Abstract: A solar energy collector assembly is disclosed. The collector assembly includes an outer enclosure which has a light transparent major face adapted to face a light source and a plurality of walls extending rearwardly from the major face. A single collector plate is secured in the enclosure spaced from and rearward of the major face. The collector plate has a curvilinear configuration with a large radius of curvature. The collector plate has an outer surface adapted to face a light source and an opposite inner surface. A rear panel assembly which has an inner and an outer surface is attached in the enclosure rearward of the collector plate. A heating chamber is formed between the inner surface of the rear panel assembly and the inner surface of the collector plate. An inlet and an outlet communicate with the heating chamber to pass a transfer medium through the heating chamber. A control device is provided for controlling the rate at which a transfer medium is passed through the heating chamber.