Jessica Schulz | 03/04/2021
Common damages and how you can avoid them
The complexity of wind turbines increased due to ever higher efficiency and performance. This also raise up the risk of damage to the turbines. These range from gearbox damage to electrical damage to lightning or even fire damage. These can result in downtime for the operator and high costs for the insurance companies – which may be avoidable.
In the meantime, design and calculation methods as well as optimized manufacturing processes are in use, which reduce the risk. Nevertheless, damage to wind turbines can and will occur again and again. Operational monitoring systems, CMS (Condition Monitoring Systems) remote monitoring systems and regular maintenance/inspections are most likely to protect against damage. Early detection is the keyword here.
Occurring damages on wind turbines
The gearboxes of wind turbines are exposed to special loads such as high forces caused by gusts of wind, turbulence or tower vibrations. Therefore, premature material fatigue as well as material separation and chipping can occur.
The high number of load cycles can cause damage to the rotor. These are among the most expensive. Small errors during design and manufacturing or mechanical damage caused by abrasion can lead to extensive damage over time. Icing, for example, can lead to an imbalance in the rotor, but can also cause damage to other parts of the system.
Due to their height, wind turbines are an easy and frequent target for lightning strikes. On average, each turbine is affected once a year. A lightning strike can cause damage to the rotor blades (spalling, cracks, buckling), the sensor system or the electronic switchgear.
Fire damage can be caused by overvoltage or defects in the electronics. The most common cause of fires is lightning strikes. Fire causes enormous damage to the entire system and almost always results in a total loss. Extinguishing a fire is almost impossible due to the enormous height of the wind turbines.
Electrical damage can occur to the substation, cables or, for example, the semiconductor components. These can be caused by fires, overvoltage or similar.
Damage to the tower
The supporting structures of a wind turbine can also suffer damage for a variety of reasons. Depending on the type of tower, this can include cracks or spalling.
The list of damages can certainly be continued, but the ones listed above are to be emphasized, because they usually cause the highest costs. But with optimal prevention, damage can be avoided.
Avoidance of damage – damage prevention
Damage to wind turbines cannot be completely avoided, but there are nevertheless some ways to at least minimize the risks.
On the one hand, an operational monitoring system as well as a remote monitoring system should be used in order to be informed about the current status at any time. Secondly, regular maintenance and inspections should be carried out, even beyond the legal requirements. If damages, e.g. small cracks or a defect in the lightning protection system, are detected at an early stage, they can be repaired in time and serious consequences and high costs can be avoided. These interventions cost time and money, but both are well invested. In addition, there are innovative methods in the area of maintenance and inspection, such as drone-based inspections or contactless lightning protection measurement.