A solar water-heating panel is provided, comprising a plurality of risers configured for utilizing solar radiation impinging thereon to heat a fluid therein. Each riser comprises a riser wall defining a fluid path for flow therethrough of the fluid. The panel further comprises one or more headers for facilitating delivery of the fluid between the panel and an external source of the fluid. The risers are parallely-arranged and separate from one another, and each comprises a longitudinal fin projecting sidewardly therefrom toward, and contacting, an adjacent riser.

The present invention is a solar concentrator composed of a generally V-shaped trough of reflective Fresnel steps. The Fresnel reflective steps concentrate the sunlight entering the mouth of the V-shaped trough and parallel to its central axis into a central focal area. By disposing a solar energy receiving element at the central focal area of sunlight concentration a preferred embodiment as a concentrating solar energy collector is realized. Various types of solar energy receiving structures are shown that serve to convert the concentrated sunlight into other forms of useful energy to realize the preferred embodiment as a concentrating solar energy collector.

A solar heat collector includes a plurality of heat collecting tubes connected in series. The heat collecting tubes each include: a heating-medium circulating tube through which a heating medium circulates; a glass tube that covers an outer peripheral surface of the heating-medium circulating tube and forms an annular space between the glass tube and the heating-medium circulating tube; and a getter member that adsorbs a gas that exists within the annular space. The heat collecting tube on a downstream side of the heating medium includes a larger number of the getter members than the heat collecting tube on an upstream side of the heating medium.

An arrangement for producing hot water from solar energy, the arrangement comprising: an elongate solar collector device extending along a longitudinal direction (X) from a first end to an opposite second end, the elongate solar collector device consisting of an elongate profile having walls that in between them define elongate cavities extending from the first end to the second end, the elongate solar collector device having at least one first opening for receiving water into the elongate cavities, and at least one second opening for tapping off water, arranged at a middle part of the elongate solar collector device; and at least one valve adapted to be arranged in a respective one of the at least one second opening, the valve being openable and closable in order to be able to tap off any water housed in the cavities.

A solar receiver for converting solar radiation into thermal energy. The solar receiver includes a heat-absorbing solid body, a fluid system to provide a flow of working fluid proximate to the heat-absorbing solid body, and a movement device to move the heat-absorbing solid body such that one or more surfaces of the heat-absorbing solid body are periodically exposed to incident solar radiation. The incident solar radiation heats a portion of the heat-absorbing solid body which in turn heats the working fluid. The at least a portion of the heat-absorbing solid body is configured to promote absorption of incident solar radiation, promote transfer of heat from the at least a portion of the heat-absorbing solid body to the working fluid, promote cooling of the at least a portion of the heat-absorbing solid body, or promote any combination thereof

A solar collector adapted to absorb thermal heating from the sun, wherein said solar collector comprises hollow sections adapted to house a medium. The solar collector is a self-supporting composite solar collector produced from a composite material constituted of at least a first and second material, wherein said first and second materials have equal or substantially equal coefficients of elasticity.

A thermophotovoltaic panel, including a first surface for receiving solar radiation, photovoltaic cells connected to said first receiving surface, a heat exchanger connected to said photovoltaic cells, and a second surface, opposite to the first, for supporting the panel, said heat exchanger being positioned between said first receiving surface and said second supporting surface, wherein said photovoltaic cells and said exchanger are embedded in at least one resin, preferably cold-polymerised epoxy resin, to constitute a body including said first receiving surface and said second supporting surface, wherein at least one layer of resin at said first receiving surface is constituted of substantially transparent resin.

A solar thermal system is provided. The system comprises at least one solar thermal collector for heating a heat transfer fluid (HTF); and at least one conduit for transporting the HTF into and out of the at least one solar thermal collector; wherein said at least one conduit is of a foam or plastics material.

A solar thermal system is provided. The system comprises at least one solar thermal collector for heating a heat transfer fluid (HTF); and at least one conduit for transporting the HTF into and out of the at least one solar thermal collector; wherein said at least one conduit is of a foam or plastics material.

A heat collector includes a body including a hollow portion extending from a first end to a second end of the body and being a metal-extruded body having a light-receiving surface to receive sunlight, a pair of lids adjacent to the first end and the second end and covering the hollow portion, an inlet located in one of the pair of lids to allow a heating medium to enter the hollow portion, and an outlet located in one of the pair of lids to allow the heating medium to exit the hollow portion.