A solar energy concentrating collector having a frame with bottom, end and side panels of corrugated material adapted to include secondary side panels that are folded inward and have vertical slots for containment of parabolic supports for a flexible reflective surface placed on top of the supports. Frame end panels have apertures located on the parabolic focal line for connection of fluid conduits outside the frame. For arrangement in solar collector arrays, conduit apertures in end-to-end mounted collectors are aligned to receive a common absorber pipe that extends through and beyond a plurality of collector frames for external connections to conduits in the next adjacent parabolic reflective surface parallel to the first reflective surface in the same frame. Supports for the reflective surface have parabolic cutouts in the top portion and are processed as multiple side by side components in a corrugating machine. The preferred material is corrugated paperboard.

The present invention is a cross-sectional arrangement for solar concentrators which is comprised of a concave reflective boundary, of at least two receiver-converters residing within the concavity, and of additional reflecting means within the field-of-sight of the concave reflective boundary and, preferably, within the confine of the reflective boundary.

A generally rectangular tensioned cover comprises a pair of end forms having end portions. They are generally parallel along their lengths. A pair of side rails which are generally orthogonal to the end forms have first and second end portions. They are spaced substantially the lateral separation of the end forms with the end portions of each side rail positioned adjacent the end portions of an end form. A tensionable sheet spans from one side rail to the other and from one end form to the other. The sheet's first end portions are attached along the end forms. The lateral peripheral portions of the sheet are attached along the side rails. The end portion of the one end form is fastened to the first end portions of the side rails. The end portion of the other end form is fastened to selectable regions of the second end portions of the side rails. The sheet is tensioned longitudinally between the end forms.

A device efficiently collects energy from a moving source without having to actively track the source. The device includes a primary concentrator, a secondary reflector and a target position. The primary concentrator is positioned to receive energy from the moving energy source and to direct the energy toward the secondary reflector. The secondary reflector has a concave surface which is covered by a number of convex reflecting surfaces. These convex reflecting surfaces direct the energy toward the target position regardless of the relative angle between the energy source and the primary concentrator.

A new small skylight which can be installed in buildings in general, on the roof of rooms requiring natural lighting. The advantage of this skylight over previous ones lies in its small size, thus avoiding having to make a wide roof opening for installation, with the consequent risks and dangers involved. An external reflecting flat sheet rotating with respect to a transverse axis placed on the top base of a vertical light conduit tube. The tube intercalated by a jacket tube, goes through the roof. The external reflecting sheet sends the collected light beams to a mirror, which is tilted on the vertical tube, the interior surface of the tube being capable of receiving and sending towards the interior of the room he reflected light beams received from said mirror. Another embodiment allows the user to regulate the external reflector operative tilting, as well as to rotate respect to a vertical axis to achieve for the best orientation relative to the sun.