Defining albedo based on air temperature

[george]

Hello,

I want to conduct an analysis on Photovoltaic array.

I need a weather file for particular location. It can not be found in the PVsyst Meteo database.

But Meteonorm has it. The problem is that this Meteonorm weather file does not contain data about snow depth nor albedos.

I was wondering if I could approximate this by somehow defining the albedo to be 0.6 (ground covered with wet snow) in cases when air temperature is bellow some value.

Which value would that be? Certainly not 0°C but probably something bellow 0°C.

RETscreen advices using 0.7 albedo for -5°C temperatures, and interpolated albedo values from 0.7 to 0.2 for air temperatures between -5°C and 0°C (example: -4°C - 0.6, -3°C - 0.5, -2°C - 0.4, -1°C - 0.3, 0°C - 0.2, 1°C - 0.2...).

Do you think this is correct?

I can see from tutorials that you recommend defining a 0.8 albedo for just a few months (when snow is expected). I have no problem with using the 0.8 albedo value, but can I use it when air temperature is bellow some value, instead of just defining it for certain months?

Thank you for the reply.