Abstract: Solar energy collector construction wherein the collector is composed of a skeleton framework, preferably of I-beam configuration interconnected so that it may be folded into a compact configuration for storage and shipment and which may be erected and locked into expanded configuration at the erection site so as to provide a sturdy structure which is highly resistant to wind loading and yet is fully effective in operation and use. Another feature is the design and mounting of the reflective elements which permits the reflective elements to be replaced periodically as they become less efficient reflectors through exposure to the elements. An improved collector construction is disclosed wherein the absorber element is in the form of a plate having passages therein for the flow of heat exchange fluid therethrough, the absorber plate being mounted within an enclosed light- and radiant-energy-transparent envelope which minimizes loss of heat from the absorber element by convection and conduction.