What Rosie Learned in Europe’s Wind Turbine Test Labs

Allen Hall (0:00)

Okay, now you're teasing. That's not right. Did you see any new great technology? Or you just felt like it was happening behind these closed doors that you were not allowed behind?

Rosemary Barnes (0:11)

There were some specific things that were being tested, and I'm pretty sure that I'm not supposed to publicize exactly what it was.

Allen Hall (0:18)

You can tell us. We will not tell others.

Rosemary Barnes (0:22)

Everybody listening to the podcast has to promise not to tell anybody.

SPEAKER_3 (0:30)

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 (0:44)

Welcome to The Uptime Wind Energy Podcast. I'm Allen Hall, and I'm here with Rosemary Barnes and Yolanda Padron. Rosemary just came back from her long trip to Germany, and a good bit of it was also spent up in Denmark. Rosemary, you visited a number of wind-related companies on your travels, so give us a little update.

Rosemary Barnes (1:04)

Yeah, I started in Copenhagen and then went over to Roskilde, to Riese, mostly to see their rain erosion test facilities, but I also got a tour of the rest of their testing, mostly blade testing. Also a really interesting history of the region, or of that facility started out as a nuclear power research and had a reactor there. I didn't even realize that. So yeah, interesting history.

Allen Hall (1:35)

Yeah.

Rosemary Barnes (1:35)

And yeah, incidentally, the reason why it turned into wind facilities is because they had all of these amazing wind measurements already for the site, because it's super important for if you've got nuclear power, if there's a meltdown, you need to be able to track where the fallout is going to go.

And so they knew the wind speeds in the region really well because of that. And I'm told, I was told by my friendly guide, that that is the reason why that was seen as a really good place to get started on researching wind energy in Denmark, because they already, yeah, like they could put a turbine up knowing what was going on with the wind resource there.

Allen Hall (2:20)

Niels Bohr worked there, right? Is that the...?

Rosemary Barnes (2:22)

Yeah.

Allen Hall (2:23)

Part of the history?

Rosemary Barnes (2:24)

I don't think he just worked there. I think it was like his facility. I think he set it up. I should have...

Allen Hall (2:29)

His facility?

Rosemary Barnes (2:29)

Yeah, I didn't plan to talk about this. I haven't actually verified any of this. It's just, yeah, remembering what I heard, you know, like Superjet lag two weeks ago and taking it as gospel truth. But yeah, my understanding is that he set it up to do nuclear power research.

Yeah, and then they don't do that anymore. But they do a bunch of energy stuff, but mostly it's wind energy and then a bit of stuff with grid. Some, yeah, they're doing some interesting trials like with EV charging and how that can integrate well in the grid that's powered by variable renewables. So they've got their own little micro grid going on there. And you can, if you participate in the trial, then you can charge your car for free, I think, if you're, yeah, if you're in the trial and otherwise they've got cheap on site charging. Actually, all of the businesses that I visited in Denmark had just rows and rows of EV charges. Mostly not free though. You mostly are having to pay for them.

Allen Hall (3:27)

So you went to the research labs at RISO. The structural labs there, did you walk through where they were doing blade testing and some of the structural testing?

Rosemary Barnes (3:39)

Yeah, yeah. And actually, there's an American guy who's there that took me through, Derek. He was working at NREL in America before that and had worked for TPI for a while. So he took that expertise and brought it to RISO. And they've got a bunch of test rigs in there for small blades, like I think, I can't remember the exact length, but it was only like maybe 20 meters or maybe even shorter. Yeah, so little small ones. I mean, back in the day, that was a full scale wind turbine blade, but now it's small scale. I'm using it mostly for research.

Yeah, trying out various different new things, and they produce blades for other research facilities as well and test them. A little bit of new manufacturing techniques that they're trying out.

Yeah, new testing techniques. One of the interesting ones was, you know, like normally when you test a wind turbine blade, you start out with a static test. So you just like get some ropes basically and pull on the blade sufficiently that you're representing like the largest gust that that blade should ever experience in its lifetime. And yeah, after you've done that test, then you're going to do a fatigue test. So then you just got to flap it up and down and side to side, one after the other. And that takes months and even for like really long blades. It can take like say a year because you can only flap as fast as the natural frequency of the blade. And so yeah, if you get like a longer blade has a slower natural frequency. So it takes takes longer to do the full millions of hundreds of millions of cycles of of bending that it sees in its full lifetime. And they've got new test methods where they're trying to do both flap wise. That's the direction where it's the gust of wind is blowing the blade into the tower. And then edge wise is the direction where like gravity is bending it on each rotation back and forth. So that normally you do test those one after the other. You just, yeah, like put it in one direction, flap it upside up and down for millions of cycles. And then you swap it the other way and flap it up and down for millions of cycles. But now they've got this kind of I don't even know how to describe it, there's some actuators where they will actually set it off so that it's doing, it's like tracing out an ellipse kind of in every flap. And so it's doing both flap-wise and edge-wise at the same time. And so you can get through the test faster. And also, you know, people want combined loading because in reality in the field, you've got both flap-wise and edge-wise and some combination at the same time. And I kind of get the point of that. I don't personally think that it is particularly like it's a new way of testing. And I don't think that it's like just because it is two loads at the same time doesn't mean that it represents like reality of how those two loads co-occur in reality. So I'm not entirely sold on that being a more realistic test, but it is good if they can do these two fatigue tests at the same time and save some months on the testing. So that was interesting. Another thing is that they're looking at ways to test torsional rigidity a bit better, because that's more and more important as blades get longer.