Abstract: The method for coating a substrate with silver nanoparticles includes reducing a silver nitrate solution with an ethanol extract of the traditional Indian medicinal plant (Curcuma Longa L.), a naturally abundant antioxidant, to form a final solution, and contacting the final solution with the substrate to provide the silver nanoparticle coating. Formation of the silver nanoparticle coating on the substrate can be determined when a mirror in the final solution is observed. The thickness of the coating layer can be less than 125 nm. The coated substrates can be highly conductive.

Abstract: Techniques, systems, devices and materials are disclosed for spectrally selective coatings for optical surfaces having high solar absorptivity, low infrared emissivity, and strong durability at elevated temperatures. In one aspect, a spectrally selective coating includes a substrate formed of a light absorbing material, and a composite material formed over the substrate and including nanoparticles dispersed in a dielectric material, in which the composite material forms a coating capable of absorbing solar energy in a selected spectrum and reflecting the solar energy in another selected spectrum.

Abstract: A method (100) for manufacturing a thermal absorber for a solar thermal collector includes arranging (120) a substrate of the thermal absorber on a vacuum coating line and depositing (160) by way of a physical vapour deposition on the substrate that is arranged on the vacuum coating line layers configured to absorb light.

Abstract: A passive radiative cooling system in which an ultra-black emitter includes metamaterial nanostructures disposed on the top surface of a metal sheet, and a conduit structure channels the flow of coolant against a bottom surface of the metal sheet. The metamaterial nanostructures (e.g., tapered nanopores) are configured to dissipate heat from the coolant in the form of emitted radiant energy having wavelengths/frequencies that fall within known atmospheric transparency windows (e.g., 8-13 ?m or 16-28 ?m), the emitted radiant energy being transmitted through a reflective layer into cold near-space. The ultra-black emitter is formed using a modified Anodic Aluminum Oxide (AAO) self-assembly technique followed by electroless plating that forms metal-plated tapered nanopores, and the reflective layer includes a distributed Bragg reflector.

Abstract: A system for enhancing evaporation from a body of liquid, in which heated or unheated air is distributed through a pipe network that is submerged in the evaporation pond, with the air being injected into the pond to produce air bubbles in the water. The air may be combined with water prior to the injection. The water may be drawn from the pond. The air and/or water may be heated by solar heating, electric heating, fuel burning, or waste heat recovery. In the case of solar heating, any of a transpired solar collector, a packed bed solar collector, a flat plate solar collector, a linear Fresnel collector, a parabolic solar collector, a paraboloid dish solar collector, or other could be used. The pipe network may be maintained at a desired depth below the upper surface of the pond by various means, with one example being flotation devices, from which the pipe network is suspended.

Abstract: A structure, which can be used as a portable shelter or tent, has a cover and structural elements disposed therein to permit the cover to lay flat or stand erect. The cover has two layers, one layer being thermally reflective and another layer being thermally absorptive. Similarly constructed removable panels can be attached to standoffs incorporated into the cover. The structure is reversible, so that the structure can either reject or absorb ambient heat. The standoffs are provided on each side of the cover and connections for attaching the removable panels to the standoffs are provided on each side of the removable panels. In this way, the removable panels can be attached to the interior or exterior of the structure with either side of a removable panel facing towards the cover.

Abstract: A solar energy reflector (1) comprises a mirror (5) with no copper layer laminated to a supporting sheet (7) by means of a bonding material (6). The edges of the mirror (5) are provided, at least on a portion forming the major part of their height and closest to the metallic sheet, with an edge protection (8) made of a material comprising silicone, polyurethane and/or acrylic and the material forming the edge protection (8) is different from the bonding material (6).

Abstract: A solar selective coating includes a substrate, a cermet layer having nanoparticles therein deposited on the substrate, and an anti-reflection layer deposited on the cermet layer. The cermet layer and the anti-reflection layer may each be formed of intermediate layers. A method for constructing a solar-selective coating is disclosed and includes preparing a substrate, depositing a cermet layer on the substrate, and depositing an anti-reflection layer on the cermet layer.

Abstract: An antireflective structure having a higher antireflective effect compared with those of conventional antireflective structures is produced by a simple process. The antireflective structure (10) includes a plurality of concavities (2a) each having a plurality of convexities (1a) thereon, and a pitch between the plurality of convexities (1a) and a pitch between the plurality of concavities (2a) are smaller than a wavelength of light incident to the antireflective structure (10).

Abstract: A solar receiver device includes a metal conduit and a glass container disposed around the metal conduit such that there is a space between the glass container and the conduit. A coating is disposed on the metal conduit and has a composition that includes at least one element from silicon, titanium, aluminum, barium, and samarium.

Abstract: The heat reflecting arrangement with an improved high heat resistance, e.g. 100 hours at 500° C., includes a substrate, a heat reflecting layer (A) on at least one side of the substrate, which contains indium tin oxide (ITO), and a barrier layer (B) that covers the heat reflecting layer (A), which contains a metal oxide and/or a metal nitride. A fireplace or baking oven with a viewing window having this layer system with the heat reflecting layer is also described. In addition a process for providing the heat reflecting arrangement is described.

