Module quality loss

What this step does

The difference between the modules' real power and their nameplate, taken as a flat fraction of the array energy. A negative input, which describes modules that produce more than their nameplate, shows as a gain.

The math

$$E_{after} = E_{before} - L_q,\qquad L_q = f_q\,E_{before} \tag{1}$$

where

Symbol	Meaning	Unit
$E_{before}$	the running total of the loss diagram before this row	kWh/kWp
$E_{after}$	the running total after this row	kWh/kWp
$L_q$	the row as a loss; negative for a gain	kWh/kWp
$f_q$	the module quality loss input, a fraction; negative for a gain	—

Reading the number

Negative for a loss and positive for a gain. Modules with a positive power tolerance give a gain of about 0.4 to 0.8 %, on utility and rooftop systems alike. The row follows the input alone.

API

loss.quality

Symbols follow the symbol registry.