A self-powered sun tracking system based on a novel lignt direction sensor

We present a self-powered solar tracking system which can automatically adjust the location of the solar panels to optimize the energy harvesting. The solar panels supply power to the entire system, so there is no additional power. The solar panels, a motor, and a CMOS chip constitute the system. Considering the size and the cost, the new sensor and its circuit are integrated in a chip that is implemented by a standard 0.5µm process. We tested the system under the sun. The results indicate that the system is sensitive to the change of light direction and in a optical power range of 30–110 mW/cm² the tracking accuracy can be as good as 1.8 degrees.