This invention concerns a receiver unit (10) for a parabolic trough solar plant. The receiver unit (10) has a conduit (12) for conveying a heat transfer fluid (14) and a cover (16), which is located about the conduit (12) such that a vacuum is formed between the conduit and the cover. The conduit (12) is designed to absorb thermal radiation. The cover (16) has a first portion (26) defining a window (22) through which incoming solar radiation (24) passes into the vacuum and onto the conduit (12) and a second portion (28) carrying a reflective surface (20) so as to reflect thermal radiation back onto the conduit (12). The invention also concerns a method of reducing thermal radiation loss from a parabolic trough receiver.

This invention concerns a receiver unit (10) for a parabolic trough solar plant. The receiver unit (10) has a conduit (12) for conveying a heat transfer fluid (14) and a cover (16), which is located about the conduit (12) such that a vacuum is formed between the conduit and the cover. The conduit (12) is designed to absorb thermal radiation. The cover (16) has a first portion (26) defining a window (22) through which incoming solar radiation (24) passes into the vacuum and onto the conduit (12) and a second portion (28) carrying a reflective surface (20) so as to reflect thermal radiation back onto the conduit (12). The invention also concerns a method of reducing thermal radiation loss from a parabolic trough receiver.

An assembly including: a central enclosure including: an inner wall that is water-resistant and non-corrosive, an outer wall that is transparent, the inner and outer walls hermetically sealed together to form a watertight compartment defined between the inner and outer walls, an inlet port located on a lower portion of the central enclosure, an outlet port located on an upper portion of the central enclosure, and a solar collector member disposed inside the watertight compartment, the member being disposed between the inner and outer walls; an external glass pane spaced apart from the outer wall and defining an external insulation layer of gas between the external glass pane and the outer wall; and an internal partition spaced apart from the inner wall and defining an internal insulation layer of gas between the internal partition and the inner wall.

An assembly including: a central enclosure including: an inner wall that is water-resistant and non-corrosive, an outer wall that is transparent, the inner and outer walls hermetically sealed together to form a watertight compartment defined between the inner and outer walls, an inlet port located on a lower portion of the central enclosure, an outlet port located on an upper portion of the central enclosure, and a solar collector member disposed inside the watertight compartment, the member being disposed between the inner and outer walls; an external glass pane spaced apart from the outer wall and defining an external insulation layer of gas between the external glass pane and the outer wall; and an internal partition spaced apart from the inner wall and defining an internal insulation layer of gas between the internal partition and the inner wall.

Articles, systems, and methods in which electromagnetic energy is converted to heat (e.g., for the purpose of inducing or inhibiting phase change of a material disposed over a surface) are generally described.

Articles, systems, and methods in which electromagnetic energy is converted to heat (e.g., for the purpose of inducing or inhibiting phase change of a material disposed over a surface) are generally described.

A design for a micro-lens (i.e., a lens on the scale of micrometers) incorporates existing nanofabrication techniques and can be incorporated into High Concentrating Photovoltaic (HCPV), solar thermal collectors, and traditional flat PV systems. Using the theory of wave optics, the design is able to achieve a high numerical aperture, i.e., it can receive light over a wider range of angles. The design also reduces the distance the focal point shifts as the light source shifts; this eliminates the need for a tracking system in CPV and PV applications. Reducing the lens size also facilitates smaller, lightweight CPV systems, which makes CPV attractive for additional applications. Finally, these concentrators reduce the exchanging area of a typical flat solar thermal system where heat is received, which improves the overall system's efficiency and allows its use also during rigid winter time.

A design for a micro-lens (i.e., a lens on the scale of micrometers) incorporates existing nanofabrication techniques and can be incorporated into High Concentrating Photovoltaic (HCPV), solar thermal collectors, and traditional flat PV systems. Using the theory of wave optics, the design is able to achieve a high numerical aperture, i.e., it can receive light over a wider range of angles. The design also reduces the distance the focal point shifts as the light source shifts; this eliminates the need for a tracking system in CPV and PV applications. Reducing the lens size also facilitates smaller, lightweight CPV systems, which makes CPV attractive for additional applications. Finally, these concentrators reduce the exchanging area of a typical flat solar thermal system where heat is received, which improves the overall system's efficiency and allows its use also during rigid winter time.

This invention concerns a receiver unit (10) for a parabolic trough solar plant. The receiver unit (10) has a conduit (12) for conveying a heat transfer fluid (14) and a cover (16), which is located about the conduit (12) such that a vacuum is formed between the conduit and the cover. The conduit (12) is designed to absorb thermal radiation. The cover (16) has a first portion (26) defining a window (22) through which incoming solar radiation (24) passes into the vacuum and onto the conduit (12) and a second portion (28) carrying a reflective surface (20) so as to reflect thermal radiation back onto the conduit (12). The invention also concerns a method of reducing thermal radiation loss from a parabolic trough receiver.

This invention concerns a receiver unit (10) for a parabolic trough solar plant. The receiver unit (10) has a conduit (12) for conveying a heat transfer fluid (14) and a cover (16), which is located about the conduit (12) such that a vacuum is formed between the conduit and the cover. The conduit (12) is designed to absorb thermal radiation. The cover (16) has a first portion (26) defining a window (22) through which incoming solar radiation (24) passes into the vacuum and onto the conduit (12) and a second portion (28) carrying a reflective surface (20) so as to reflect thermal radiation back onto the conduit (12). The invention also concerns a method of reducing thermal radiation loss from a parabolic trough receiver.