Solar energy conversion

Abstract

Apparatus and methods for concentrating and collecting solar energy are disclosed. In accordance with the invention, solar energy is concentrated by economical refringent lenses or lens systems including fluid lenses and/or Fresnel-type lenses. The lenses concentrate the solar energy preferably along lines in continuous linear foci or in discrete foci at an elongated collector comprising one or more fluid-carrying conduits and one or more fluids therein. In one embodiment, a plurality of photoelectric cells are located in or on the collector along the linear foci or at the discrete foci and operate at increased efficiency with heat being removed by the collector. A first fluid in the collector is heated by the concentrated solar energy and in a preferred embodiment is used to heat a second fluid contiguous to the first fluid, the first fluid having a boiling point exceeding that of the second fluid. In a preferred embodiment, the first fluid is carried in an inner conduit while the second fluid is carried by an outer conduit which encloses the inner conduit and first fluid. Thus, the two fluids can be heated to different temperatures by a single concentrating system and used for different purposes.