I mean.

12:12 It's a multi-story room, it's not a small room, it's a big room. It's called the nacelle, that doesn't have windows and it's just a big block where the engine and all the machinery is inside and then it has the blades which are attached to the nacelle, and inside the nacelle is where you have the gearbox, you have the mechanical elements, you have the electrical generator and then you have the cables and the controls, and the cables that go down to carry the electricity that has been generated in the nacelle Is the electricity converted already at the level of nacelle or it's a separate thing on the ground? Inside the nacelle. Inside the nacelle is where the energy is converted from mechanical in the shaft of the blades, is converted into electrical energy with a generator.

13:04 I meant more like a transformer station where you would convert the voltages, but that's probably not the story. Yeah, no, that's true. It has a little bit of a transformer to control the quality of the signal at source, but that is something that typically is done at the farm level, not at the cell or turbine level, and which parts of it are combustible. Out of them. Absolutely, I mean literally no, a nacelle is. I mean to give you an idea. A nacelle would be almost like a flat, a two-story flat, london style. Um, it's completely full of stuff. It's very warm. The nacelle, when it's been operated for a very long time, as it's meant to be, becomes a very warm environment.

13:49 There is heat that is being released inside by multiple reasons and it's very noisy and it's full of electrical parts and mechanical parts. So it's a dangerous place. It's not a place for anyone to be, fascinated for an engineer, unpleasant for other people, and there is a very large amount of polymers, plastics, inside a nacelle. The shell of a nacelle typically could be, and it is now made of composites which has a level of flammability. There is a lot of cables, many hundreds of meters of cables, which the insulation of the cables is made of polymer plastic. The insulation of the cables is made of polymer of plastic and it has insulation for heat transfer and for sound of different components and different parts of the nacelle that's also flammable.

14:31 And then it has oils oils for the friction of mechanical parts, oils for insulating the electrical parts for the transformer, etc. And a great majority of these oils not all of them are flammable as well. And what about the blades? Like, are blades flammable? I'm pretty sure yeah the blades are made of very light, composite, very light, very strong, very large composite components and they are flammable. It doesn't happen frequent that the blades themselves get on fire. What happens more frequently in a fire is that then a cell gets on fire, but the blades themselves can also burn, and there are images of blades burning and spinning at the same time, which is a weird image.

15:13 So if you look at those fires in the wind turbines, it's not that it's a very tiny fire. It went down on its own. Usually they would propagate and if they did they would have consequences probably fatal to the entire building. I wondered, like how many fires grow to a size where they are actually like destroying the entire turbine? So what we saw in the data is when there is a fire in a wind turbine, it most of the time 90% of the times it leads to the complete loss of the nacelle. So there's no way you can repair. You had a fire, you lost the nacelle, that's it. And then two things can happen.

15:54 One is that it burns out and you lost the nacelle and you have to put a new nacelle, or the owners have to put a new nacelle and that's it, and it's only an economic concern of that specific investment. People might have seen it, my team might have seen it, maybe my team didn't see it. The other thing that can happen is that the fire starts to burn and it starts to throw debris metallic and otherwise pieces of plastic that are burning. They fall on the ground. They ignite what is called a secondary fire. This is more concerning because a secondary fire could actually go much further away than the single nacelle and, in principle, the responsible person would be the owner of a nacelle.

16:38 And this has happened. About 10% of the cases that we saw I highlight that we saw, because the industry doesn't see the data 10% of the cases that we saw led to secondary fires. Some of them were burning the grass around the farm. Some of them were burning the factory where the nacelle was. Some of them were burning nearby infrastructure. So secondary fires is a concern because it is difficult to deny where the ignition source was. Is it like an effect of parts of the blades flying away at large distances, thrown away by the rotation, or more like a firebrand stuff caught by the wind? My imagination is going quite crazy about throwing big chunks.

17:24 That would be a huge firebrand they already fall far without the need of the centipugal acceleration of the blades turning. The blades burning it happens very rarely. I would say blades maybe is actually about 5% of the fires in a turbine, but the production of firebrands is always every single turbine. Fire produces firebrands. There are pieces of different things that are burning and they start to go. You know a high altitude with wind, so they can actually fire hundreds of meters away. And this is despite that. Every wind turbine farm protects the immediate vicinity. They're aware of, for different reasons, that they should clear the grass and they should not have flammable things next to the tower and even doing this, 10% of the fires lead to secondary ignitions.

