Remote inspection: Digital and location-independent manufacturing evaluation of wind turbines

During the manufacturing evaluation, TÜV NORD inspects the manufacturing process and the produced components of a wind turbine, such as rotor blades, gearboxes or the tubular steel towers. The manufacturer can thus prove that he is able to deliver the required quality and perform series production. This quality verification must be renewed every five years by on-site inspections. Due to the coronavirus-related contact and travel restrictions, on-site inspections are hardly possible at the moment. "We had been working on remote solutions for some time and just now, when the service was urgently needed, we were able to quickly offer location-independent inspections", says Silvio Konrad, TÜV NORD Managing Director and responsible for the Energy segment.

How manufacturing evaluation works as a remote service

Manufacturing evaluation consists of a documentation review and an inspection of the manufacturing process. The first stage of the remote inspection, in which the TÜV NORD wind energy experts discuss the procedure with the customer and review documents, takes place via conference software. For the subsequent stage, the inspection of the manufacturing site, the experts use an inspection tool. "The software adapts better to the existing bandwidth than conference tools and thus ensures greater transmission stability," explains Michael Lange, Project Manager Remote Inspection in the Renewable Energy Segment at TÜV NORD. 

While the expert is sitting in front of a screen, employees of the manufacturer or local TÜV NORD experts guide through the manufacturing hall - equipped with a smartphone, power bank and headset. The inspector gives concrete instructions on where to go and what to see. TÜV NORD recommends a system check in advance to ensure that the inspection can be performed without technical difficulties. Of course, the video transmission is not recorded and the resulting image material is only used for documentation purposes with the customer's consent.

New type of inspection in line with existing regulations

Manufacturing evaluation is part of all current certification guidelines for the qualification of wind turbines. TÜV NORD uses the possibilities of remote inspection based on the existing regulations of the International Electrotechnical Commission Renewable Energy (IECRE), the International Accreditation Forum (IAF), and the German Accreditation Body (DAkkS). Depending on the component type, remote inspections are performed additionally to on-site inspections. In advance, TÜV NORD experts check the compliance with the regulations, carry out a risk analysis and adapt processes and procedural instructions.

Leading through remote applications

Over the past few months, the TÜV NORD wind energy team has successfully performed several remote inspections as part of the manufacturing evaluation with manufacturers from Europe or Asia. "The main advantages are flexibility in terms of time, cost savings due to less travel, the streamlining of organisational efforts and - currently very important - the reduction of direct contacts", explains Lange.

Providing services digitally and thus independent of location is a well-known territory for TÜV NORD. The experts have been working with remote audits since 2019 and were able to quickly expand the service at the beginning of the coronavirus pandemic. In this way, the auditors support companies in maintaining certifications - often a prerequisite for the continuation of business activities. In addition, TÜV NORD experts are already testing visual inspections of wind turbines via drones. During the first flights, the focus was on inspecting the tower for cracks. Inspections via drones can replace the use of rope hoist technology, which means a significantly longer standstill of the turbine, at least for an initial assessment.