Abstract: A solar trough includes a light receiver for transporting a fluid to be heated by the solar trough, at least one rail partially or fully disposed in a trench, a parabolic light collector slidably mounted on the at least one rail, and a drive unit for rotating the parabolic light collector within the trench. Further, a solar trough system made up of a plurality of the solar troughs.

Abstract: A matched glass-to-metal connecting device for use in a vacuum tube collector for a solar energy collecting apparatus is made of a glass envelope and a metal sleeve directly bonded to the glass envelope. The glass envelope is made of a glass having a composition, in percent by weight on the basis of oxide content, consisting essentially of B2O3, 19; Al2O3, 8; Na2O, 2; K2O2, 3; BaO, 3; LiF, 1; and balance of SiO2 and the metal sleeve consists of metal material number 1.3981 of DIN 17745. The glass envelope has a thermal expansion coefficient that deviates from the metal part's thermal expansion coefficient by no more than 4% in the temperature range from 25° C. to 350° C.