How CNC Onsite Cuts Repair Delays for US Operators

Søren Kellenberger, CEO at CNC Onsite, joins to discuss the company's new US office, uptower yaw ring repairs, and blade root insert replacement. Email [email protected] to learn more. The Uptime Wind Energy Podcast is brought to you by Weather Guard Lightning Tech, creators of the StrikeTape Ultra LPS retrofit. Subscribe to Uptime’s Substack newsletter. And check out Rosemary’s "Engineering with Rosie" Youtube channel. Have a question we can answer on the show? Email us! Episode Transcript Welcome to Uptime Spotlight, shining light on wind energy's brightest innovators. This is the progress powering tomorrow. Allen Hall: Søren, welcome back to the program. Søren Kellenberger: Thank you very much, Allen. It's a pleasure. Allen Hall: Well, you have some really exciting news in the United States, because CNC Onsite has been growing tremendously. You're now worldwide, and you've established a presence in the United States. Søren Kellenberger: That's correct. We have been working in the US for quite some time, but we see that the demand is definitely there. The North American market has more than 100,000 turbines above one megawatt. So of course it's an interesting market, and we think that now is a good time for us to make that move and establish ourselves in the US. So we are really looking forward to that. Allen Hall: So you've seen a lot of growth in the company over the last couple of years as operators worldwide realize they have problems that they can't solve, and that will only be solved by precision machining, which is what CNC Onsite does. Where have you been doing work lately? I've seen things on LinkedIn from Asia, but I know you guys are pretty busy right now. Søren Kellenberger: As you started saying, we are basically working globally. So we have had technicians in Australia and Japan, and in other Asian countries as well. Our main market is still Europe, where we also started, and we are widely spread across Europe. But the US, including Canada, is becoming a very interesting and important market for us. Maybe the best way to explain it is that even though we are based in Denmark and working out of Denmark, 90% of what we do is outside of Denmark. And once you travel — whether you travel to Finland or if you travel to somewhere in the US — it doesn't make a huge difference. Our technicians are away from home and family anyway, so it's just the language that is a bit different. Allen Hall: What brings people to your business? What are they calling about today? I know the yaw ring was the number one item. That's what I remember as being, when you were getting started, the yaw ring with the teeth being broken. Is that still your number one request, or has that changed? Søren Kellenberger: It is definitely often a door opener, because everyone can relate to that. So it brings a lot of interest to the company. And then when we start talking to customers about other wear issues in the turbine, it often turns out that we start to talk about worn sliding surfaces on the yaw ring, or it can be worn out rotor lock holes, or wear and tear to generator shafts or main shafts. There's a whole lot of mechanical things that obviously get worn when you have a turbine running for so many years and hours. And then we just try to see if we can come up with smart ways to fix it uptower instead of deploying cranes and doing large disassemblies. Allen Hall: That's the real problem. I think a lot of operators realize that they have worn assemblies, but they don't really know of any way to address it, so they just live with it, or they try to accommodate as best they can. With the yaw ring teeth, the way I had seen that until I talked to you was they would get a guy with a welder up there and they'd try to weld these teeth back on. But that's really a temporary fix and it's not a long-term answer. You're doing something that is actually better than what the OEM installed to begin with, right? Søren Kellenberger: Yeah. Instead of welding — and I won't say that welding doesn't have its place, because for smaller repairs welding can be a good fix as well. We do also work with welding companies for certain smaller repairs. But imagine you are up in a very confined space, and when you have to start rebuilding a tooth by welding, the more of the tooth that is missing, the more you need. One thing is the welding, but grinding it back to shape again is also a manual process. It's obvious that the more of a tooth that is missing, the more difficult it is to get that actual shape of the tooth afterwards by grinding. So what we do is that we machine away the damaged teeth, and then we bring prefabricated segments that have the actual shape of the original tooth, so that we get very good contact between the yaw gear and the yaw ring after the repair. And I think that is probably the main reason why welding is sometimes not lasting as long as when you have to rebuild a full tooth and then manually grind it. It's very difficult to get that well-defined contact surface. So you get some peak points where you have higher loads, and that will just fatigue those repairs over time, where we have better chances of getting that very good fix. We get very accurate machining because we use CNC-controlled machining, so our repair is within a few hundredths of a millimeter. Allen Hall: Yeah, absolutely. Well, the other approach besides welding and your approach — and this is what I have seen more recently — is the whole nacelle comes off. So the rotor pops off, they lift the nacelle off with a crane, so they have to have a crane on site, and that's really expensive. And they set the nacelle down, and then they have to go in and physically remove the yaw ring, or these sections of it, and replace it. That is extremely expensive and time-consuming compared to what you're describing. What is the delta in cost, roughly? Søren Kellenberger: That is very difficult to say, because it depends how fast you can actually get a crane out. And I guess there is also, in the US, a huge spread on what the deployment cost is for a crane, how close you are to a local crane center, and what the deployment cost is. Then it also depends on your access roads. If the turbine has been out there for 5 or 10 years, maybe your access roads are unfit for the crane anymore. Your hard stand or the crane pad is not in sufficiently good condition to support your crane. So there can be a lot of extra costs that are adding up — not just the rental of the crane, but the overall cost of preparing it and the whole project management of getting that set up. Then you need your support fixtures to place on the nacelle. You need to get your plates down. So it's a lot of logistics, and just preparing the turbine for disassembly is probably about a week. And then you have all the craning and replacing and putting it back together. So if you say you could have everything ready, your turbine is down for, I would guess, two to three weeks. But in reality, the downtime before you can get a crane out there is much, much longer. And we can basically — we have repairs, spare parts, we have them in stock, so we can basically move out the day after we get the call and get your turbine up and running. Installing a segment, which repairs up to six teeth, takes about a day for us to do. Then we need a day to get up in the turbine and get ready, and a day to get back down. So what takes from several weeks to potentially months before you're up and running again, we can do in just about a week. Allen Hall: In the United States, one of the things I hear a lot of times, particularly dealing with cranes, is that procurement, when they want to buy a fix of some sort, doesn't necessarily consider the cost of the crane, the downtime, all those other factors. Obviously, the engineers on the backside are thinking about that, but when it comes to decisions for your technology, that doesn't always get into the mix. Is that a worldwide problem or an American problem? Because that feels like an American problem. Søren Kellenberger: No, it's not. I think it's a worldwide problem. I think what makes the difference is probably that the turbines are typically a bit older in Europe. So in that way, we are a few years ahead in that life cycle. Procurement and also technical organizations have maybe become a bit more used to including that thinking, where this is still a relatively new issue in the US because your fleet is newer. So I think it will change in the coming years, as it will develop naturally as it has done in Europe. But it's also sometimes the structure of the company — that you have a certain organization that takes care of the main component replacement, and then you have a part of the organization that takes care of day-to-day service. And now you don't need to replace your main component, but the work we do is on the main component, so it sort of falls in between those two areas of responsibility in the company. And that can also sometimes be challenging. Allen Hall: So it's not only that you have to get a crane to do a lot of these repairs that you can now do with CNC Onsite, right, internal to the nacelle — but there's also weather, right? I think the one thing we don't consider a lot of times, or have kind of preconceived notions about, is that the weather's, like, 30% downtime. Yes, if you're working with a crane and you're trying to lift heavy objects, there will be 30% downtime because of weather. But when you're doing the repair in the nacelle, what limitations do you have on weather? Is it a much wider window than a crane would have? Søren Kellenberger: Absolutely. We can work up to much higher wind speeds — basically the same wind speeds that you can do ordinary maintenance work within — because our machine is always mounted on the component that we are machining....