Many panels have published NOTC.
This test is @ 80% or 800 watts per square meter vs 1000.
20C air blowing on the panel @ 20C.
45C temps in these conditions! with a breeze and space behind the panel for air flow.
"Both conductive and convective heat transfer are significantly affected by the mounting conditions of the PV module. A rear surface which cannot exchange heat with the ambient (i.e., a covered rear surface such as that directly mounted on a roof with no air gap), will effectively have an infinite rear thermal resistance. Similarly, convection in these conditions is limited to the convection from the front of the module. Roof integrated mounting thus causes higher operating temperature, often increasing the temperature of the modules by 10°C."
https://www.pveducation.org/pvcdrom/modules-and-arrays/nominal-operating-cell-temperature