18:15 In your SFP Europe paper I read the mention about a fire that happened in Riverside California. A fire that happened in Riverside California, so perhaps you can bring it up to the listeners to show how this can spiral up a little bit. Yeah, so this is just one of them. If we saw 10% of them, we saw literally about 20 or more, or we studied fires that led to secondary ignitions. But this happened in California, I think it was in Riverside. I have not immediately surrounding the tower, the turbine, because that grass had been removed, rightly so. It went to the farther away.

19:01 So it means that the firebrands were reaching unexpected places for the owners. The owners were caught by surprise and it led to the burning of a nearby forest. It led to almost four kilometers square of forest burning, which is, I mean, it's a small wildfire. For wildfire scientists we're talking about much bigger wildfires, but taking into account that it was undeniably who was the ignition source, this, in the US, is very important because the ignition source in the US pays all the consequences of what happened. So the owner of this wind turbine had to pay for this, for the expenses of the cost of the damage that he had produced and if he had gone wrong, imagine that this was not a small wildfire.

19:47 Imagine that this happened on a windy day, not too windy that you have to turn it off the wind turbine on a decently windy day in the summer. California, beautiful place I've lived there where the vegetation is dry, so maybe there's a heat wave, and then, instead of a few kilometers square, we start to talk about dozens of communities having to evacuate, and then people start to pay more attention. Unfortunately, when these bad things happen, then people start to pay more attention. Unfortunately, when these bad things happen, then people start to pay more attention. Okay, another thing that we have not touched yet is the ignition. In many fire considerations, media would usually focus on what was the cause of an ignition.

20:28 For us, it's just one part of the switch that we try to solve, but do we know the typical causes of ignition in such devices? Yeah, there are many different reasons for ignition. When we look into the data, the leading cause of ignition is lightening strike. Okay, which is funny and not funny because all wind turbines are already protected against lightening strike. So, if they're already, because you don't want an electrical signal, artificial signal, going into the turbine. So if you protect them against lightning strike, and still this is the leading source of ignition, it means right power engineers are needed for sure.

21:10 The other reasons were mechanical hotspots. So the maintenance of a cell for whatever the reason, is not as good as it should be, or maybe there are mechanical defects. Then mechanical parts that are in contact with each other, maybe in the gearboxes or maybe in the shaft, they start to heat up. We use hotspots because we are surrounded by seals, liquid and solid, and the hotspots become an ignition source. And the third reason is electrical arch, which is when some of the electrical elements they are not isolated from each other. It creates an arc and then the arc is a beautiful, unfortunately ignition source for flammable elements that might find in the vicinity of it.

21:52 But from the statistic majority of lightnings right. The leading cause when we look from the statistic majority of lightnings right the leading cause when we look into the data, was lightning strike. It really caught our attention because every single wind turbine since they were invented obviously are protected against lightning strike because they are like begging for a strike, the leading cause of fires. Even if you were to design them better so that lightning strike doesn't become an ignition source, we still to design them better so that lightening structures can become an ignition source. We still have to deal with two other very different ignition sources the mechanical and the electrical. So this is a fantastic problem for a fire scientist because you have multiple fire problems, not just one, and then you bring something and it's solved. It has multiple things that is needed that the designers and the owners need to understand multiple things that is needed, that the designers and the owners need to understand.

22:40 One thing that makes me curious do those challenges scale up with the size of the turbines? Because we also know that the turbines are growing, and especially the turbines installed overseas. So there's a big wind farm project in Poland and those are some massive, massive turbines, not like anything I've seen on the ground. So I wonder, is there a difference based on the size or just like? Well, if nothing else, I mean the thing is, every wind turbine is evolving. The technology is evolving in size, but it's also evolving in type of technology and material, so it's very difficult to compare. Then, as you make the wind turbine bigger, you're bringing more fuels. It's interesting that the you're bringing more fuels. It's interesting that the industry is not bringing less fuels, it's bringing more fuel in the sense I mean something that is flammable fuel.

