Autonomous drone inspects operating Rødsand 2 turbines using cameras and thermal imaging
An autonomous drone at Rødsand 2, situated to the south of the Danish island of Lolland, was hovering around a spinning offshore wind turbine and capturing images of its blades.
However, the turbine didn’t halt for its inspection. This is the strange thing about it.
A blade inspection usually involves bringing the turbine to a stop so that the inspection can be carried out on its surface.
While the AQUADA-GO system includes both visual imaging and thermography, RWE’s description of the Rødsand demonstration clearly refers to the visual camera footage.
But the AQUADA-GO project aims to eliminate this step from the process.
The blades keep moving
Rødsand 2 has been operating in the Baltic Sea since 2010.
Its 90 turbines are rated at 2.3 MW each, giving the wind farm 207 MW of installed capacity across 34 square kilometers of sea about nine kilometers southeast of Rødbyhavn.
Every rotor spans about 305 feet. Traditionally, inspecting something that size means taking it out of production first.
AQUADA-GO instead combines automated flight planning, cameras, computer vision, and thermal imaging so a drone can examine blades without touching them while they continue rotating. The electricity keeps flowing.
A crack can leave a thermal trace
A regular camera can be used to detect surface-level damage.
Thermography probes further inside.
As DTU researchers note, when the damaged material of the blade undergoes mechanical stress, some temperature differences may occur due to friction and be detected by thermal cameras.
This information is another image for computer analysis.
Using computer vision and deep learning algorithms, it is necessary to find some patterns in the data coming from cameras that can be interpreted as some defects.
Hence, the system is not only taking pictures from the air but also trying to process them to detect defects in real time.
Rødsand 2 was the offshore test
This technology had already undergone numerous demonstrations on land before the Rødsand demonstration.
The partners, which included DTU, RWE, Statkraft, TotalEnergies, Quali Drone, and Energy Cluster Denmark, had leveraged these earlier demonstrations to collect visual images and optimize the artificial intelligence system.
The Rødsand 2 demonstration was the next step to take this idea offshore.
According to RWE, this demonstration was successful at capturing video footage of surface blade damage while the turbine was operational, marking it as the first autonomous drone inspection of operating offshore wind turbines.
However, there is an important caveat here. While the AQUADA-GO system includes both visual imaging and thermography, RWE’s description of the Rødsand demonstration clearly refers to the visual camera footage.
Stopping a turbine has its own cost
Inspection cannot produce power.
When the blades of a turbine have to be inspected, and that involves shutting down the turbine, there is production loss due to the inspection itself, as well as spending money on that activity.
Offshore access complicates things further.
It may involve using boats and good weather just to get to the machine, and dealing with large rotating structures has obvious safety implications.
The goal of the DTU project is therefore not only technical but economical too, reducing blade inspection costs by at least 50% and lowering offshore wind power’s levelized cost of energy by 2% to 3%.
These are the goals of the project and not the savings achieved from Rødsand 2.
The drone is becoming part of maintenance
DTU further adds that the technology has already been employed in over 50 turbines in Germany, Sweden, Denmark, France, and Portugal.
It has been found to detect internal faults that cannot be detected even by the naked eye.
This is such an innovative and accurate method that it is now being considered as the quality control test and certification method for blades in factories.
However, for energy conglomerate RWE, putting this drone technology into use offshore was the practical realization of the theoretical promises. “The Rødsand 2 site is no longer a research project but a well-established wind farm,” states DTU.
In the Baltic Sea, gigantic blades of the turbines need to keep on generating electricity amid harsh conditions of salt spray, driving rain, cyclic loads, and extreme weather.
As this new technology enables the drones to check the massive blades without the need to stop the spinning rotor, there is no need for any downtime, thereby ensuring that an uninterrupted supply of electricity keeps reaching the grid.
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
