is lt u03b3 lt u03b1 lt u03b2 in the northern hemisphere the panel distal to the sun 39 s path that is panel 13 is disposed at an angle equal to the angle of incidence between the sun 39 s rays and the earth relative to the latitude in which the collector is located at the winter equinox plus 5 u00b0 15 u00b0 whereas the panel proximal to the sun 39 s path that is panel 12 is disposed an angle equal to the angle of incidence between the sun 39 s rays and the earth relative to the latitude in which the collector is located on the summer equinox plus 5 u00b0 15 u00b0 of course in the southern hemisphere the positioning of the panels relative to the equator will be reversed referring to fig3 the panel facing surface of each panel for example surface 25 of panel 13 covered with a plurality of highly reflective convex receptors 26 preferably produced in a series of parallel strips 27 each receptor 26 is like every other receptor disposed on the respective panels 12 13 and in its preferred form will have a convex curvature formed by an arc having a chord approximately equal to three fourths of the diameter of the circle from which it is formed in one practice of the present invention each receptor 26 in each strip 27 is formed with a body 28 of extruded aluminum over which a highly reflective plastic film 29 such as.