About the importance of correct albedo determination in modeling the diffuse irradiation on tilted surfaces

✍ Scribed by R. Festa; C.F. Ratto

• Publisher: Elsevier Science
• Year: 1989
• Weight: 695 KB
• Volume: 6
• Category: Article
• ISSN: 0741-983X
• DOI: 10.1016/0741-983x(89)90021-0

✦ Synopsis

Almtraet--The aim of this work is to test the importance of a correct estimation of the radiation reflected by the ground and received by a tilted surface, i.e. of the albedo coefficient, on the evaluation of the diffuse radiation on the same tilted surface. The sensibility of diffuse radiation models to the albedo coefficient value is also tested. NOMENCLATURE B hourly beam irradiation D hourly diffuse irradiation E hourly extraterrestrial irradiation G hourly global irradiation c~ surface-solar azimuth /3 slope of inclined surface with respect to the horizontal xt zero when the surface does not face the sun ; otherwise ratio Bt/Bh = cos Ot/cos Oh p albedo coefficient average albedo coefficient relative to a set of data ~, solar azimuth 0, angle between the beam radiation and the normal to the inclined surface Oh solar zenith angle, i.e. the angle between the beam radiation and the vertical

Subscripts

e relative to a surface facing east h relative to a horizontal surface n relative to a surface facing north t relative to a tilted surface s relative to a surface facing south v relative to a vertical surface w relative to a surface facing west