Abstract: A heat-transfer concentrate comprising a storage-stable dispersion of a heat-storage medium and gallium adsorbed onto a solid having either a particle diameter of 1 to 3 um or a pore diameter of 0.2 to 0.6 nm, or both, is provided. The invention also provides a method of manufacture for the concentrate, and a heat-transfer mixture comprising the heat-transfer concentrate and another heat-storage medium. The invention further provides methods of using the heat-transfer mixture to store and convey heat in reactors with heat exchangers, as well as methods of use in heat pumps and as a thermochemical energy-storage medium.

Abstract: The present invention relates to a device for obtaining heat and/or electrical energy from sunlight with at least one solar collector (2) having an absorber (4) and an energy concentrator (6) surrounding the absorber over its length and at least regions of its periphery and optically concentrating the sunlight on the absorber (4). The energy concentrator (6) has a prism arrangement (12) of transparent material at least at its peripheral region which will be illuminated by the sunlight in accordance with the sun's daily movements, with a plurality of axial adjacent prisms (14) running parallel to the absorber (4) and distributed around the periphery. All the prisms (14) are equal sided in cross section and their apexes (18) are directed towards the absorber (4).