23:22 As for a fire engineer, and as you increase the power, you increase the strength of an arc, you increase the strength of a mechanical failure. So as you make it bigger, you bring the hazards developed in size to be bigger and the loss is bigger. It's not the same losing a cute small 1 megawatt turbine than losing one of these monsters, which they have now, of 10 megawatts. The economic loss and the amount of debris they will produce as firebrands it is much bigger as the wind turbines grows. Hopefully, the ones installed at the sea will not cause a secondary fire.

24:02 It would be interesting, though, if it hit a ship nearby. That would be very bad luck. I can imagine such a scenario, though. No, but you know what is the problem with the ones at sea. It's actually fascinating, but all this is not that you can go into a textbook or there's a little manual, all these. I had to scratch it from different people that I've been meeting for the last 10 years, each of them giving me a piece of information and then getting it together. It's evacuation. The turbines in the sea are visited for maintenance by technicians way more often than the ones inland, and when they visit, they stay there for longer. Sometimes, actually, they have to sleep overnight several days while they fix the issue at sea.

24:45 If you have a fire in the wind turbine while there is people in the nacelle, it is a very dramatic situation because they are rarely designed for evacuation situation because they are rarely designed for evacuation and unfortunately, there have already been fatalities of technicians that were in the wind turbine when the fire happened. This is something that industry said this will never happen. It's so infrequent. It's so infrequent. Well, unfortunately it happened, and the only time that I've seen the industry in more than five minutes of attention to fire safety was actually, unfortunately, when these two people died in the Netherlands. I think it was in 2014,. I think it was. For sure it's not a space designed for escape and for sure I mean based on my general knowledge in buildings and building systems.

25:31 While ongoing maintenance is much better chance to get a fire than in normal operations, I mean there are hot works done. Actually, yeah, yeah, yeah, that was the fourth reason. The easier to handle is hot works, which is you have technicians doing something soldering or welding, or they're putting asbestos or something, and they themselves become the ignition source. That's the fourth. That's the easiest to handle, okay. We know why they burn they have flammable materials and they are isolated, and they're a nice place for fire to grow. They have some ignition sources more than sufficient to set the thing on fire.

26:11 What can we do about the fires? It's quite fascinating, isn't it? So are they even equipped with detection systems and the active passive fire protection tools? Well, so the answer is we could do so many things. I mean not us, they don't want me to do this, but they could do so many things. I'm tended to this becoming a textbook case for teaching fire engineering of all the things that could be done, and most of them are not being acted upon or, when they are acted upon, they act in secrecy, because you know what happens. The industry says we've invested into protecting them, protecting them from what You've been denying that. This was an issue for the last 15 years.

26:53 What are you protecting them from? So the industry has created themselves a situation where now they cannot even say that the assets are safer or that the assets are now being protected, because they've been denying the problem for too long. You know, I believe in explaining what fire engineers can do by explaining the layers of protection. As many layers as possible should be put between the fire and the asset we want to protect, this being life or property and environment, and it is not right, from my point of view, to just put one layer. You have to put multiple, because no layer, no single layer is perfect and the more you put, you drastically decrease the chance of a fire being able to breach through more than one layer. And the most popular layer, the one where I've met more people talking about that, is immediately the suppression industry.

27:42 So now, with blinking eyes, with dollar signs in their eyes, what an opportunity. We are going to put suppression system in every single nacelle, and the industry pushed quite hard into this. They developed a few suppression systems which are specifically for nacelles for wind turbines. They work. I've seen results of this. They work. Some of them are based on gas flooding, Some of them are water mix, some of them are sprinklers. They work. They have two problems. One is they're expensive and the industry doesn't have a problem. They say so therefore, why put money into something that is not a problem? And the second one is they make the nacelle heavier. It's important that the nacelle is light.

28:22 Obviously, you have to store bulky material and water or different agents, and that means that designers some of them, have put suppression systems in the nace cell, but they dislike it tremendously. Boje, I've met designers of leading wind turbine companies and they were looking into my eyes. I was giving them a presentation with my data and they looked into my eyes and they said I don't want this in my wind turbine. And I said why? And they said because we don't need it, because it's too expensive, because it's too big. And I say hey, because we don't need it because it's too expensive, because it's too big. And I thought and when do you come up with a number for safety? When do you come up with a number for I don't know? It has to be a threshold where the number of fires starts to trigger the requirement for technology.

