Global Radiation - Deviation from standard spectrum

[PVEnergy]

What is a good standard of deviation from global radiation (AM1.5)? 

We've been debating and we have been using either 10% or 7.5% for any area, was curious if anyone has an opinion or could give some advice.

Cheers.

[hotline_oh]

Dear PVEnergy,

Thank you for your inquiry.

The spectral mismatch alters the module's efficiency curve, which was measured using a standard spectrum. We assume that an annual average correction factor of 1% can be expected in Central Europe.