Structure for conversion of solar radiation to electricity and heat

Claim 1

In a flat form solar collector, for collecting and absorbing solar radiation and conversion of said radiation to heat, comprising (1) a flat thermal collector plate having an upper surface that has a high absorptivity, at least 0.8, for electromagnetic radiation of wave lengths of 0.3 to 2.1 microns and converts such radiation on absorption largely to heat and (2) one or two superimposed enclosed insulating spaces above said thermal collector plate, each space being defined by a light conducting plate, the whole being sealed or enclosed about the periphery to form one or two spaces above said thermal plate isolated from the ambient atmosphere, the improvement wherein at least the light conducting plate immediately above said thermal collector plate is a luminescent solar collector and concentrator comprising a radiation collection medium for receiving incident solar radiation, wherein said radiation collection medium is a composite structure comprising: (a) a thin layer, containing at least one luminescent species capable of emitting luminescent radiation upon excitation with incident solar radiation, optically and physically coupled to (b) a relatively thick radiation conducting layer having an index of refraction close to that of said thin layer, said radiation collection medium being (i) totally internally reflective of a major portion of said emitted luminescent radiation, (ii) transparent to a portion of said incident solar radiation including visible wavelengths and (iii) optically coupled, in a relatively small portion of the surface area of said thick layer, to a photovoltaic cell responsive to said emitted luminescent radiation, said thin layer containing said luminescent species being within one of said enclosed insulating spaces, whereby in operation a portion of said luminescent radiation is conducted to said solar cell to produce electricity, and unabsorbed solar radiation including visible wavelengths plus a minor portion of said luminescent radiation is transmitted to said thermal collector plate and largely converted to heat, and whereby said thin layer is protected from the ambient environment and from direct contact with said solar cell.