Monthly global irradiation on tilted planes : a simple correlation method and its validation

Bernard Bourges (1, 2)

1 consultant
2 CEP - Centre Énergétique et Procédés

This paper presents a simple correlation for the computation of monthly global solar irradiation on tilted surfaces, facing due south. The conversion factor, R, from the horizontal plane to the tilted plane, is considered: it has been established from the Solar Radiation European Atlas data (computed by Pr. Page's algorithm). R is linearly correlated to the monthly clearness index, Kt. The correlation slope depends on the month, the latitude and the tilt angle. This set of correlations fits the European Atlas Data within 2% in summer and 5% in winter (tilt ang. <60deg), within 5 to 10% for South-vertical surfaces. Validation results with respect to measured data from 7 locations are also presented. In some cases, there is a slight systematic underestimation by a few percent (Trappes, Carpentras, Albany); but generally the results seem to be consistent with the correlation scattering (Geneva, Ispra, Bracknell, Valentia).

Domaines: Sciences de l'ingénieur [physics]; Thermique [physics.class-ph]; Thermique [physics.class-ph]; Océan, Atmosphère

Bernard Bourges. Monthly global irradiation on tilted planes : a simple correlation method and its validation. BLOSS, W.H. and PFISTERER, F. Advances In Solar Energy Technology, Pergamon, pp.3811 - 3815, 1988, 978-0-08-034315-0. ⟨10.1016/B978-0-08-034315-0.50703-5⟩. ⟨hal-00949142⟩