Abstract: A system for cleaning solar panels (photo-electric and/or water heating etc.) is driven by fluid driven motor (water and/or air driven motor) such as a piston motor or a vane motor. Some or all of the outlet water/air from the motor is used for cleaning the panels. The motor preferably also operates a cleaning mechanism, such as a rotating and or linear brush arrangement. The motor, gear system and/or components may be made from plastic. Optionally, a cleaning device travels along the edges of panels, optionally without requiring an additional rail structure. The cleaning device optionally includes a trailing water/air supply hose. In some embodiments, electrical components of the cleaning device are powered by an internal power supply. Control is optionally via an electrically actuated valve, a timer (for example a real time clock), a wireless receiver and/or a controller.