Weather Guard Lightning Tech

Blade Breaks at He Dreiht, Suzlon Posts Record Quarter

A V236 blade fails during construction at He Dreiht. Plus a 53 GW US wind forecast, Suzlon’s record quarter, and what turbine noise really measures.

Sign up now for Uptime Tech News, our weekly newsletter on all things wind technology. This episode is sponsored by Weather Guard Lightning Tech. Learn more about Weather Guard’s StrikeTape Wind Turbine LPS retrofit. Follow the show on YouTube, Linkedin and visit Weather Guard on the web. And subscribe to Rosemary’s “Engineering with Rosie” YouTube channel here. Have a question we can answer on the show? Email us!

The Uptime Wind Energy podcast, brought to you by StrikeTape. Protecting thousands of wind turbines from lightning damage worldwide. Visit striketape.com. And now your hosts

Allen Hall: Welcome to the “Uptime Wind Energy” podcast. I’m your host, Allen Hall, and I’m here with Matthew Stead, Yolanda Padron, and Rosemary Barnes. And to lead off this week, s- there’s been some trouble in the North Sea. On July 22nd, a blade failed on one of the turbines at EnBW’s 960-megawatt He Dreiht offshore wind farm.

Uh, EnBW spokesperson said there were no injuries, thank goodness, and that the authorities were notified immediately, which is generally the case in Europe. They’re very safety conscious, of course. But the machine was a Vestas V236, which is a– that 15-megawatt offshore turbine that Vestas is offering. And He Dreiht is where the platform [00:01:00] has made its debut.

So Vestas and EnBW are working together on an investigation, an RCA, a- along, uh, looking at the environmental impact because parts of the blade landed in the water. And the, the images I saw online were like a sheer web that was being pulled in onto a ship, so big pieces of blade. Uh, there’s gonna be 64 of these turbines going into that wind farm, but this is probably a little bit of a weird thing because it does seem like that the wind farm is under construction when the blade broke, which is not the first time this has happened, right?

That we’ve seen blade breaks at, uh, Vineyard Wind and at Dogger Bank on the GE side. Is this just a construction issue, Yolanda, you think? Or is it some sort of, uh, vibration that’s happening during construction that’s putting extra stress on the blades?

Yolanda Padron: We were talking about it a little bit offline and how it might be a loading [00:02:00] issue because it’s not, uh, it’s not in the optimal operating, uh, conditions, right?

Uh, but this is– It’s– I don’t like that it’s becoming a trend more than an anomaly from what we’ve seen on this podcast. Uh, Matt, I know you work a lot in solutions, right? What, what would you recommend people start doing?

Matthew Stead: Yeah. I think, um, more and more there’s ways of just checking out, you know, pre-construction, um, you know, some of the vibration modes, some of the unusual, um, wind loading when it’s in standstill, you know, different yaw angles and so forth.

So there, there’s more and more ways of, um, checking out what the blade is doing when it’s in those unusual, um, sort of pre-con, pre-operation phases. So, um, you know, for instance, um, we do know that there is some sort of sometimes edgewise or flatwise vibration, which, um, you know, maybe is not normal, um, and maybe could be, be [00:03:00] thought about in a bit more detail.

Um, certainly I know there are some research organizations which are looking into this and also, you know, things like blade twists. Um, so what is actually happening in terms of the, um, the twisting of the blade along, along its axis.

Allen Hall: I think the last time this happened, I remember going back and looking at patents about how to protect the blades during this construction phase.

So you wanna prevent the blade from generating lift from sideways winds pretty much. So the designs that I saw were like putting like a, a netting across the blade to disrupt the airflow so that it wouldn’t generate lift. But I haven’t really seen that implemented. Maybe it is being implemented, but these loads are a little odd, right?

I, I, I’m wondering if there’s any IEC certification test that looks into them, uh, just because it’s, it’s happened a couple of times now, more than a handful.

Matthew Stead: We, we saw, um, we saw that picture of some blades on the ground. [00:04:00] You remember they were in storage. Um, there was a, a strong wind that came across them when they were in storage, and there was some, some flutter and, you know, some, some damage it caused, uh, even when they were on the ground.

Um, yeah, I think just thinking out loud, you know how on some, you know, wind stacks and, or, you know, turbine stacks and, um, you know, poles, you know, exhaust stacks. Sorry, that’s the word I’m looking for. Exhaust stacks. They have the, the spiral around it. You know, it’s for around vortex shedding. So maybe it’s an opportunity for, for Rosie to jump in here and, uh, and comment.

But, um, maybe we can put like vortex, uh, spiral vortex, um, you know, dissipators on the, on the blades before they’re fully commissioned.

Rosemary Barnes: So it’s cer- certainly not a, a matter of the design just being a little bit wrong, right? That would mean that it would last for a, for a while and then And then break. But it, it also, it could be several things.

It could [00:05:00] have been a manufacturing defect, a bad one. It could have been transport damage. Tho- those are two other things. It could have been, yeah, you know, like a, a new design feature or material that performed massively differently under real loads than what it did, um, you know, in their computer models and in their coupon tests and in their, um, static tests, fatigue tests that they did.

It could be any of those things. Sometimes you do see problems where technically you’re not supposed to leave the rotor locked out for any period of time because it is not designed for the off, off-axis weird loads that you can get when the blade is oriented in a suboptimal way compared to the wind.

And there have been instances where it’s like technically, you know, that was in the instruction manual, however, nobody ever followed it, and it’s only under extreme circumstances where that actually is severe enough to break it. There, there can be instances like that [00:06:00] where I would say that it- it’s pretty difficult/impossible to actually design s- for safety during any conceivable series of events during installation.

The way that you would do it would be to make sure that the blade can handle any wind load and, you know, up to the maximum gust at any, at any time in any position. But having, you know, done a little bit of work, um, on blade design in my past, it is massive. That is just a massive, massive load that is y- it will never see in its lifetime.

You would have such heavy, expensive blades if you actually designed it like that. Um, and so yeah, the That, that would be probably the most charitable reason for a failure where nobody really did their job wrong. It’s just kind of like some bad luck that happens every now and then.

Allen Hall: Well, it does seem like there’s a trend there between Dogger Bank, Vineyard Wind, [00:07:00] some of the things we’ve seen in China.

During the construction phase, those turbines are very vulnerable and the, the blades can break. Aren’t there extra precautions that could be put in place? Like, you...