In order to protect wind turbine blades against lightning, a new foil has been developed that evenly distributes the energy potential of the lightning current over the entire length of the blade. It does this by catching the current and leading it either to lightning receptors or directly to the tower. The underlying principle is a resin — embedded copper mesh layer applied between a polyurethane or fluorpolymer film and an adhesive.
Likewise, to enhance the performance of a wind turbine and to reduce its running noise, a self-adhesive foil which is designed to mimic sharkskin and applied in parallel to the direction of the air flow reduces the air resistance by about 8%. Since, in order to operate economically, wind turbines normally require a wind speed of about 4 m s-1 at a height of 10 m, this aerodynamic foil allows them to produce electricity at lower wind speeds. ‘Sharkskin foil’, which is made from adhesive-coated polyurethane film provided with a fluorpolymer ‘sharkskin’ microstructure, has been successfully applied to aircraft fuselages to aid airflow since the 1990s.