A solar heat collector tube in which at least an infrared reflective layer, a sunlight-heat conversion layer and an anti-reflection layer are provided on the outer surface of a tube through the interior of which a heat medium can flow, wherein the infrared reflective layer in the solar heat collector tube is an Ag layer having Nb dispersed therein, the content of Nb being 0.1 at % to 31.8 at %.

A solar heat collector tube in which at least an infrared reflective layer, a sunlight-heat conversion layer and an anti-reflection layer are provided on the outer surface of a tube through the interior of which a heat medium can flow, wherein the infrared reflective layer in the solar heat collector tube is an Ag layer having Nb dispersed therein, the content of Nb being 0.1 at % to 31.8 at %.

A system for energy conversion including photoluminescent (PL) material for absorbing solar radiation and emitting PL radiation, a solar concentrator for concentrating solar radiation on the PL material, photovoltaic (PV) material configured to absorb the PL radiation, and a chamber for containing the PL material and Heat Transfer Fluid (HTF), and further including the system configured to pipe the HTF from the chamber to a system for conversion of HTF heat to energy. Related apparatus and methods are also described.

A system for energy conversion including photoluminescent (PL) material for absorbing solar radiation and emitting PL radiation, a solar concentrator for concentrating solar radiation on the PL material, photovoltaic (PV) material configured to absorb the PL radiation, and a chamber for containing the PL material and Heat Transfer Fluid (HTF), and further including the system configured to pipe the HTF from the chamber to a system for conversion of HTF heat to energy. Related apparatus and methods are also described.

Solar thermal devices are formed from a block of wood, where the natural cell lumens of the wood form an interconnected network that transports fluid or material therein. The block of wood can be modified to increase absorption of solar radiation. Combining the solar absorption effects with the natural transport network can be used for various applications. In some embodiments, heating of the modified block of wood by insolation can be used to evaporate a fluid, for example, evaporating water for extraction, distillation, or desalination. In other embodiments, heating of the modified block of wood by insolation can be used to change transport properties of a material to allow it to be transported in the interconnected network, for example, heating crude oil to adsorb the oil within the block of wood.

Solar thermal devices are formed from a block of wood, where the natural cell lumens of the wood form an interconnected network that transports fluid or material therein. The block of wood can be modified to increase absorption of solar radiation. Combining the solar absorption effects with the natural transport network can be used for various applications. In some embodiments, heating of the modified block of wood by insolation can be used to evaporate a fluid, for example, evaporating water for extraction, distillation, or desalination. In other embodiments, heating of the modified block of wood by insolation can be used to change transport properties of a material to allow it to be transported in the interconnected network, for example, heating crude oil to adsorb the oil within the block of wood.

A solar reactor useful in reaction processes, more particularly, useful in endothermic reaction processes, such as a catalyzed process or an adsorption-desorption process. The reactor comprises a reaction pathway defined by an exterior wall and an interior wall, the exterior wall comprising a solar radiation receiver capable of converting solar radiation into heat and transmitting the heat to the reaction pathway. The reaction pathway has disposed therein, in alternating fashion, a plurality of reactive elements comprised of a catalyst or a sorbent and a plurality of heat transfer elements.

The receiver according to the invention is provided with the heating area for heating a heat-transporting medium, which has an optical opening for sunlight, an absorber absorbing the sunlight arranged within the path of the incidental sunlight and with a transport arrangement for the transport of the medium through the heating area, wherein the absorber is designed as a blackbody radiation arrangement with reduced convection and the transport arrangement for the transport of a gas is designed as a heat-transporting medium. By means of this, the receiver can be designed in a simpler and more reliable manner.

The receiver according to the invention is provided with the heating area for heating a heat-transporting medium, which has an optical opening for sunlight, an absorber absorbing the sunlight arranged within the path of the incidental sunlight and with a transport arrangement for the transport of the medium through the heating area, wherein the absorber is designed as a blackbody radiation arrangement with reduced convection and the transport arrangement for the transport of a gas is designed as a heat-transporting medium. By means of this, the receiver can be designed in a simpler and more reliable manner.

The present invention provides a solar absorber incorporated bilayer foam solar evaporator for seawater and wastewater purification including a plurality of solar absorbers partially incorporated into a porous polymer framework and partially forming a thermal insulation layer proximal to solar irradiation. In particular, low-cost commercially available B.sub.4C powders are embedded into a porous polymer foam in a one-pot method to form a scaffold of boron carbide bilayer foam (BCBF) with good hydrophilic wettability, heat-shielding, and solar-thermal conversion. The boron carbide bilayer foam (BCBF) of the present invention enables a high cost-performance seawater desalination and wastewater purification at a high evaporation rate of 2.8 kg/m.sup.2/h with 93% solar evaporation efficiency under 1 sun illumination (or 1 kW/m.sup.2). The present invention thereby provides an excellent and cost-effective solar evaporator tool for industrial-level water purification. Following the present method to prepare the BCBF solar evaporator, the fabrication cost can be as low as 3.6 $/m.sup.2.