The EU target for the reduction in greenhouse gas emissions is 55% by 2030, an increase from its previous target of 32%. Whilst the global energy demand is projected to increase by 9% by this date. To achieve this new target, an increase of between 40% and 66% renewable energy is required, the majority of which will be wind or solar. To maximise energy output from wind turbines (WT), they must be operated efficiently with their aerodynamic performance maximised and down-time minimised.
Wind turbine blades (WTB) must withstand enormous strains during operation, as they are stressed by an extreme dynamic load spectrum. In addition, they are directly exposed to environmental impacts, such as temperature change, precipitation, and lightning strikes, as well as erosion (e.g. salty and/or sandy environments). This can lead to WTB failure, resulting in damage to the wind turbine tower (WTT) and the other WTBs, or the loss of aerodynamic performance leading to decreased annual energy production. In order to prevent such situations, WTBs must be inspected regularly enabling them to be repaired, or withdrawn from service before failure occurs. Regular inspection and maintenance is associated with several issues:
- Inspections are hazardous: Accidents and fatalities can and do occur. In 2020, there was a total of 532 reported incidents in the wind industry, of which 86% were associated with operational wind farms.
- Maintenance costs: As WTs are becoming larger and are installed at more remote locations, inspection and maintenance activities become more difficult and expensive.
- Operational efficiency: WTs only produce energy when running. Stoppages for inspection and maintenance (planned or unplanned), or repairs reduce their efficiency.
To address the above, the SheaRIOS project has developed a robotically-deployed system for sub surface defect detection in operational in-situ WTBs. The SheaRIOS system combines robotics and shearography to deliver a more efficient and safer inspection method, compared to currently available techniques.
The system is able to identify subsurface defects invisible to other inspection methods. It will improve safety by enabling operators to remain at ground-level, thereby removing the need for working at height during the inspection process.
