ORIENTATION OF STATIONARY AXIAL COLLECTORS

Attention is drawn to the fact that stationary solar collectors with axial symmetry have a third degree of freedom which must be considered, in addition to their azimuth and tilt angles, if their orientation is to be optimized on an annual or seasonal basis. We set up the equations needed to describe collector orientation in terms of all angles, including this extra degree of freedom which we refer to as "skewness." Examples of the use of these equations are then given, both for northern and southern latitudes, which illustrate the manner in which skewness may be taken into consideration and highlight the importance of doing this. For the sake of simplicity the illustrative examples treat only the direct beam component of the total insolation intercepted by the collector.