Solar thermal units and methods of operating solar thermal units for the conversion of solar insolation to thermal energy are provided. In some examples, solar thermal units have an inlet, and a split flow of heat absorbing fluid to either side of the solar thermal unit, along a first fluid flow path and a second fluid flow path. Optionally, one or more photovoltaic panels can be provided as part of the solar thermal unit, which may convert solar insolation to electric power that may be used by a system connected to the solar thermal unit.

Solar thermal units and methods of operating solar thermal units for the conversion of solar insolation to thermal energy are provided. In some examples, solar thermal units have an inlet, and a split flow of heat absorbing fluid to either side of the solar thermal unit, along a first fluid flow path and a second fluid flow path. Optionally, one or more photovoltaic panels can be provided as part of the solar thermal unit, which may convert solar insolation to electric power that may be used by a system connected to the solar thermal unit.

Solar thermal units and methods of operating solar thermal units for the conversion of solar insolation to thermal energy are provided. In some examples, solar thermal units have an inlet, and a split flow of heat absorbing fluid to either side of the solar thermal unit, along a first fluid flow path and a second fluid flow path. Optionally, one or more photovoltaic panels can be provided as part of the solar thermal unit, which may convert solar insolation to electric power that may be used by a system connected to the solar thermal unit.

Solar thermal units and methods of operating solar thermal units for the conversion of solar insolation to thermal energy are provided. In some examples, solar thermal units have an inlet, and a split flow of heat absorbing fluid to either side of the solar thermal unit, along a first fluid flow path and a second fluid flow path. Optionally, one or more photovoltaic panels can be provided as part of the solar thermal unit, which may convert solar insolation to electric power that may be used by a system connected to the solar thermal unit.

A solar collector arrangement comprises at least two solar collectors, each solar collector comprising at least one collector element with at least one flow channel for receiving heat transfer medium to be heated in the solar collector. The at least two solar collectors are arranged in parallel connection relative to each other and the heat transfer medium to be heated in the solar collectors and the heat transfer medium heated in the solar collectors are arranged to flow into the solar collectors and out of the solar collectors in turns one or some solar collectors of the solar collector arrangement at a time.

A solar thermal collector is provided. The collector comprises a housing defining an inlet, and an outlet for a heat transfer fluid, said housing comprising a window to allow sunlight to pass there through; a heat transfer core disposed within the interior of the housing said housing designed to be heated by exposure to said sunlight; and a heat absorbing component in proximity to the heat transfer core, said heat absorbing component designed to at least partially absorb heat losses from the heat transfer core; wherein a positioning the components within the housing defines at least one path for the heat transfer fluid for preheating of the heat transfer fluid prior to said heat transfer fluid passing through the heat transfer core.

A solar thermal absorber including a spectrally selective filter comprising a stack of dielectric layers and one or more semiconductor absorber layers. The dielectric layers are transparent to infrared radiation and have a refractive index contrast, and the semiconductor absorber layers have a band gap, such that the semiconductor absorber layers absorb at least a portion of the solar spectrum and the stack reflects infrared radiation.

An apparatus (10) and method for the co-production of high temperature thermal energy and electrical energy from solar irradiance includes a photovoltaic cell (30) laminated to a metal extrusion device (40) and a transparent channel (20) in front of the photovoltaic cell (30). The transparent channel (20) contains a heat transfer fluid that is seeded with metallic, semiconducting, and/or non-metallic nanoparticles and absorbs wavelengths of solar energy that are not utilized or underutilized by the photovoltaic cell (30).

An apparatus (10) and method for the co-production of high temperature thermal energy and electrical energy from solar irradiance includes a photovoltaic cell (30) laminated to a metal extrusion device (40) and a transparent channel (20) in front of the photovoltaic cell (30). The transparent channel (20) contains a heat transfer fluid that is seeded with metallic, semiconducting, and/or non-metallic nanoparticles and absorbs wavelengths of solar energy that are not utilized or underutilized by the photovoltaic cell (30).

The present invention recognizes that there exists a long felt and unfulfilled need for a photobioreactor for treatment of wastewater (Passive Aerobic Treatment Unit (PATU). As a non-limiting introduction to the breadth of the present invention, the present invention includes several general and useful aspects, including but not limited to: a) a device or system for the passive treatment of a preferably liquid wastewater stream using autotrophic, phototrophic, and heterotrophic microorganisms growing in a photobioreactor; and b) a method of treating wastewater using the devices of the present invention.