A secondary reflector for receiving light from a plurality of primary reflectors that includes a reflecting surface having a length aligned along a first axis (z), where a cross-section of the reflecting surface in a plane perpendicular to the first axis (z) forms a curve comprising a concave section positioned between a first endpoint and a second endpoint, at least a portion of the concave section is accurately approximated by a polynomial equation, an aperture is formed by a straight line connecting the first endpoint to the second endpoint, and the concave section is configured to focus a plurality of beams of light passing through the aperture onto a focal point.

An aspect of the present disclosure is a device that includes a reflecting surface having a length aligned along a first axis (z), where a cross-section of the reflecting surface in a plane perpendicular to the first axis (z) forms a curve comprising a concave section positioned between a first endpoint and a second endpoint, at least a portion of the concave section is accurately approximated by a polynomial equation, an aperture is formed by a straight line connecting the first endpoint to the second endpoint, and the concave section is configured to focus a plurality of beams of light passing through the aperture onto a focal point.

A protective transparent enclosure, such as a greenhouse, encloses a concentrated solar power system having line-focus solar energy concentrators. The line-focus solar energy concentrators have a reflective front layer, a core layer, and a rear layer. The core and the rear layers, when bonded with the reflective front layer, enable the line-focus solar energy concentrator, in some embodiments, to retain a particular form without additional strengthening elements. In some embodiments, the core layer and/or the rear layer are formed by removing material from a single piece of material.

A CSP system including a reflector and a receiver for concentrating the solar radiation incident on the reflector onto the receiver, comprising a shadow blind and a shadow receiver as well as a colour and/or brightness digitizing sensor arranged to detect the shadow of the shadow blind on the shadow receiver in order to determine a deviation of the actual shadow position from a target shadow position, a tracking means configured to adapt the position of the reflector and the receiver according to the deviation.

Radiant energy traps are disclosed which comprise diffuse radiant energy concentrators with at least one reflector and receiver. A diffuse light concentrator (DLC) with optimizable flexibility may be used in multiple applications, such as solar electric, thermal (air or water), hybrid or a combination system.

An external concentrator is provided for use with heat collection elements (HCE's of a solar parabolic trough power plant. In one arrangement, the concentrator includes a plurality of ribs that are adapted to extend radially outward from the outside surface of an HCE and along the linear length of the HCE to help redirect stray/spilled light into the absorber tube of the HCE. In another arrangement, the concentrator includes a shield placed on or near a surface of the HCE opposite of the parabolic reflective trough. The reflective shield includes ribs or brims that are disposed adjacent to one or both lateral edges of a reflective shield applied to the outside surface of a HCE tube to increase the collection of stray light reflected by the reflective trough.

Methods of making a multilayer optical film are described. In one embodiment, the method comprises providing a multilayer optical film and disposing onto the multilayer optical film a plurality of layers deposited by layer-by-layer self-assembly of nanoparticles, polymers, and combinations thereof. The multilayer optical film typically comprises a plurality of alternating polymeric layers of a low refractive index layer and a high refractive index layer that reflects at least one bandwidth of electromagnetic radiation ranging from ultraviolet to near infrared. Multilayer optical film articles are described comprising a plurality of layers disposed onto the multilayer optical film, wherein the plurality of layers comprises layer-by-layer self-assembled nanoparticles, polymers, and combinations thereof. The multilayer optical films are suitable for various uses including reflective polarizers for optical displays such as LCDs or LEDs, architectural film applications, window film applications, and solar power concentrating mirrors.

Methods for preparing edge-sealed multi-layer film articles include applying a sealant composition to a multi-layer film article that includes at least one polymeric film layer, and permitting the sealant composition to dry to form an edge-sealed article. The sealant composition includes at least one solvent capable of softening, penetrating or dissolving the polymeric film layer of the multi-layer film article, and at least one polymer dissolved in the solvent. The polymer dissolved in the solvent may be a fluoropolymer, a non-tacky at ambient temperatures(meth)acrylate-based block copolymer, or a combination thereof. Edge-sealed articles prepared by this method can include other polymeric film layers or coated layers such as metallic layers and can be part of larger assemblies.

The invention relates to a heliostat sub-assembly and to a method of forming such a sub-assembly. The method of mounting a concave mirror to a supporting structure of a heliostat includes the steps of bonding a plurality of risers at predetermined spaced intervals to a rear face of the mirror, each riser having a bonding pad and a stem extending from the bonding pad, and applying a predetermined concave curvature to the mirror by conforming the front face of the mirror with a convex forming jig or die. The supporting structure and curved mirror are then aligned, and the supporting structure is clinched to the stems of the risers when the curved mirror is conformed with the forming die. The riser stems may be coupled to the bonding pads via multi-axial joint assemblies to enable limited multi-pivotal movement of the stems relative to the bonding pads to facilitate alignment of faces of the stems with the faces of the ribs defined by webs, and relative expansion and contraction of the mirror and supporting structure, the overlap between the riser stems and the webs being sufficient to accommodate clinching with variations in curvature of the glass sheet.

The present invention relates to a system for a parabolic solar concentrator (SCA) having a substantially continuous reflective surface aiming to maximize the efficiency of the parabolic solar concentrator and of its fabrication method. The system of the present invention allows the fabrication of a low cost parabolic solar concentrator, based on a torsion bar, ribs and a plurality of reflective pieces of sheet metal preferably covered with a reflective film. The parabolic solar concentrator according to a preferred embodiment allows the reduction of surfaces shading the reflective surface. Another advantage is the lack of presence of supporting or movement elements protruding in the concave side of the parabola, not including receiver tube components and supports, thereby increasing the reflection efficiency and solar collection.