Each of the 48 wind turbines towers above the Cologne Cathedral and the rotor blades encircle the surface area of two football fields – the Nordsee Ost offshore wind farm off Helgoland has impressive dimensions. However, this makes each inspection a logistical challenge. Until now, industrial climbers have taken on this task and abseiled down from the nacelle of the wind turbine at dizzying heights along the rotor blades – a hazard in rough seas and strong winds.
Drones: a safe and cost-effective alternative
innogy is now breaking new ground at the Nordsee Ost offshore wind farm and has used drones to carry out inspections since the start of 2017. The use of drones for visual inspection is not only far less dangerous for the inspectors – they now stand below and control the drones – but also more cost-effective. It can take a long time for a climbing inspector to complete the inspection of all rotor blades, and during this time no energy can be generated. A drone with a high-resolution camera completes this task much faster.
It is currently not clear whether drones will fully replace climbing inspectors. “In the next few days we will examine the footage to assess whether the quality and informative value of the images is sufficient,” says Wolf Kind, Senior Asset Integrity Manager for the Nordsee Ost wind farm at innogy. “Following that we will decide whether we will also use the drone for visual inspection at other sites.”
Modern analyses through predictive maintenance
The Nordsee Ost offshore wind farm, one of the largest wind farm projects off the German coast, generates enough green electricity to supply approximately 320,000 households. Inspection using drones is just one of many process innovations under the principle of predictive maintenance at innogy. Its objective is to proactively maintain machine components using intelligent data analyses. Other projects of innogy such as high-voltage power lines, photovoltaic panels and onshore wind farms have been successfully inspected using drone technology for some time now. Furthermore, use on the high seas could offer further advantages, such as the receipt of particular wind data.