Moataz Yassin

So does this voltage calculated based on the Temperature only or does it consider the irradiance at this temperature also ? because at the low temperature the irradiance is very low so although the voltage increase due to low temp there is an opposite factor that limit this increase which is the irradiance and this data is from the TMY file and regarding the lowest temperature do i have to insert it in the project setting or the data can be used automatically from the TMY file i inserted ?

We are facing a problem regarding the number of modules in series in a project in the gulf area. all the manual calculations indicates that we can use from 29 to 30 modules in series of power of 570Wp and Voc 51.07 after considering the lowest temperature on site and the irradiance at this temperature the voltage became suitable to use 29 or 30 modules but the PVSYST indicates maximum of 28 so what considerations does the software uses as we extracted the Tarray and the Irradiance and the string operating voltage and all are within the limits so do anyone has a reason why PVSYST use less modules ?