Lightning Strike Protection for new Composite Wind Blades
As the power output requirements increase for wind turbines, wind generator manufacturers are moving towards larger blades to rotate these larger turbines at lower wind speeds. As the wind blades increase to over 45 meters in length, blade construction is moving away from the more traditional all fiberglass construction to utilize more carbon fiber. The carbon fiber provides a substantial weight savings and increased strength to combat the extreme stress loads exerted on the blades during operation. Carbon fiber, however, is conductive and more prone to be struck by lightning and the carbon fiber is not conductive enough to channel the energy out of the blade. Without proper protection, they are susceptible to severe damage and catastrophic failure in the event of a lightning strike.
For two decades Dexmet has been working with aircraft designers developing precision expanded MicroGrid® foils for lightning strike protection on carbon fiber composite aircraft. Benefiting from the development work done in the aircraft industry, Wind Blade Manufactures are also realizing the importance of having the proper lightning strike protection for larger carbon fiber blades and incorporating Dexmet’s precision expanded MicroGrid® materials into their designs. Dexmet MicroGrid® materials are thin, open area products applied to the top adhesive layer of the composite and are capable of achieving the critical conductivity required to dissipate a destructive lightning strike, protecting the carbon fiber layer below. Dexmet’s expanded copper and aluminum MicroGrid meshes are essential at extending the life of carbon fiber composite blades. In addition to protecting blades, lightning strike materials can also be incorporated into the composite turbine nacelles for additional protection of the structure.