Abstract: The present invention provides a solar collector apparatus, comprising a horizontally-mounted cylindrical reflector, divided along its length into two reflector segments, each having its own axis of rotation. Preferably, the two reflector segments are produced by dividing the horizontally-mounted cylindrical reflector down its centerline into two equal reflector segments. The two reflectors segments perform novel tracking with different rotation angles about their corresponding axes by use of a trapeze coupling or a mechanism that permits separate tracking. Since the two reflector segments are coupled, preferably only one tracking mechanism (trapezoid or other) is required since the reflector segments preferably have parallel axes. The present invention also provides a stationary preferably flat plate receiver facing downwards, absorbing the solar energy reflected upwards.

Abstract: A solar collector including an absorber having at least one channel for conducting a fluid receiving the heat absorbed, a housing enclosing the absorber and having radiation-transparent windows covering and spaced from both faces of the absorber, and partition members disposed between the absorber and the housing and effective to block the circulation of air flowing in the space between one face of the absorber and the housing from flowing to the space between the other face of the absorber and the housing, to thereby reduce convection losses from the absorber.

Abstract: A solar collector, comprises: a tubular housing of radiation-transparent material hermetically closed at one end; a smaller-diameter tubular absorber having a radiation-absorbing surface, the absorber being coaxially disposed within the tubular housing and hermetically closed at one end; the opposite ends of the tubular housing and absorber being sealed together, and the space between the two being evacuated; and heat-extracting means for passing a heat-exchange medium through said opposite end of the tubular absorber into the interior thereof to extract heat therefrom.