A review of NDT techniques for wind turbines

Historically, wind machines were used for grinding grain in Persia as early as 200 BC. Wind turbines have been in use since 1941 when the world’s first megawatt-size wind turbine was connected to the local electrical distribution system in Vermont, USA. The function of a modern power-generating wind turbine is to generate high quality, network frequency electricity. To give an example of the scale of the industry today, there are over 35,000 wind turbines worldwide and the UK has 40% of Europe’s wind resource. The main aim of this paper is to provide a review of the current state of NDT of wind turbines, based on published evidence, at the time of manufacture and at the time of periodic inspection. Whilst it is well known that Acoustic Emission (AE) is successful in detecting and monitoring flaws in wind turbines, it is not strictly an NDT method. Nevertheless it is considered in this review.