Finally, when higher thermal performance is needed, PC systems could include innovative transparent materials in the structure, like translucent granular aerogels: U-value is equal to 0.9 W/m2K for a 25 mm total thickness panel and it could reach0.5 W/m2 K for a 50 mm thickness; the value is of the same order of magnitude of a triple glazing window with two low-e layers, but Innovative PC systems could be easier applied in commercial buildings (roofs or walls), because of the lightness.