A survey of solar concrete shell collectors for parabolic troughs

Concrete shell collectors offer an alternative to conventional parabolic trough collectors. The principle design concept is derived from existing barrel rooves that effectively bridge large spans in halls or buildings with minimum material usage. The concrete troughs merge the bearing structure and mirroring surface to just one shell of a few centimeters. They are made of high-strength concrete and track the sun via pure axial rotation or lateral movements that avoid any lifting works. In the present contribution, basic constraints in materials, geometry, and static calculation are derived and converted into a framework of possible designs. This contribution thereby presents a survey of concepts that range from small-scale prototypes to full-scale realizations of 140 m2 apertures and large-aperture concepts with a 10 m width. Design concepts with bearing and drive systems as well as optimization-based form findings are introduced to elaborate shells of minimum weight with solid sections, stiffeners, and hollow cores.