Monthly table

Method

Each month's soiling fraction removes that share of every component of the light on the plane, after the shading steps.

The math

$$G_{soiled,i} = (1 - s_{m(i)})\,G_{shaded,i} \tag{1}$$

where

Symbol	Meaning	Unit
$G_{soiled,i}$	the light after soiling at timestep $i$	W/m²
$s_{m(i)}$	the soiling fraction of the month timestep $i$ falls in	—
$G_{shaded,i}$	the light after the shading steps	W/m²

References

1. Kimber, Mitchell, Nogradi & Wenger 2006, The effect of soiling on large grid-connected photovoltaic systems in California and the Southwest region of the United States, IEEE 4th World Conference on Photovoltaic Energy Conversion

API

site.use_soiling = true

Symbols follow the symbol registry.