Newer chemistries are more linear in low light, and bifacial modules perform better in poor weather. Additionally a module without bypass diodes or one which is

Newer chemistries are more linear in low light, and bifacial modules perform better in poor weather. Additionally a module without bypass diodes or one which is not strung for varying voltages will effectively produce no power under uneven shade. Vertical bifacial modules produce significantly less energy overall, but more during morning/evening and during snow or cloudy conditions. This latter fact combined with the much lower module costs mean that -- in practical terms -- they perform vastly better in cloudy conditions.