Cleaning Schedule and Soiling Loss

Hello,
I am trying to model soiling losses as accurately as possible in SAM. From the documentation, it seems that SAM splits up the entered monthly soiling loss and assigns it to every hour of the month. This seems to be a reasonable approximation for a monthly cleaning schedule.
I currently have an experimentally determined soiling loss (%) of 0.35% per day. But in the case where panels are cleaned weekly (and so, the soiling loss would be on a weekly basis as opposed to monthly), is there a way to capture this in SAM? Or alternatively, is there a reasonable way to approximate this given the current way SAM inputs these numbers?

Thanks!

Hello,

As you correctly note, SAM provides inputs for a single soiling loss that applies to the incident irradiance every hour (or subhourly time step) of the year, or a set of 12 monthly losses that apply to the irradiance every hour by month.

You could use the shading loss inputs on the Shading and Snow input page to represent soiling losses, although the shading loss apply only to the beam component of the incident irradiance, while the shading loss applies to the beam and diffuse components. For shading losses, SAM provides several options for entering data: Hourly (or subhourly), month-by-hour, or solar azimuth-by-altitude.

Thanks,
Paul.

Thanks Paul, appreciate it!