Solar energy converter using photovoltaic cell - has convergent lens centrally located in toroidal reflector of parabolic form

摘要

In the solar enery converter, the optical system comprises a central lens (13) surrounded by an annular toroidal mirror (14), both on the same side of a flat photo-voltaic cell (11) as the sun. The lens concentrates the solar rays onto the cell. The mirror cross-section is of parabolic form, with the ratio of its max. dia. to that of the lens being approximately the square root of 2. The mirror is formed by a metallised coating (31) on the inside of a container similar to that used for a cathode ray tube. The flat upper surface (30) enables the peripheral rays (19) to enter and to be reflected onto the cell. The converter forms an electrical voltage output across the cell as a consequence of the solar energy received. The use of a lens in conjuction with the reflector enables peripheral rays to be collected so that it is not essential for the axis of the optical system to be aligned exactly with the sun, and allows more tolerance in the mechanical drive arrangement.