Abstract: A fixed position concentrating solar collector in the form of a trough having an inner surface reflective to solar radiation and formed to direct the sun's rays entering the trough onto a radiation absorber element, the trough having end structures capable of selectively reflecting solar radiation into the trough or of being made transparent for passing solar radiation into the trough which would otherwise be blocked off by the trough end. Devices responsive to the position of the sun relative to the trough automatically control clearness-reflectiveness of the trough ends. End structures include flexible sheets on a roller, movable ends, jointly movable slats, leaves which may be aligned or fanned out, inflatable bags and flexible sheets controlled by bourdon tubes. A highly efficient configuration of the trough reflecting surface has a transverse plane profile defined by a compound parabolic curve comprising a half parabola joined to the other half of the parabola by a quarter circle shifted 90.degree.

Abstract: Processes and apparatus for storing solar energy in synthetic fuels are disclosed. The disclosed processes include the steps of introducing steam and carbonaceous material such as coal, lignite, peat, solid organic wastes, or heavy oils into a molten gasification medium such as one or more molten salts and supplying sufficient solar heat to the gasification medium to maintain it in the molten state at a temperature at which the carbonaceous material and steam react to produce a synthesis gas product including a synthetic fuel gas or gases. Disclosed processes include the step of adding solar absorptivity enhancing dopant material to the gasification medium. Disclosed processes include the step of supplying solar heat to the gasification medium by directing concentrated solar radiation onto the gasification medium, rather than directing the solar radiation onto a separate body of material for indirectly heating the gasification medium.