PREDICTED DAILY AND YEARLY AVERAGE RADIATIVE PERFORMANCE OF OPTIMAL TRAPEZOIDAL GROOVE SOLAR-ENERGY COLLECTORS

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. © 1979.