29:06 That was not the conversation, and he was a leading engineer. He well, all of them. There were many of them. The second layer that is popular now is not popular at all, but it's the most popular because no one talks about it, but a little bit. It's evacuation After people die, unfortunately while they were doing maintenance of a nacelle and they could not evacuate and no one could suppress the fire, and this was very dramatic because it happened in the front of everybody. They started to invest into emergency evacuation, which means systems that are in the nacelle or they're carried by the workers such that they can, in case of emergency, evacuate. The most popular one is ropes Ropes that you immediately can attach to different parts of the nacelle and immediately go down requires training, or ladders that you can roll so they don't take much space.

29:54 I mean, remember, the tower inside is hollow and it has a ladder, but if the smoke goes into a tower then you cannot evacuate, or there is one access into the nacelle and you cannot access it, so to roll ladders that are made of rope, for example, and obviously there's people who thought why don't you just jump from the top of the nacelle with a parachute? But that's extremely dangerous. So that has not been pursued and they have even thought of what about a helicopter trying to go and rescue them. But also was considered to be way too dangerous. Next to spinning burning blades of a wind turbine. Extremely dangerous. But believe me that people thought about it. So now there is a little. You know what they did. It was very nice. There was a little paper on this.

30:35 They started to calculate the evacuation time. It's like, you know, for engineers. Yeah, that's what you do you calculate the time it takes to evacuate and you compare this to the time for untenable conditions in the exit route, and then you make sure that these are rays and that your people are faster than the fire and the smoke. That's no, that's fire engineering. Well, it took them a long time to start doing this. Good direction. Come on, be positive. What about detection? Detection is a mystery to me because the wind turbines are full of sensors. It is a science craft Boje. It has so many sensors. Sometimes not even the experts know the sensors they have. They measure everything.

31:16 Literally name a sensor, they have it. None of them is being used for fire safety. That is one of the biggest mysteries I have with the people in the wind turbine industry. It's like you could use about 20 of these sensors for detecting fire. Obviously it would not be straightforward. None of these sensors was developed to detect a fire. I understand Some of them are measuring no light conditions inside the nacelle. Some of them are measuring temperature. Some of them are measuring vibrations that could lead to hotspot in the fiction event. Some of them are looking into malfunction of the cables, which would indicate arching. These sensors would require some work to be converted into detection, but the sensor is already there.

31:56 The capital, the investment, the signal, the monitoring, the storage, everything's already done. And what about passive fire protection? Separation and compartmentation? I think it's properly called. Super important I mean compartmentation is you have such a. The Nacelle is such a big place, it's a multi-story room without windows. You might have a fire because an ignition source has found a fuel, but you want is not to avoid the spread of the fire and the smoke the smoke because it might actually get the ignitions into trouble, and the fire itself because it would lead to, instead of repairing the wind turbine, which is something relatively easy you don't want to lose a whole wind turbine and you don't want the wind turbine to produce secondary fires.

32:40 So to avoid that is compartmentation, and you find sharp boundaries between the parts that could get into a fire and you just separate with fire resistance. That is something that engineers do all the time. But there's not that many to separate, to be honest, because it's like, on one hand it's full of machinery, but it's fairly simple because you're going to have the main power generating unit. You won't be able to split into multiple fire components. You're familiar with this Fire engineers were invited. Well, first. Fire engineers are not invited to this design, but when they're invited, they're invited when everything has been set. So, how is the fire engineer going to say, hey, why don't we put a separation here? What you mean? A separation across the shaft of the turbine?

33:22 No, we can't. So obviously, if the industry wants to compartmentalize for fire safety, they need to do this from the beginning, To have this from the beginning in mind, not at the end. Fire engineers, we do amazing things, but we don't do magic. What else do we have left Structural? But I guess the damage would not be due to the tower falling down, that's not the best. Very rarely the tower collapses, so typically the tower stays put, Typically not always. Sometimes it collapses. It collapses, it is a hazard to anything that is around, and also take into account that it collapses and it might still be on fire and even the insides of the tower might be on fire.

