An error model for functional tolerancing ofsolar collectors

The ultimate goal in the design of a parabolic trough solar collector is the minimization of electrical energy cost, to be achieved from a careful balance between equipment cost and amount of collected solar radiation. Core to this problem is an optimal allocation of tolerance specifications, which requires the ability to predict optical performance from allowable geometric errors on collector parts and assemblies. The paper describes an error model developed for this task. Compared to existing approaches, it aims at evaluating the functional effects of a wider set of geometric tolerances, thus allowing a better integration with engineering choices related to manufacturing and structural analysis.