MULTIFOCAL CONDENSER FOR ELEMENT FOR CONVERTING SOLAR RADIATION INTO ELECTRIC, HEAT OR CHEMICAL ENERGY

摘要

PROBLEM TO BE SOLVED: To provide a transmission condenser having a high conversion efficiency value (≥80%), in which the distribution of multi-color irradiance on a cell surface becomes uniform.

SOLUTION: The condenser can propagate solar radiation to the surface of a conversion element. The condenser 10 is provided with at least one part of a Fresnel lens having rotational symmetry, and one surface 11 of it is provided with a plurality of peaks 12 arranged concentric to the center so as to form a transversal profile sectioned for the part of the Fresnel lens. The profile is formed so as to vary the focus distance of the Fresnel lens, depending on a radius distance from the lens center. When the Fresnel lens is irradiated with multi-color radiation, the change of the focus distance is decided so that the overlapping of the distributions of the irradiance is generated by the lens by individual wavelengths constituting an incident radiation spectrum and practically uniform multi-color irradiance distribution is generated in the conversion element.

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