A solar thermal energy device is provided. Also provided is a method of making a solar thermal energy device.

A heat receiver tube for absorbing solar energy and for transferring the absorbed solar energy to a heat transfer fluid is provided. The heat receiver tube includes a first partial surface, which is covered by a solar energy absorptive coating, and a second partial surface, which is substantially uncovered by the absorbing coating. Also provided is a parabolic trough collector with a parabolic mirror having a sunlight reflecting surface for concentrating sunlight in a focal line of the parabolic minor and a heat receiver tube which is arranged in the focal line of the parabolic mirror, wherein the heat receiver tube is arranged in the focal line such that the first partial surface with the solar absorptive coating is at least partially located opposite to the sunlight reflecting surface and the second partial surface at least partially averted to the sunlight reflecting surface.

A solar thermal collector and an accessory structure of a building are provided. The solar thermal collector includes at least one heat absorbing plate and at least one heat insulating plate. Each of the heat absorbing plate includes at least one first slab and first engaging parts connected with the first slab. Each of the heat insulating plate includes at least one second slab and second engaging parts connected with the second slab. The first engaging parts are respectively engaged with the second engaging parts, and a gap is maintained between the first slab and the second slab to define a heat collecting channel, through which a heat transfer medium flows between the heat absorbing plate and the heat insulating plate. A heat conductivity of the heat absorbing plate is at least 30 times greater than a heat conductivity of the heat insulating plate.

There is provided a heat resistant ferritic steel including a base material including, by mass percent, C: 0.01 to 0.3%, Si: 0.01 to 2%, Mn: 0.01 to 2%, P: at most 0.10%, 5: at most 0.03%, Cr: 7.5 to 14.0%, sol.Al: at most 0.3%, and N: 0.005 to 0.15%, the balance being Fe and impurities, and an oxide film that is formed on the base material and contains 25 to 97% of Fe and 3 to 75% of Cr. This heat resistant ferritic steel is excellent in photoselective absorptivity and oxidation resistance.

There is provided a heat resistant ferritic steel including a base material including, by mass percent, C: 0.01 to 0.3%, Si: 0.01 to 2%, Mn: 0.01 to 2%, P: at most 0.10%, S: at most 0.03%, Cr: 7.5 to 14.0%, sol.Al: at most 0.3%, and N: 0.005 to 0.15%, the balance being Fe and impurities, and an oxide film that is formed on the base material and contains 25 to 97% of Fe and 3 to 75% of Cr. This heat resistant ferritic steel is excellent in photoselective absorptivity and oxidation resistance.

A method for treating an outer surface of a heat transfer fluid tube especially for a receiver of a solar thermal power plant, having the steps of providing the heat transfer fluid tube and treating the outer surface with a hydrogen plasma jet so that a porosity in the range of a nano-scale is created in a thin layer of that outer surface.

Methods, systems, and devices are disclosed for fabricating and implementing optically absorbing coatings. In one aspect, an optically selective coating includes a substrate formed of a solar energy absorbing material, and a nanostructure material formed over the substrate as a coating capable of absorbing solar energy in a selected spectrum and reflecting the solar energy in another selected spectrum. A concentrating solar power (CSP) system includes heat transfer fluids (HTFs); thermal energy storage system (TES); and solar receivers in communication with HTFs and including a light absorbing coating layer based on cobalt oxide nanoparticles.

A thin-film-coating/substrate two-layer thermal absorber/emitter structure is configured with controllable emission properties at ultra-high operating temperatures. The proposed two-layer thermal absorber/emitter structure is composed of a substrate made of a first material, and a thin-film layer/coating made of a second material and disposed on the substrate. The single thin-film layer or coating provides control and tuning of the emission properties of the overall two-layer thermal absorber/emitter structure. Both materials selected for the absorber/emitter structure possess high melt points to withstand extreme temperature variations. The two-layer thermal absorber/emitter structure reduces the complexity and cost of fabrication and manufacture and the likelihood of thermal failure.

A solar radiation absorber element for a thermal concentrating solar power plant is achieved by forming a selective coating on an outer surface of a substrate made from stainless steel, chosen from stainless steels presenting an aluminum content of more than 0.5% by weight. Formation of the selective coating includes a surface treatment step of the substrate, by polishing, and a heat treatment step of the substrate, in an oxidizing atmosphere, in a temperature range included between 550 C. and 650 C. The heat treatment in particular enables at least one intrinsically selective superficial thin layer to be formed on the outer surface of the substrate.

A solar-thermal conversion member includes a -FeSi.sub.2 phase material. The solar-thermal conversion member exhibits a high absorptance for visible light at wavelengths of several hundred nm and a low absorptance for infrared light at wavelengths of several thousand nm and, as a consequence, efficiently absorbs visible light at wavelengths of several hundred nm and converts the same into heat and exhibits little thermal radiation due to thermal emission at temperatures of several hundred C. The solar-thermal conversion member may therefore efficiently absorb sunlight, provide heat, and prevent thermal radiation due to thermal emission.