sun such silicon photovoltaic cells as 2cm 2 10 ohm cm single crystal cells by ocli have been found to be satisfactory in an exemplary embodiment the base 16 is a disc about 14 inches in diameter and is affixed to the mount 18 which is a simple bar which may in turn be mounted on the solar collector the base serves as a platform for carrying photocells 22a 22b 22c and 22d and for mounting support or shade horn 20 shade horn 20 is shown in the shape or configuration of an inverted truncated pyramid for convenience the wide portion of the inverted pyramid may be thought of as the top and the narrow portion of the pyramid may be thought of as the bottom in the exemplary embodiment the bottom of the pyramid which may be mounted in the center of the base 16 is a square with sides of about 0 7 inches the top of the pyramid on which is carried photocell 26 is shown as a square with sides of about 2 7 inches on each wall of the pyramid is mounted a photocell 24a 24b 24c and 24d the altitude of the exemplary pyramid is about 4 inches reference is now made to fig3 which illustrates the solar tracker 14 in side.