Abstract: A cable drive system for solar tracking for solar array systems. The cable drive system employs one or more cables wound around a drive pulley of a drive device and one or more driven pulleys of respective rotatable solar assemblies of the solar array system. The system may use a tension device such as a spring or weight that returns the solar array system to an initial position at the end of the day. The drive device may be an active or passive solar tracker. The disclosed techniques of rotating solar panels are flexible, inexpensive, and reliable. The techniques can apply to any solar technology that benefit from following the sun.

Abstract: A solar tracking device that uses thermal actuation to rotate a solar energy device to track movement of the sun for improved solar energy output of the solar energy device. Thermal actuation is generated by concentrating solar radiation using a solar collector and solar receiver. A medium that expands when heated is in thermal communication with the solar receiver and drives an actuator for rotating the solar tracking device to follow the movement of the sun. The medium may be a phase change material such as Paraffin wax. Rotational actuation may be performed using helical slots in a main housing and cam followers coupled to a shaft extended out of the main housing. At the end of the day, a combination of gravity and/or mechanical return forces may assist in returning the system to an initial position such that it is ready to receive solar radiation the next day.