A solar tracking system has a first set of solar heat gain transducers (700) that produce respective first output signals to drive a reversible first motor (300) for changing a vertical angle of a solar collector (200); and a second set of solar heat gain transducers (700) that produce respective second output signals to drive a reversible second motor (608) for changing a horizontal angle of the solar collector (200); each of the transducers (700) having a thermistor (702) in thermal contact with a thermal mass (706); and a communications apparatus (900) receiving output voltage from solar cells (202) on the solar collector (200).