Abstract: The solar concentrator system includes a generally parabolic-shaped primary reflector having a flat region at the center thereof, so that the focus of the primary reflector is a ring about the center axis of the reflector, in the plane of the rim thereof. A receiver, in the shape of an inverted, truncated cone, is positioned so that the peripheral surface of the receiver is approximately coincident with the ring focus. Solar cells are positioned in lines on the peripheral surface of the receiver. Prefilter tubular secondary concentrator elements are positioned just in front of the lines of solar cells, providing an additional focusing capability and improving the concentration of the solar rays, while being spaced sufficiently that the unilluminated areas between the lines of solar cells can accommodate electrical interconnectors.

Abstract: The present invention provides a photovoltaic module for converting solar energy into electrical energy. The module comprises a substrate having a relatively large first surface and a relatively small second surface. A first photovoltaic cell is mounted to the first surface, the first photovoltaic cell having a first response band. The module is positioned such that the solar energy is incident onto the active area of the first photovoltaic cell. A second photovoltaic cell substantially smaller than the first photovoltaic cell is mounted to the second surface of the substrate. The substrate is formed such that a portion of the solar energy transmitted by the first photovoltaic cell into the substrate is directed onto the active area of the second photovoltaic cell. Because of the smaller area of the second photovoltaic cell, the cost per unit cell area is lower than in conventional tandem cell designs.

Abstract: A solar energy system that includes a primary concentrator, a receiver having a plurality of photovoltaic cells, and a prefilter surrounding the receiver. The prefilter absorbs some of the radiation that is out of band with respect to the photovoltaic cells, and may include a conduit for a cooling fluid. The cells on the receiver are positioned such that each cell receives the same solar energy flux. The receiver may include a phase change material to protect the photovoltaic cells from excessive temperatures.