Output Variance

[petet]

Can anyone suggest why two adjacent identical PV installations should differ by almost 15% in output?

just for clarity, same commissioning date, slope, pitch, azimuth, equipment etc

These are on neighbouring new houses, semi-detached, same roof. Built at same time.

Should we expect that much variation in panel efficiency??

 

[NozSpark]

Is there any shading?

 

[binky]

inverters the same? TV aerial and bird droppings? dodgy connection?

 

[steptoe]

someone missed a panel when they were connecting up?

different panel ratings? ie, 220w Vs 250w  thatd get you a 15% figure nearly