Device for the concentration of solar radiation

A device for concentration of solar radiation in an absorber, said device comprising an inflatable concentrator cushion having a cover film element with a light-permeable entry window for coupling in solar radiation and a reflector film for concentration of solar radiation in an absorber, the reflector film sub-dividing the concentrator cushion into at least two hollow spaces and having a curvature in an inflated state. The device also comprises a pivoting apparatus, with which the concentrator cushion is pivotable, a retaining apparatus secured to the pivoting apparatus, and an adjusting device for adjusting the curvature of the reflector film. The retaining apparatus comprises a lower longitudinal member which is connected to a bottom film element of the concentrator cushion. The adjusting device comprises a tensioning element between the lower longitudinal member and the reflector film, said tensioning element being connected to the reflector film and to the lower longitudinal member.