Overview
Nowadays, Wind Turbines (WT) are one of the most efficient ways to produce green and sustainable energy, contributing in a high percentage to all renewable electricity. However, due to the stress suffered by the blades and caused by wind gusts, there is a continuous need for inspection and maintenance. According to CWIF an average of 3,800 blade failure incidents annually are attributed to poor maintenance, with a cost varying between 90,000€ and 900,000€ each, involving many of the accidents human injury and fatalities. Blades reparations can be costly in downtime and expensive, and at the same time this fact reduces turbine’s operational efficiency. For these reasons, preventive planning through more frequent inspections is a necessity.
To achieve a thorough investigation for defect presence on a wind turbine blade, close inspection is required. Current inspections carried out in wind turbine blades, like visual examination or Non - Destructive Testing (NDT) inspections such as thermography, acoustic emission or ultrasound, require skilled personnel or “workshop environment”. This implies either trained staff tied with ropes on the blade or dismantling and transferring the blade in a workshop environment. While blade dismantling is scarcely used because it requires very long downtime, human inspection also involves a relatively high delay.