34:02 So you multiply the chances of a secondary fire when that happens. But the layer that receives least attention although we've published a paper on this is the prevention layer, which is technical prevention. I'm not saying prevention, don't play with matches. No one plays with matches in a wind turbine. Technical prevention is that the ignition source should not be strong enough to ignite the material that is nearby, which should not be too flammable. When there is an intersection between the power of the ignition source and the flammability of the material, then you have ignition. So you should have power sources that are not as powerful and you separate them from the materials that are flammable, and the materials that are flammable should be at least less flammable, not as technical prevention, and you immediately guess what decrease the frequency of fires and your super layer, the fire brigade.

34:50 I guess that slice of the cheese is not on this board. The fire brigades very rarely suppresses tool-bind fires because lack of resources I mean not resources, lack of remit, right, who has the fire brigade, which is mostly paid by taxpayer or the voluntary service, to go up there, to this strange machine that is up there? So I think the only thing we see in our data, the only thing we see is about 10%. So 90% of the fires are left. They burn, and what they do always and they're really good at this is they secure the perimeter. Okay, they avoid secondary fires, or they try to avoid secondary fires, if they can Yet remember, 10% of the fires actually lead to secondary fires, even sometimes with the presence of the fire brigade, because it's a fire that might be burning there for many hours.

35:38 Okay, we got all that is in there, all that can lead to a fire. We've just went through what you can do. And now the reason why I wanted this episode. I mean it's super funny. It's like fire engineering in a probe on a very isolated microorganism that you can totally play with. I wonder there must be a point at which investing in your fire safety starts to pay out. If you have a number on how many of those turbines burn down one per 2,000, one per 10,000, if you know how much a turbine costs, and I would guess that you can scale the cost of the turbine per megawatt of power generation, and the same way you can scale up the production rate of a facility.

36:25 So one megawatt turbine will create like a thousand more than a one kilowatt turbine, right? I wonder if there is a cutoff at which some of those points become a net gain for the investor. Like when do you start making money on fire protection on those turbines? When you will, over the life of your farm, earn more on your sprinklers than spend on putting them in place, right? So this is a very interesting conversation. In our first paper, we tried to have this conversation with numbers, but it didn't lead to a discussion with the industry. No one was interested in these numbers, probably because our numbers were wrong. No, we tried to look into cost of technology versus saving the investment.

37:08 So I'm fine that they didn't like our numbers, absolutely fine. I just thought they were going to have a conversation. The conversation is not happening and I thought it is not happening because for them and they own the data this is not a clear case. For them, it's not clear that fire engineering is needed. I think they feel they can absorb the losses, but I'm going to put two words into this. They thought they could absorb the losses until they realized that they could be having to pay for all the damage they produce around them and many wind turbine farms. There was our own land and surrounded by forests. Some of these forests are very large, some of them are very pretty, some of them are very famous, some of them have people inside, and that's when the wind turbine industry started to feel more uncomfortable about this.

37:52 When the wind turbine industry started to feel more uncomfortable about this when they said it's not about the cost of a nacelle. That happens one every 10,000, according to Guillermo, one every 2,000, according to someone else. Now is that we have to pay the liability of what we have started. That is what starts to make them happy to consider fire engineering, not the nacelle, the extra nacelle. What is beyond the nacelle, which you know is considered to be a sustainability argument. When you design something, sustainability is to also look into what is not that something. What is the outside in time and space? If someone is doing a wind turbine nacelle and is worried that it might burn the forest nearby, that is sustainability.

38:37 They want the nacelle operation, life to be sustainable. So that's a call for fire engineers to help sustainable energy sources. And the second comment that I wanted to make on this, when we published our paper in 2014, I was recently arrived to Imperial, so Imperial College is here in London. London has more journalists per square meter than any other city in the world, so they were really interested in this paper. We got this paper cover in seven major and international newspapers. It was in Financial Times, it was in the Guardian, it was in. I mean, it was really busy that week talking to journalists all around the world.

39:20 What I discovered is the media immediately, immediately, even before reading the paper, split in two. There was no intermediate. They either love the paper because they didn't like wind turbines and they were covering it because they love it, or they dislike the paper immediately, even before reading it, because it was destroying or it was damaging the wind turbine environment. And then suddenly the same paper was used in two different camps the one that loved it and the one that hated it. The one that loved it is because they were against wind turbines and the one that hated it was because they love wind turbines and me in the middle, and they got me into serious trouble with, actually Imperial College, because the journalists, when they're very intense on these things and they wanted to find holes in our research, sometimes they don't stop because they're being paid for this.

