Same thought on Meteonorm, i've always thought of it as the most reliable, came here to see what people thought of PVGIS 5.2
Ran a quick test in Perth, Meteonorm shows 100% Sat?
Source Global Diffuse
Meteonorm 8.0 2052.6 568.0
NASA-SSE 1836.3 565.2
PVGIS 5.2 1921.6 612.8
Gonna have a significant effect on results, so like to hear the consensus on what is more accurate?