Global incident below threshold

What this step does

Timesteps whose plane irradiance is below the low-light threshold, 7 W/m² by default, are set to zero. This removes the faint light of dawn and dusk that no inverter would convert.

The math

1. Running total
2. Loss at a timestep

$$E_{after} = E_{before} - E_{row},\qquad E_{row} = \frac{\Delta t}{1000}\sum_i L_i \tag{1}$$ $$L_i = \begin{cases} G_{trp,i} & G_{trp,i} < G_{thr} \\ 0 & \text{otherwise} \end{cases} \tag{2}$$

where

Symbol	Meaning	Unit
$E_{before}$	the running total of the loss diagram before this row	kWh/m²
$E_{after}$	the running total after this row	kWh/m²
$E_{row}$	the row taken as a loss	kWh/m²
$\Delta t$	the length of one timestep	hours
$L_i$	the irradiance lost at timestep $i$	W/m²
$G_{trp,i}$	the plane irradiance before the threshold	W/m²
$G_{thr}$	the low-light threshold	W/m²

Reading the number

A loss, negative: a fraction of a kWh/m² per year on utility and rooftop systems alike. A higher threshold makes it larger. The row is absent when the threshold is switched off (Model tab) or set to 0 W/m² (Physics tab).

API

loss.threshold

Symbols follow the symbol registry.