[PVsyst Ageing Losses and LID]

In the PV Syst Help page, it is said this note about ageing:

"NB: The simulation for a given year takes the average loss calculated mid year. For example for the 10th year of operation, the ageing loss factor will be calculated over 9.5 years.

For the usual simulations of PVsyst (first year) we should indeed consider the degradation after 6 months"

I would like to know why it is calculated like this way.

 

I have the same question. Do you have a specific technical justification for this? is this because of data granularity?

thank you