As an external shading facility for buildings, a new energy-saving external shutter is presented, which is intelligently controlled and without external power supply. The slats are driven by a motor which is powered by the third generation thin-film solar cells. The signals, which are measured by wind, light, rain and temperature sensors, are processed by a microcontroller system controlling the motor. According to a quick-response and high-efficiency control strategy, the movement of shutter is r...