PV Temperature Derating Calculator

Specifications are provided at 25C operating temp, but actual temps are higher in operation. Derating is about 0.4%/C - or 8% at the typical 45 degree workign temp.

https://www.solarquotes.com.au/blog/solar-panels-temperature/#:~:text=What%20Is%20NOCT%3F,800%20watts%20per%20square%20meter.

Derating calculator:

https://www.digivation.com.au/solar/tempderate.php