Abstract: A solar collector venting system comprising a lower frame member with vents which allow the entrance of cooling air when high collector stagnation temperatures occur communicating with the natural downward thermal bowing of a two walled plastic glazing caused by differences in coefficients of expansion between the cooler upper layer and the hotter inner layer of plastic glazing communicating with an upper frame member with stationary fulcrum points communicating with vents in between the fulcrums points which, upon bowing of the glazing cause the upper end of the glazing sheet to lift up off the top frame member allowing an open path for the flow of cooling air to pass up thru the collector between the absorber and the plastic glazing whose path may be kept clear by communicating with flow path spacers on the absorber.

Abstract: A solar boiler of improved energy efficiency that includes a solar panel for receiving solar energy and converting a liquid to steam and a highly accurate tracking system to maintain the panel substantially perpendicular to the sun. The panel includes a plurality of heat transfer liquid carrying tubes having a highly absorptive coating over areas receiving solar energy and high efficiency insulating material over remaining surface areas. An extruded compound concentrating cylindrical lens is positioned over each tube to concentrate received solar energy along a narrow linear energy receiving area. Each panel is mounted for rotation and tilting on a simple, sturdy base. Each panel is substantially closed but includes openings designed so that some air flow through the panel is permitted to prevent excessive heat within the panel while preventing entry of moisture.