Remote monitoring of ice loading on wind turbine blades based on total internal reflection

The paper presents an optical method for monitoring of transparent icing, which is applicable for remote monitoring of wind turbine blade icing. The method is based on the effect of total internal reflection of light. A point light source is formed on a wind turbine blade. When icing appears on the blade, a light circle is formed around the light source at the ice-air interface as a result of refraction and reflection of light beams; the observed size of the beam depends on the icing thickness. Using several light sources, the method enables field monitoring of icing on the wind turbine blades.