Pr different in report and hourly data file

[IgLoo]

Hi

I generated report and hourly data file.

When I'm calculating monthly avg PR from hourly data file it is different from monthly value in report. 

I excluded hours without sun, and still there is difference 

[IgLoo]

[Michele Oliosi]

Can you explain your calculation for the monthly average PR ?

[IgLoo]

Hi 

I'm just taking hourly data for PR ratio of the specific month and using "average" formula 

[Michele Oliosi]

Ok then that is likely the reason. The PR is basically a ratio between yield and incident irradiance.
These values are different at every hour. Now, you should remember that the ratio of averages is not the average of the ratios.

The correct way would be to sum the yield (E_Grid) and average the global incident irradiance (GlobInc) separately and then recalculate the PR based on the two resulting values.

[IgLoo]

thx

Will try that