HELIOVIS AG, a Vienna based start-up company, develops an innovative technology to use solar energy. The product is an inflatable solar concentrator, called "HELIOtube", made solely out of inflated plastic foils. The pneumatic principle ensures a very efficient use of materials by its light weight construction. Furthermore, it gives stability and rigidity to the structure, in contrast to massive and hence expensive steel constructions as in the case of conventional parabolic troughs. As a result, the HELIOtube only needs about 5 kilograms of materials per square metre of concentrator surface. A parabolic trough in comparison weighs 130 kilograms per square metre of concentrator surface.Construction:The HELIOtube consists of a transparent upper, a reflecting middle and a robust lower foil. The reflecting foil separates the cylinder horizontally into two air tight chambers. Due to the pressure difference between the upper and lower chambers, the mirror foil is curved. The light enters first through the transparent upper foil and is then reflected and concentrated by the concave mirror foil onto the receiver.Advantages:The HELIOtube has the potential to reduce the costs of modern solar-thermal plants by 25 to 50 percent. The reasons for this advantage are the following characteristics:- Reduction of material usage of up to 95 percent- Light-weight structure with a cylindrical form with low wind resistance- Simple, fully automated production from reels