Dual-Axis Solar Tracker Design Based on a Digital Hemispherical Imager

A design of a solar tracker with a new tracking method based on computer vision techniques is presented in this paper. The proposed method extracts the sun position (orientation θ, elevation φ) in real time from hemispherical sky images using a processing techniques and then drives a pair of motors to move solar panels (or heliostats) toward the sun. To ensure a wide field of view, a camera equipped with a fisheye lens is used to acquire whole sky images. The advantages of such a system are the high sensitivity to brightness compared to traditional photosensors-based trackers. Thus, the system becomes more efficient and able to determine the sun position even during cloudy days. It also operates independently of time and position which makes it reliable in case of mobile solar stations, contrary to systems based on astronomical equations.