Abstract: A solar energy collector includes a frustoconical reflective shell and a light converging lens. The frustoconical reflective shell includes a top opening and an opposite bottom opening. The reflective shell tapers from the top opening to the bottom opening. The reflective shell is configured for reflecting light. The light converging lens is arranged at the top opening and is fixed on the sidewall of the reflective shell. The light concentration lens includes a central lens portion and a periphery lens portion. The central lens portion includes a first light incident portion facing away from the bottom opening. The central lens portion includes a plurality of concentric annular prisms cooperatively forming a Fresnel-lens structure. The periphery lens portion is arranged surrounding the central lens portion. The periphery lens portion includes a convex second lens portion.

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: A solar energy collecting assembly useful for transferring solar heat to a heat utilizing system via heat transfer fluid flow, comprising anisotropic graphite sheets coupled to a pipe containing heat transfer fluid, and various configurations and embodiments. Methods useful for extracting collected solar heat and transferring said heat to a heat transfer medium.

Abstract: The radiation selective absorber coating of the invention includes two or more barrier layers arranged over each other on a substrate surface, an infrared-range reflective layer arranged on the two or more barrier layers, and at least an absorption layer arranged over the infrared-range reflective layer and a final antireflection layer arranged over the absorption layer. The absorber pipe, especially for a parabolic trough collector, is a steel pipe, on whose outer side the radiation selective absorber coating is applied. In the method of making the absorber pipe a first oxide barrier layer is provided on the outer side of the steel pipe by thermal oxidation, and then a second barrier layer, an infrared-range reflective layer, an absorption layer and a final antireflection layer are applied by gas-phase physical deposition.

Abstract: The solar absorber is equipped with an absorber body (10) that absorbs incident solar energy (12) and converts it to heat. The absorber body has a selective absorption layer (17) on a side (36) oriented toward the concentrator (13) and another selective absorption layer (18) on an opposite side (38) oriented away from the concentrator (13). The selective absorption layers (17, 18) have threshold wavelengths below which solar radiation is absorbed and above which a reradiation capacity of the absorber body is suppressed. The threshold wavelength of the selective absorption layer (17) on the side (36) of the absorber body that is oriented toward the concentrator is greater than the other threshold wavelength of the other selective absorption layer(18) on the opposite side (38) of the absorber body oriented away from the concentrator.

Abstract: The radiation selective absorber coating of the invention includes two or more barrier layers arranged over each other on a substrate surface, an infrared-range reflective layer arranged on the two or more barrier layers, and at least an absorption layer arranged over the infrared-range reflective layer and a final antireflection layer arranged over the absorption layer. The absorber pipe, especially for a parabolic trough collector, is a steel pipe, on whose outer side the radiation selective absorber coating is applied. In the method of making the absorber pipe a first oxide barrier layer is provided on the outer side of the steel pipe by thermal oxidation, and then a second barrier layer, an infrared-range reflective layer, an absorption layer and a final antireflection layer are applied by gas-phase physical deposition.

Abstract: The invention relates to a construction element that comprises at least one first transparent pane and a parallel second pane that is at least partly transparent and contains a material that accumulates latent heat. The material that accumulates latent heat is dyed or pigmented so that it absorbs light in the infrared range of the solar spectrum. The construction element claimed by the invention is highly efficient in absorbing light directly in the material that accumulates latent heat.

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 absorber-reflector is provided for solar heat transmission into a heat absorbing chamber and/or repelling back of solar heat resulting from incident solar radiation. The solar absorber-reflector is also suitable as a passive thermal control material for space applications, and consists of several layers. The minimal configuration includes three basic layers: a layer with a selective solar radiation absorbing surface, having high absorptance of solar radiation and low thermal emittance; a layer with a light-reflecting surface facing a direction opposite to the selective solar radiation absorbing surface; and a polymer film being transparent to visible light and possessing high thermal emittance, with a heat-emitting surface facing the same direction as the light-reflecting surface.

Abstract: A nonimaging solar collector. A method and article of manufacture of a solar collector includes an outer housing transparent to light, a reflector element positioned within the outer housing, an absorber concentrically disposed relative to the outer housing, and a heat conduction fin coupled to the absorber and having a wedge shape which tapers to a smaller thickness as a function of increasing radial separation from the absorber.

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 comprising a plurality of heat absorbing modules formed by deforming two plates into intimate contact with parallel metallic pipes disposed intermediate the plates. The plates are secured together by rivets which are spaced along and traverse the deformed portions of the plates, thus providing a spring section to absorb unequal expansion of the plates and the fluid conducting pipes. The uppermost surface of the pair of plates is provided with a black body coating to emit infrared radiation when sunlight is incident thereon. A glazing is provided over such black body surface to freely transmit incident light to the black body surface but to reflect infrared heat energy emitted by the black body surface. Water or other heat transfer liquid flowing through the pipes is maintained at a sufficiently high pressure to produce a turbulent flow through the pipes to increase the efficiency of the heat transfer.