System and method for cleaning a solar row of solar panels. The solar row has an upper edge elevated from ground level more than a lower edge to provide an inclination of the solar row. A cleaning assembly operates to clean a surface of the solar panels. A support frame supports the cleaning assembly and enables the cleaning assembly to move (1) upwardly and downwardly in the width direction of the solar row, and (2) in the length direction of the solar row. Operation and movement of the cleaning assembly is controlled by a control unit to cause the cleaning assembly to clean a surface of the solar panels during downward movement of the cleaning assembly. The cleaning assembly is preferably not operative during its upward vertical movement. During the downward movement, the cleaning assembly removes dirt, debris and dust from the surface of the solar panels and generates an air stream to blow off the dirt, debris, and dust.