Abstract: 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.

Abstract: A heat receiver tube having first, second, and further partial heat receiver tube surfaces for absorbing and transferring solar energy to heat transfer fluid is presented. The first and further partial heat receiver tube surfaces are formed by solar absorptive coatings deposited on partial surfaces of core tube. The second partial heat receiver tube surface is formed by emission radiation inhibiting coating deposited on second core tube surface for inhibiting emissivity for infrared radiation. The further partial heat receiver tube surface is arranged in radiation window of second partial heat receiver tube surface such that direct sunlight impinges further partial heat receiver tube surface. The heat receiver tube is arranged in focal line of parabolic mirror of parabolic trough collector. The first partial heat receiver tube surface and sunlight reflecting surface is arranged face to face, second and further partial heat receiver tube surfaces are averted to reflecting surface.

Abstract: A solar thermal energy system (20) includes a plurality of modules (22), which are connected end-to-end to define an extended solar trough. Each module includes a frame, having an outer edge of circular profile and an inner edge of parabolic profile, having a focus at a geometrical center of the circular profile. The frame includes first and second end segments (42) at respective first and second ends of the module, and a pair of rigid torque tubes (44) connected longitudinally between the first and second end segments. A motorized drive (46) engages and rotates the outer edge of the frame about the geometrical center. Multiple mirror segments (40) are fitted to the inner edge of the frame. At least one heat transfer tube segment (24) is held stationary at the geometrical center of the frame.

Abstract: A solar receiver tube assembly is provided with at least one first solar receiver tube with a first selective absorptive coating; at least one second solar receiver tube with a second selective absorptive coating, wherein values of at least one optical characteristic of the first selective coating and the second selective coating differs from each other while an operating the solar receiver tube assembly. The optical characteristics are preferably ? and ?. The idea is to improve the effectiveness of the receiver tubes along the receiver assembly.

Abstract: A heat receiver tube having first, second, and further partial heat receiver tube surfaces for absorbing and transferring solar energy to heat transfer fluid is presented. The first and further partial heat receiver tube surfaces are formed by solar absorptive coatings deposited on partial surfaces of core tube. The second partial heat receiver tube surface is formed by emission radiation inhibiting coating deposited on second core tube surface for inhibiting emissivity for infrared radiation. The further partial heat receiver tube surface is arranged in radiation window of second partial heat receiver tube surface such that direct sunlight impinges further partial heat receiver tube surface. The heat receiver tube is arranged in focal line of parabolic mirror of parabolic trough collector. The first partial heat receiver tube surface and sunlight reflecting surface is arranged face to face, second and further partial heat receiver tube surfaces are averted to reflecting surface.

Abstract: 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.