40:12 Pretty sure at some point I've asked Ricky to cover wind turbines and he said he's not going through that again, that week was hell. Okay, that week was hell. And then I thought, you know, obviously I went through the week and then I thought, well, you know, if we steal the pods, it will be for the good. And now we are here, 10 years later. The pod did not move, there was no steering. And then I thought, okay, this is now unfair, because the industry pushed so hard, shielded by some of the journalists, they pushed so hard and they did not delivering to the hopes that we had that they were going to be releasing the data, that they themselves were going to lead this problem. I would still consider a simplified version, without even taking the surroundings.

40:57 It's a really clever exercise to showcase, like you said, the textbook example of calculating the value of fire safety and I think it could become a very nice staple fire safety engineering course example for students to actually calculate the point at which it makes sense. Yeah, I know it's true, and especially because the turbine is growing in size. But maybe your suppression can stay local to one specific. For example, when they're doing that drive, which means they're removing the gearboxes. You remove the gearboxes, you remove one ignition source, which is the mechanical hot splint and a ton of oil. It means that now if you put suppression, you can put suppression in the electrical generator so you can actually have a local suppression that is not just taking care of the whole nacelle, but you're reducing the cost of suppression, and as the wind turbine grows in size, it grows in money.

41:52 You want to protect an asset that is more valuable. I agree with you. There's going to be a point where now it's worth to protect it, even with low frequency fires, and there is even now standards on how to test for suppression systems inside nacelles. This is why I tell you that it's the most popular of the suppression of the protection layers, because the one that was jumped into the first. But it's not the one that I'm fascinated by progress either. So it's not that I'm happy about that layer being successful, I'm not even happy about that layer is the most developed. OK, we've covered it. Let's step for the end of the interview. Let's step a step back. It's also an illustration of battling against new solutions and sustainability, introducing new technologies without taking fire safety into consideration.

42:43 Safety into consideration, do you think? I mean technologies that are meant to relieve the carbon costs or create green energy whatever green means are popping every now and then. What can we learn from the wind turbine industry, example? As fire engineers, unfortunately, because there is secrecy, we cannot learn much. What we can learn is what not to do, which is, when you have a hazard, don't hide it. If it's true that it's not a hazard, if it's true that it's not a risk because the probability is low, make sure that you show everybody, not just your clients, that that's the case, because what we have in this field, in this topic, we have not many lessons to learn.

43:29 We have lessons to avoid. I would love to tell you that the industry got into this. They had committees and the committees decided that the best thing was to reduce the amount of material X and displace material Y and introduce a detection Z until no, I cannot tell you that. What I can tell you is there was an incredible amount of denial, many meetings that I had to travel to, some of these coming back thinking why did I waste literally two days of my life for this? And then I monitor the literature and the literature. There is no breakthrough in the technical literature. Every single time that someone repeats the work that we did in 2014, they keep seeing very similar percentage, very similar.

44:13 The sources are the same, literally, they still rely on the same sources that we rely on 2014. I mean, it is time for having new sources of data. This will be one of the first Fire Science Show episodes when I can just list the entire literature on the topic in the show notes. It's like two papers from you and one from. Elalia Plana's team and with Faye. Yeah, they did the suppression one. I see a CFD one from them. Yeah, so not many lessons to learn, but do you see similar challenges growing within other branches of sustainability in which the fire safety engineers are not a part of the discussion, and perhaps they should?

45:02 Yeah, of course I mean in engineering. It is not unusual that there is a new technology, innovation, we love it and then we discover later on it's always later on we discover that this new technology, this innovation, also brings a new hazard. And obviously it's very important for engineers to understand what is this new hazard, because then it needs to be addressed or removed. If we do not understand the hazard, by definition it cannot be addressed, at least not meaningfully, and it cannot be removed, at least meaningfully. So every new hazard requires thinking and we in fire engineering we see this happening left and right and we are always behind Lithium-ion batteries, facades, you work on green walls, solar power, wind turbines.

