Show notes
Pete Andrews from EchoBolt discusses their advanced ultrasonic technology for inspecting and maintaining wind turbine bolts, which can reduce maintenance costs by up to 90%. He emphasizes the importance of proper bolt tensioning during installation and highlights recent improvements in their automated inspection processes.
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Allen Hall: With wind turbines growing larger and critical bolted connections under strain, the wind industry needs smarter inspection methods to prevent costly failures. This week we speak with Pete Andrews, managing director at EchoBolt. EchoBolt has developed ultrasonic technology that makes bolt inspections faster, more reliable, and saves wind farm operators up to 90% on maintenance costs while preventing catastrophic failures. Stay tuned.
Welcome to Uptime Spotlight, shining Light on Wind. Energy's brightest innovators. This is the Progress Powering tomorrow.
Pete, welcome back to the show.
Pete Andrews: Hi, Allen. Hi Joel. Good to be back. I was trying to work out when I was last on here, but it was it two years ago. It's been a while. Anyway, we've had a lot change at alt yeah, it's good to catch up with you guys again.
Allen Hall: It's been too long and so we're glad to have you back because I know there's been a lot of improvements and EchoBolt has been really busy checking bolts all over the place and we've, Joel and I have been traveling around quite a bit and we've noticed problems with.
Bolts in the United States and we think where's Pete? Where's Ebol? We could really use you in the United States to help us on some of these bolted connections because it does seem like there's a lot of issues from tower bolts to blade bolts to bolts in general, there are a number of problems that exist.
And I wanna start off there, Pete, because I think you're the knowledge base for bolts. Are bolts being tightened correctly based upon all the measurements that you have done?
Pete Andrews: Say, it's a very mixed picture. I think you're right to point out, it's every wind operator will have issues in their fleets with the bolt of connections, but it's almost always.
Blade studs that caused the most headache. You do see things on towers. You do see a kind of occasional issues elsewhere, maybe with foundations. I'd say it's probably, I. In our experience, once, once sites are in operation, there's not too much that happens that influences the integrity. An awful lot happens at the point of installation, and it's what we always try and say to customers if it.
If you confirm that the bolts are tightened to the load, you expect at the point of installation, you've set yourself up for a fantastic operational li life. But if it's wrong at the start, you've got embedded integrity issues that are really hard to manage going forward. So yeah it's a mixed picture, but what I'd always say is focus on the QA at the point of installation and things should go easy from there on in.
Allen Hall: It does seem like blade bolts are becoming more of an issue. As you mentioned, the blade insert question of are we over tightening fasteners that go into the blades and pulling out these inserts and causing some of the problems downstream root cracking, instruments becoming loose, blades becoming loose and wobbling on the pitch bearings.
It does seem like we don't have a really good way of consistently tightening or tensioning. Those fasteners are bolts that are in composite structure just a lot more sensitive to or the composites more sensitive to the tensioning tightening that happens? I
Pete Andrews: think without doubt it's a harder joint to design and I think probably all of the major turbine OEMs.
It's the area, I guess probably with the most dynamic loading or the most variable dynamic loading and probably the hardest to anticipate the performance of the joint. I guess we see a couple of things. We see a. Occasionally you do get overt tightening, particularly on torqued joints. Most blade studs tend to be tensioned, where you stretch the bolt rather than turn the nut or the bolthead.
But where it's torked, you have a very wide degree of variability and there can be, there can be issues with going back and retalking and trying to measure an angle of turn and over overstretching the bolt and failing them. So we've seen that. I think on the tensioned joints, typically you get very good variability and the bolts tend to be within a narrow band, but probably not enough is being done to ensure that you've got as much preload safely within the bolt as you can.
And I think. The one meaningful action operators can take without having to redesign the joint or try and redesign the fastener, is just to measure the preload and see how much operational headroom you've got and maybe look at increasing it slightly. That's probably the one area. If you're suffering a lot of TED failures, you can address quickly and cheaply without getting into.
Design fundamentals.
Joel Saxum: Pete this week we were at the Blades USA conference here in Texas and we had many side, everybody's talking blades, right? So what blade issue do you have? What blade issue do you have? And one of them that Allen and I had a couple conversations on with operators, there was, oh, we have the root bushing pullout issue.
And some people were very familiar with the issue and, but some people just weren't. They were like, what do you mean by that? I was like, these things are actually loosening in the, breaking bonds and pulling through and all kinds of stuff. So in a blade root, you have upwards of a hundred studs or a, or a hundred of those blade bushings.
How many of them have to start to become loose before it starts to be like a cascading effect? For that blade,
Pete Andrews: the failing of the fixing within the composite structure is not really something we've encountered or looked into a lot. I think typically most manufacturers would place a limit on how many alts failed be before you need to stop the turbine.
Some of them have overall limits about the number in the joint and some have adjacent limits. I think it's pretty normal for people to run with one or two failures and the structured still be still be safe to operate. But I think where you start getting consecutive failures, you have to look quite hard about.
The decision to continue to operate the unit, but particularly since the failures often in segments. So there is typically leading and trailing edge segments where you'll see higher risk of failure. So as soon as you've got a couple of bolts in that area that aren't doing what they want or what they're supposed to be, then yeah, I think it's a much harder decision to carry on.
Carry on operating without replacing those fasteners.
Allen Hall: Are there OEMs that are asking for those blade bolts to be torque still or has everybody moved on to tensioning? I
Pete Andrews: think every modern turbine we work on is tensioned. Some of the, we get quite involved in life extension projects where turbines have got to sort 20, 25 year operating life.
People are trying to make an assessment of, is it safe to continue? Do we need to do wholesale replacement of components, et cetera. And so a lot of the older fleet or some of the older fleet would have talked talk blade studs, but often, we can go in and if we can prove that the bolts are operating in the preload envelope.
The ideal preload envelope, let's say. We can also look for defects, so we can look if the bots have got cracks in them and help the people make that call to just continue to operate safely with a monitoring regime in place rather than perhaps following a recommendation. From an OEM, which might involve wholesale replacement.
Allen Hall: I think that's fascinating, but I asked that question because there's a lot of repowering happening in the United States, and it did seem like turbines that are 10 plus years old. There was a lot of torquing of blade bolts, and now that we're going to repower, one of the questions is, do I need to go back and look at that blade root area and do I need to address it because I overt, tightened, and or retort over the years and damaged that root section.
Is that something that EchoBolt and its technology can actually check? Because I think that's one of the variables that we don't know right now is this bolted connection okay. To live another 10 or 15 years. Is that something that the technology at EchoBolt can derive? We can
Pete Andrews: definitely to derive the bulk loads so we can have a look if.
If the bolt is over or under tightened, what we don't do is the structural non-destructive testing. So we couldn't look at the blade root bolt fixing structure and make any comments about the integrity of that. But we can look with you or with operators. What's the tension or tithing process they've followed?
Does it generate the preloads that you would expect? Is there a risk of overti or in the tighten box? So that's really our specialism.
Joel Saxum: What you guys do is very valuable at different life's stages of a turbine, right? 'cause what earlier we talked about hey, right at commissioning you should be doing, you should be checking all these bolt connections or tension connections.
Either way. And then we talked a little bit we jumped forward, talked a little bit about lifetime extension during the repower phase. But another critical phase of life, specifically in the States that we deal with all the time is end of warranty.