Development of a Wind Turbine Blade Surface Coating to Reduce Damage due to Lightning

Every year, the global wind industry loses an estimated $100M or more to damage caused by lightning. A new proprietary blade coating will reduce the damage to wind turbine blades caused by lightning by promoting the formation of ionization channels over the surface of the turbine blades. These channels promote surface flashovers, providing a safe external path for lightning energy to connect to the lightning receptors and reach ground, thereby preventing damaging blade punctures, delamination, and catastrophic failures. The coating consists of discrete conductive elements mixed with a topcoat, which will be applied to the blade surface near the tips to enhance the performance of the existing lightning protection system while also protecting the blade from erosion caused by rain or particle impacts and UV radiation. In Phase I, computational simulations were performed to identifyappropriate electrical properties for the coating system. A systematic series of experiments showed that an inexpensive coating system can reduce the flashover voltage by more than 50% on the surface of a turbine blade. This is a requirement for the formation of safe airborne paths for the lightning energy to reach ground and the primary metric of success in Phase I. Successful proofofprinciple experiments at larger scales were performed at a certified lightning test facility. In Phase II, the coating formula was developed and validated in a systematic fourphased program that included smallscale coupon testing and largescale high voltage and highcurrent tests at a certified lightning test facility. The largescale testing was performed on small and large wind turbine blade tips. In the proposed Phase IIB project, two parallel field tests will be performed on existing operational wind farms prone to lightning damage. The field tests will be augmented with additional largescale laboratory testing to refine the product and prepare for product rollout in 2023. Improved wind turbine lightning protection systems will reduce the cost of wind energy by reducing operations and maintenance expenses and minimizing turbine downtime, repair costs, and project risk. These steps will increase wind energy’s competitiveness with and penetration in the domestic and global grid energy markets. The coating can also be applied to new wind turbine blade designs to minimize the risk of lightning damage, increasing design flexibility and the future use of more blademounted technologies.