45:46 Today, every single innovation, unfortunately, in the 21st century, typically comes with a new hazard related to fire. Some of them have low intensity, low risk, low consequences, low frequency. We can discuss this. Some of them not. Some of them happen often. Some of them are high consequences. Some of them are very different to address, lithium-ion batteries being the most difficult to address because it is not even the chemistry, the traditional chemistry of hydrocarbon fires, and this is what we keep our profession, you know always standing, always paying attention and, unfortunately, always catching up. And do you have any ideas how to put fire engineers in front of that inside the problem, instead of having an industry that isolates itself from the fire science?

46:34 I mean, I'm personally offended because it seems like fire science is a hazard to them, whereas we're supposed to help them right. This is a case literally where you see that in print we're talking about turbines, maybe catching fires, and if you read the paper we're actually saying one in 10,000 is not a hazard. We even said that, especially if you compare it to, for example, the oil industry, which has a fire literally every 10 minutes. We were saying you have one every 12 weeks. Right, this is not a hazard compared to your competitors. Still, people thought far. Scientists are bringing trouble to my community, to my industry. And instead of saying talk to them, embrace them, resolve the problem.

47:15 No, instead of that, they say send the journalists and bark at them so they become quiet. So they saw us as troublemakers, as opposed to wanting them to help, instead of no good hackers that want to help them. They thought we were the bad hackers that were there to cause harm. I see the very same case with electric vehicles and with human batteries in general and many, many of the sustainability technologies. I think that's one of the challenges of the modern fire safety engineering to actually be there, like you know, be present at the table, hopefully from the beginning, from the earliest phases, where you can actually influence the decisions and not just appear after a fire has happened to help me out with the thousands of the same objects I've just built.

48:01 You know it could happen again. Indeed and awareness Boce. It requires awareness. That's what it requires Awareness by engineers, awareness by authorities, awareness by citizens. You know, and you know this very well and your audience probably will know this, but it's always worth remembering when fire engineering succeeds and it has a beautiful successful story over the last hundred years no one knows we exist. I always say I'm Guillermo Rem, I'm a member of a secret society. The audience is not meant to know that we exist, because when they learn that we exist, it's because fires are happening and we are not doing our job. We do our job. Fires appear. Society thinks we are a secret membership.

48:44 And on that secret accent, let's finish the wind discussion. I hope I don't get buried by lawyers and journalists after this. I just send them out to you. You have a very good press team at Imperial. I've had enough of them. Let's see if we wake them up after 10 years. Thank you very much, guillermo, for coming to the Fire Science Show, and let's hope the next one is sooner than the 100 episodes from now. Yeah, no, but yeah, it's true. I look forward and we'll think of more topics and let's see if I can convince you of another one. And that's it. Winterbends on Fire, a microcosm of fire science and engineering. I truly stand by saying it's something we could make a stable, risk-based design example for teaching how to do fire safety engineering, something in which you can put a really good number on the value of fire safety, as sharp and clear as in not many other applications out there.

49:44 I really enjoy this and I think it could be a very nice exercise for anyone to do. Actually Try to calculate at which size of wind turbine, at which energy generation, you'll start to get money back out of putting fire safety solutions inside and when they do not make sense, when they are just a simple cost. It's a really interesting approach. Of course, there's complications to to that, as what Guillermo said, when the wind turbine fires start to create damage outside for which you are liable, for that's a different story. But in this very simplistic way, I think it's a nice way to teach fire safety. So that's it for the wind turbine episode. Of course there was much more into the episode on how the devices burn, how they act in fires, what can we do to prevent that and how can we respond to those.

50:33 But I won't repeat myself. It's episode 150, so instead, let me give a round of thank yous around the table. First, thanks to Guillermo for being the first guest in the podcast, being the guest in episode 50, now being the guest in episode 50, now being the guest in episode 150 and some more episodes as well. So big thanks to you, guillermo, for supporting the mission of the Fire Science Show. Second, big shout out goes to OFR Consultants. We're together for more than 70 episodes already and this is a beautiful collaboration. They are supportive to my mission. They truly believe in what I'm doing in here and help me deliver great content to you every week. And finally, big thanks to you and the listener. I do it all for you.

51:14 I craft new episodes thinking about what you would like to hear, I respond to what you tell me and I try to get guests who will be the most interesting for you. So if you are not listening, there would be no point of me making this show. So I am truly thankful for you being here with me and I really hope to see you here next week. Same place, same time, next Wednesday. See you in the next Fire Science Show episode. Thank you, bye, thank you.