Ready for take-off: helicopters to inspect high-voltage lines

Published on 08 April 2022

As the green energy transition gathers pace, the importance of being able to move electricity at a national, and increasingly Europe-wide, scale has never been clearer – and nowhere more so than in Germany. With the country’s coal to be phased out by the 2030s, wind power produced in the North is now needed by industry in the South. This puts the onus on grid operators like 50Hertz to optimise their infrastructure. And that is where SPIE can offer some truly innovative solutions.

In 2020, SPIE concluded a three-year contract with grid operator 50Hertz to inspect its power transmission network with multi-sensor helicopter flights. In 2021, SPIE Deutschland & Zentraleuropa and its subcontractors flew along more than 2,000 km of power lines between Germany’s Baltic coast and the northern tip of Bavaria, mapping them with lasers and using infrared and ultraviolet cameras - as well as the trained eye of an on-board maintenance expert - to detect damage.

Dirk Strauch
Dirk Strauch, head of the service office for special projects

“Grid operators in Germany are now under legal obligation to check whether their networks could carry higher loads,” says Dirk Strauch, head of the service office for special projects at the business unit CeGIT at SPIE Deutschland & Zentraleuropa, “and more electricity means more heat, which in turn makes power cables hang lower,” he explains.

“If cables hang lower,” adds Thorsten Werner, head of business development at the business unit CeGIT, “trees need to be cut back”. And even without changes, trees grow, farmers drive larger harvesters, and new buildings may spring up. This makes inspecting the network and mapping it in high resolution a priority.

1,465 km of 50Hertz power lines were scanned by SPIE in 2020.
Thorsten Werner
Thorsten Werner, head of business development at the business unit CeGIT

A single flyover

“And where other technical service suppliers need to carry out several flights, SPIE can now do the job in just one,” adds Thorsten Werner, explaining that, until recently, laser scanners could only be mounted on helicopters to overfly lines, while thermal imaging cameras shot from the side. So he started thinking about how to combine all sensors in one helicopter.

This puts SPIE one step ahead of competitors, who are still testing similar solutions. “Thanks in no small part to this innovation,” beams Dirk Strauch, “we won a Europe-wide tender in a sector which will see high demand in the coming years.”

Time to take-off!

Thorsten Werner, too, is looking ahead: “Our division already has four operational drones, which we have already deployed in projects for cutting management at 50Hertz. Together with our partners, we are further developing the drones solution, so that we can minimise the use of fuel-guzzling helicopters in the future.” And then there are the terabytes of data the flights generate. In cooperation with Polynome, an artificial intelligence specialist he discovered at a SPIE Innovation Day, algorithms have already been trained to identify power pylon parts with a 95% success rate. Sounds like it’s time for take-off!

More than 95,000 photos had been taken to assess the condition of masts, fittings and connectors.

Three questions put to Stefan Manske,

Operations and maintenance manager at 50Hertz


What challenges are operators of power transmission networks facing?

Germany’s network is solidly engineered and has always offered high levels of stability, but the green energy transition and increases in demand are outpacing new capacity, so we have to push existing infrastructure further. At the same time, regulation – minimum distances, nature protection, etc. – is becoming ever tighter. These combined challenges make optimising maintenance a top priority.

How does SPIE’s innovative approach support 50Hertz in mastering these challenges?

We opted for SPIE after an EU-wide tender because its airborne inspection concept presented both the best business case and higher quality. As well as efficiency and ecological savings from reducing helicopter flights, there are lots of other benefits: previously, we had to fly within 5m of our cables, but SPIE can fly at a distance of 30m, reducing risk without compromising on imaging. We are also generating a huge amount of data about our assets.

Where will the partnership lead in future?

Our path forward is toward a full digital twin of the network which will allow predictive maintenance algorithms and enable us to plan network expansion more easily. I am confident that SPIE is the right partner for us on this journey.

Key figure

5 000

km of 50Hertz’s network, in Hamburg, berlin and across eastern Germany, will have been mapped by the end of 2022.

Key figure


hours of video footage had been recorded.

Key figure


points of attention have been detected and documented on 50Hertz network thanks to helicopter flights.