Drones in routine use: the future of power grid maintenance

Severe weather and lightning strikes are the main cause of damage to power lines, followed by misguided bullets fired by amateur shooting enthusiasts. It is therefore important that network operators carry out regular checks on the condition of their cables and masts. The best way to do this is from the air. That's why you will often see linesmen working on overhead power lines up at a height of 70 metres, suspended from the side door of a helicopter. Or climbing up to this height on an overhead power line mast.

When it comes to repairs, the expertise of these professionals – as well as their resistance to vertigo – is vital. But for inspection, there are alternatives – even now, drones are being used in trial runs to help to detect melted insulators or damage caused by external factors.

EU regulation enables the routine use of drones

Efficiency and workplace safety are the main arguments here – after all, this concerns a huge number of power lines. In Germany alone, a country with a relatively small geographical area, the power lines that form the most important networks total 641,000 kilometres in length. This is almost the equivalent of a round trip to the moon – and this is increasing, as the growth of renewable energies demands more robust power grids.

A further point to mention here is that, as of the beginning of the year, the flying of drones is now permitted for simple, routine applications across the whole of the EU. Using a standardised Specific Operational Risk Assessment (SORA), it will now be possible to carry out specific "missions" at various different locations with the same standard processes and operating procedures. The inspection of power lines can then in theory be carried out according to the same principles across the whole of Europe.

For such tasks, operators can use easy-to-handle quadrocopters or so-called VTOL drones (for vertical take-off and landing), which also have aeroplane wings that allow them to cover longer distances. In terms of figures, up to 100 kilometres of power line can be inspected in one trip, starting from the boot of a car.

Automating maintenance: "Digital Twin" of the power network

The pictures taken by drones can provide helpful indications on malfunctions in the mast or the cable. If they are equipped with enhanced sensor technology, such as laser scanners or corona cameras, a whole host of further defects can be identified, for example, damaged insulators or bent masts.

However, these “flying assistants” are only the first step on the road to more efficient maintenance of the overall power grid. The data they collect could in future be evaluated by an automated process and combined with data from other sources – such as the photos taken by technicians and also high-resolution satellite pictures.

The vision: An integrated grid management system as the digital twin of the real-world power grid – comparable with systems already in place in the wind energy sector. It should be possible to automate both the export of a drone flight route from the asset management system and the activation of work tasks – for example, where a defect is suspected. umlaut is already working on these concepts – so that a helicopter will only need to be used when it is absolutely essential.