I did 2 simulation using PVsyst.
1. Trina 340Wp poly panels
2. Astronenergy 340Wp poly Half-cut panels
The results shows that the Globeff are different for both simulation.
I understand that the defination for Globeff : Effective Global, corr, for IAM and shading.
The incidence effect (the designated term is IAM, for "Incidence Angle Modifier") corresponds to the decrease of the irradiance really reaching the PV cells's surface, with respect to irradiance under normal incidence. This decrease is mainly due to reflexions on the glass cover, which increases with the incidence angle.
The transmission loss is a general phenomenon, due to the reflexion and transmission of the sun's ray at each material interface (air-glass, glass-EVA, EVA-cell), as well as some absorption in the glass. This arises for any incidence ray. For normal incidence, the reflexion is of the order of 5%, and is included in the measured STC performance. The IAM only concerns the angular dependency of this effect, i.e. it is normalized to the transmission at perpendicular incidence (0° incidence angle).
My question is,
1) Are the difference in Glob effective due to the fact that both technology are different? Trina using poly and Astronenergy using Half cut cells?
2) What are the formula used for calculation Earray and Egrid?