Predicted daily and yearly average radiative performance of optimal trapezoidal groove solar energy collectors

Abstract Some possible applications of solar energy (e.g. absorption cooling, process heating and preheating, unconventional power production) require heat at temperatures above those associated with flat-plate collection but below those usually associated with sophisticated focusing collectors. Collection temperatures in this range may be economically obtained using moderately concentrating, nonfocusing, trough-like collectors. Such a collector is one composed of East-West aligned, parallel, trapezoidal grooves. Practical concentration ratios up to 3 can be attained with the direct component of insolation while at the same time capturing a significant portion of the non-direct component. In this paper the daily and annual radiative performance of grooved collectors with depth-to-base ratios ranging from 1.1 to 5 are presented. The results are based on assumed tilting routines chosen to match the collector's capabilities.