NOVELTY - The glass body comprises a surface, where an infrared light reflective coating (12) is attached to the glass body surface and the infrared light reflective coating comprises a graphene material film. The glass body is a glass tube with a glass tube wall (10). An inner surface of the glass tube wall comprises the glass body surface. The infrared light reflective coating further comprises a nanomaterial consisting of nanoparticles, nanorods and nanowires, and a transmission for solar radiation with a wavelength below 1200 nm, which is 0.5-0.99, preferably 0.8-0.95.    USE - The glass body is useful in a heat receiver tube of a parabolic trough collector for absorbing solar energy and for transferring absorbed solar energy to a heat transfer fluid (all claimed), where the parabolic trough collector is useful in a solar power plant for converting solar energy into electrical energy.    ADVANTAGE - The glass body with transparency of 90% and infrared reflection of 80% can effectively prevent the overall thermal loss and energy loss of the heat receiver tube.    DETAILED DESCRIPTION - The glass body comprises a surface, where an infrared light reflective coating (12) is attached to the glass body surface and the infrared light reflective coating comprises a graphene material film. The glass body is a glass tube with a glass tube wall (10). An inner surface of the glass tube wall comprises the glass body surface. The infrared light reflective coating further comprises a nanomaterial consisting of nanoparticles, nanorods and nanowires, and a transmission for solar radiation with a wavelength below 1200 nm, which is 0.5-0.99, preferably 0.8-0.95. An intermediate layer (14) with intermediate material is arranged between the glass body surface and the infrared light reflective coating. The graphene material comprises on dopant. INDEPENDENT CLAIMS are included for:    (1) a heat receiver tube;    (2) a parabolic trough collector; and    (3) a method for manufacturing a glass body.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic cross sectional view of a glass tube.    Glass tube wall (10)    Inner surface of glass tube (11)    Infrared light reflective coating (12)    Intermediate layer (14)    Encapsulation. (20)