Linear Solar Concentrator Structural Optimization Using Variable Beam Cross Sections

Abstract

The design and construction of solar concentrators heavily affects their optical efficiency, heat utilization, and cost. Current trough concentrators use an equivalent uniform beam with a metal grid substructure. In this conventional design, there is surplus stiffness and strength, which unnecessarily increases the overall weight and cost of the structure. This paper describes a variable cross section structural optimization approach (with the EuroTrough design, including safety factors, taken as an example) to overcome this issue. The main improvement of this design comes from keeping the beams rigid and strong near the two ends (at the torque box structure) while allowing the middle of the structure to be relatively weak. Reducing the cross-sectional area of the middle beams not only reduces the amount of material needed for the structure but also reduces the deflection of the reflector. In addition, a new connection structure between two neighboring concentrator elements was designed to reinforce the structure. The simulated results show that the concentrator's structural weight (including the torque box, endplates, and cantilever arms) is reduced by 13.5% (i.e., about 133 kg per 12 m long element). This represents a meaningful capital and installation cost savings while at the same time improving the optical efficiency.