May 26, 2020 STRUCTURAL HEALTH MONITORING, WIND TURBINE, WHITEPAPERS
Can you detect a 15 cm crack in a wind turbine blade without stopping the wind turbine? A three-year-long research project, partly financed by the Danish government, proved that this is indeed possible.
Modern wind turbine blades are designed to last for 20 to 25 years under severe weather conditions, and during this period, damage is unavoidable. Almost inevitably, a small blade defect will develop into a bigger failure, which if no countermeasures are taken, will become critical, causing serious consequences.
Repairing a small defect is significantly cheaper than repairing a bigger one or replacing an entire blade. Therefore, wind turbine operators pay close attention to monitoring their fleets’ blades. Today, this is done by periodical visual inspections conducted every one to two years. For such an inspection, the wind turbine has to be stopped, then a service technician, often trained climbers, checks every inch of the blade’s surface and documents any defects found. This is a tedious and risky job that can only be done in good weather conditions. Since such inspections are quite expensive, many in the industry realize that a better approach is needed.