Nearly all of Senne's vacations are spent as a nature photographer in the most vulnerable parts of nature on Earth: the Arctic region. Here, he not only takes hyper-detailed photos of animals but also captures climate change. For Green Trust, he manages wind and solar parks and also deals daily with images. Not of vulnerable areas, but with sustainable energy projects that, among other things, should help the ice caps melt less rapidly. 

The days here and there look quite different: in Antarctica, he trudges through the snow with a camera bag and lenses weighing ten kilograms, while in Oosterbeek, he ensures that drones fly over solar fields and along windturbine blades from behind his desk. "For a number of years now, the use of drones during inspections of windturbines and solar panels has become more common. In my opinion, drones are a great tool for daily operational management. We receive a load of drone photos, with which we can create reports. Even there, software programs are already being used that make the work even faster," Senne explains. 

Drone photos, so not videos? 
"Indeed, such a drone takes photos of every piece of windturbine blade and from different angles," says Senne. "Photos are taken from the start of a turbine blade to the very tip. Then we process the photos in software programs, which show where sensitive spots are that need further investigation. The images come with comments such as: these are damages of the first category, the second, the third, and so on." 

How often are the inspections carried out? 
"Each energy park certainly gets a comprehensive inspection after two years, this is the end-of-warranty inspection. At windturbines, this is done by people, because that is still just a bit more accurate. Then, of course, there are also inspections to maintain the parks, how often that happens, varies per wind or solar park and depends on the agreements. This is, for example, once every two or three years and can be done with drones." 

Why are drones so popular for inspections? 
"Drones have been on the market for a while, but using them for inspections of wind and solar parks is now becoming more the standard," says Senne. "This is because there are two major advantages to using these flying cameras: it is much faster and it saves money. As an extra, it is also safer than 'Access rope inspections,' which are the inspections where people go along the blades of the windturbines on ropes." 

For solar parks, you don't need ropes to inspect, how do these inspections work? 
"At solar parks, we let a drone fly over the solar park with a thermal camera. This allows us to see hotspots, which show whether the panels are functioning properly or, for example, have burned through. What cannot be seen with the naked eye can be seen with a thermal camera. If necessary, action can be taken. 

 

Senne points at the images that the thermal camera on the drone made

"If you have to walk through a whole field where ten hectares have to be checked and each panel has to be checked with a thermal camera in hand, you'll be busy for a while. This of course used to happen, but I'm glad it can now also be done with drones: much more efficient. And by hand, we could sometimes not even reach the top parts of panels, that was a real puzzle, that's now much easier. With drones, we might be done with scanning the whole park from above in a few hours." 

This sounds a lot faster. Do you now only inspect with drones? 
"For the official takeover of a solar park, the inspection (Scope12) still has to be done by hand. This is when we check the cables and check for short circuits. This cannot yet be done by drones. Also, the inspections with a thermal camera can only be done from about April to September. The wattage for the cameras must be at least 600 Watts and this is usually only in these months. The other months often have too little sun to reach the 600. This can be limiting," Senne tells. 

"For wind parks, if you are really close to a blade as an inspector, you see potential spots better. The advantage of manual inspection is that you can feel the blades. For example, if there is a soft spot or if the paint on a blade is flaking off, you cannot see that on a camera. If you are really on top of it, you do see that and that is an advantage. In addition, inspectors can in some cases immediately carry out repairs when they are hanging on a blade. They bring equipment to repair easy spots. 

Like a band-aid on the blade? 
"No, no," laughs Senne, "this is about small repairs such as gluing a serration or smoothing out small things. A serration is a series of small, serrated edges placed along the edge of the blade, these make for a quieter sound and to increase energy generation. But maybe drones will also be able to do this in five years." 

Speaking of the future, how do you think it will look in five years in terms of drone inspections? 
"I think that solar panels will be inspected by drones even more, I see that happening. It's just much more efficient. Maybe drones will also be able to make repairs in panels or blades at that time. That would be really nice. For windturbines, I only think that you still need to have a thorough inspection by a person once in a while or after the warranty period. As far as I'm concerned, combining drones and human inspections is best. The human inspections remain slightly more accurate for now but who knows, by that time we might have intelligent windturbine blades that can perceive themselves, that would be really cool." 

And what if the drones start doing all the work? 
Senne gets a big smile on his face: "That would be fantastic. Then I have more time to take nature photos and show what we are doing this for."