Abstract
Demand for wind energy, one of the most important renewable energy sources, will continue to expand, considering the outcome of the last COP28. A critical impediment in the use of wind turbines to harvest wind energy is its unpredictable reliability. Turbine blades are a vital and expensive part of a wind turbine. Over its service life, they can undergo degradation through exposure to environmental elements and fatigue, which can limit their effectiveness and safety. There are many failure modes that affect the performance of wind turbine systems. In particular, surface, and sub-surface damage (e.g., cracks, delamination) of the materials of construction for examples, fiberglass or carbon fiber composites often used to manufacture rotor blades are common.
It is also extremely difficult and hazardous to conduct periodic inspection, maintenance using human workforce in the offshore environment. Inspection requires personnel to be transported to the wind turbine, transferred to a rotating structure. In addition, frequently changing offshore climate with high winds in deepwater, all the while working at heights and in confined spaces, make this activity risky. Development of more evolved designs and the application of reliable and cost-effective turbine condition- monitoring techniques will help resolve this constraint.
Reducing operation and maintenance costs of wind turbine blades and other key rotating components is of paramount importance for success and global adoption. Thus, the ability to detect damage of the blades is of great significance for planning maintenance and continued operation of the wind turbine.
The current state of the art in inspection of offshore wind turbines involves personnel using drones to perform visual inspection both internally and externally. The use of drones, a great step forward, cannot however avoid having personnel on location. Further, working at heights is not something that can currently be avoided. Internal inspection of the turbine structures and working in confined spaces are also still required. The next evolution in the state of the art in inspection is to remove or significantly reduce the need for human intervention. This evolution requires several technological innovations, which include new intelligent materials that can act as sensors, enabling remote monitoring of damage to the turbine structure, both internal and external, due to stress, fatigue, environmental corrosion among other deleterious force-fields.
Strategic use of nanoparticle sensors with unique photonic or acoustic fingerprints, embedded in the engineered to order nanocomposite bulk has demonstrated to impart a degree of intelligence, permitting remote monitoring of cracks, fatigue or environmentally induced, as they are developed during operation, identifiable during periodic remote inspection. Test coupons made of a laminated nanocomposite with smart sensors layered in its bulk, are being developed, and tested to establish the concept. Salient results from testing of the composite will be provided at the end of this project, establishing pathway to scaling up and commercialization. The key impact of extending this technology to the offshore wind industry will be to enable a step-change in maintenance safety by enabling the potential to perform human-less inspection of components such as turbine rotor blades.
