Analyzing Temperature Variations and PV Output in PVsyst

[arash509]

Hello,

 

I have encountered a discrepancy regarding calculations in PVsyst software related to the impact of temperature variations on PV panel performance. It is commonly understood that when two PV panels have the same average surface temperature, the panel with a uniform temperature distribution should theoretically produce more electricity compared to a panel with variable temperature across its surface. However, when applying the formulas from the tutorial, my calculations suggest that both panels yield the same level of electricity production, which I believe is incorrect.

To illustrate with a simplified example, let's consider two photovoltaic-thermal (PVT) systems, each comprising only two PV cells:

 

• In PVT1, the cells have temperatures of 20°C and 40°C.
• In PVT2, both cells are at a uniform temperature of 30°C.

 

Despite the average surface temperature being the same for both panels, should there not be a difference in their electrical outputs due to the uniformity of temperature in PVT2 versus the temperature variation in PVT1?

Could you please help clarify this discrepancy?

question.pdf