Abstract: The present invention provides a solar absorptive material for a solar selective surface of an absorber of solar radiation. The solar absorptive material comprises a dispersed metallic material and a receiving boundary through which the solar radiation is received. Further, the solar absorptive material comprises a first region and a second region. The first region being located at a position closer to the receiving boundary than the second region and the first region has an average volume fraction of the dispersed metallic material that is larger than that of the second region.

Abstract: Described are methods for surface modification of an object (10) in order to increase the adhesive power of the object, wherein the surface (11) is subjected to structuring so that a multitude of projections (12) are formed, each comprising a foot part and a head part, wherein the head part comprises a front surface (13) which faces away from the surface, wherein each projection (12) is made in a size such that all front surfaces (13) project to the same vertical height above the surface (11), and form an adherent contact surface (14) which is interrupted by mutual spacing between the front surfaces (13).

Abstract: In a flat panel solar collector adapted to be evacuable and vacuum-tight, at least one absorber is provided. At least one conduit is provided which is at least partially thermally associated with the at least one absorber. A holding structure is provided comprising a perimetric frame. At least one first transparent wall is provided, the first transparent wall and the holding structure having a overlapping area. At least one side of the first transparent wall comprises at least partially at said overlapping area a metal coating forming at least one metallized area on the transparent wall. A first soft metal ribbon is provided sealing the junction between the first transparent wall and the holding structure and which is soldered to the holding structure and to the metallized area of the first transparent wall.

Abstract: The invention relates to a solar collector element having an absorber part and a tube for a heat transfer liquid connected thereto on a first side. The absorber part consisting of a composite material having a metallic substrate and an optically active coating on a second side of the substrate. The coating is a multilayer system having three layers. The top layer is a dielectric layer, preferably an oxide, fluoride or nitride layer of chemical composition MeOz, MeFr, MeNs, having a refractive index n<1.8. The middle layer is a chromium oxide layer of chemical composition CrOx. The bottom layer is gold, silver, copper, chromium, aluminium and/or molybdenum. The indices x, z, r and s indicate a stoichiometric or non-stoichiometric ratio in the oxides, fluorides or nitrides.

Abstract: A solar collector for absorbing solar energy and for conversation thereof into thermal energy includes an aluminum foil. One side only of the aluminum foil is blackened to an extent such that it will absorb solar energy, preferably to an extent approximating a black body. The blackening is achieved by subjecting the one surface of the aluminum foil to an electrochemical surface etching treatment.

Abstract: A solar heat collecting apparatus includes a first, inner glass dome, and a second, larger outer glass dome disposed outwardly from the inner dome. Both of the inner and outer domes have respective inner and outer surfaces and an open end, and an infrared reflective coating is adhered to the inner surface of the outer dome. A solder glass seal joins the open ends of the inner and outer domes together, thereby forming a void between said inner and outer domes. Means are provided for rechargeably forming a vacuum in the void, and an absorber plate is disposed beneath and covered by the inner and outer domes. Solar radiation entering the solar heat collecting apparatus according to the present invention is absorbed by the absorber plate, and transferred to a remote storage system by conventional heat transfer means, such as an array of conduits placed in thermal contact with the absorber plate and containing a suitable fluid.

Abstract: A flat plate solar collector comprising a planar glazing and a rear housing formed into a number of semi-circular cells to receive fin-tube absorbers with minimal direct contact, the glazing being a low iron glass with an anti-reflective exterior coating and a low emissivity interior coating, the glazing being directly supported by the rear housing cells, the interior wall of the rear housing and the lower side of the fin-tube absorber having low emissivity surfaces. At least one radiation shield member having low emissivity upper and lower surfaces is positioned between the fin-tube absorber and the rear housing. The collector is evacuated by atmosphere control means also capable of reintroducing atmosphere into the collector to control internal temperature.

Abstract: Solar energy absorptive coatings that comprise single cermet layers with a homogeneous metal volume fraction exhibit an absorptance of about 0.8, which is not high enough for practical solar applications. To achieve absorptance greater than 0.9, graded composite films have been developed, but they give rise to higher thermal emittance due to the absorption edge not being sharp enough. This leads to increased thermal emittance at high operating temperatures, in the range of 300.degree. C. to 500.degree. C. There is now disclosed a novel solar selective surface coating which is composed of two cermet layers, with different metal volume fractions in each layer. The two cermet layers have different thicknesses, and the layers have thicknesses and volume fractions such that solar radiation is absorbed by internal absorbing and phase cancellation interference, but the cermet layers are substantially transparent in the thermal infrared region.

Abstract: A solar energy collector whereby an absorber plate thereof is formed by providing a thin metallic foil for supporting sprayed molten metal, arranging fluid carrying tubes on the foil, and spraying molten metal using a source of pressurized inert gas onto a substrate and tubes to build up a coating of sufficient thickness to form a unified solar collector panel comprising the absorber plate, embedded tube and foil which have good thermal contact with each other. The method further includes forming a selective surface on the sprayed metal absorber plate.