String voltage mismatch

What it is

The power lost because parallel strings on one inverter do not have the same voltage, as a fraction.

Typical values and how to get it

A common design range is 0.15 % to 0.5 %. If not given: 0: no string mismatch.

How it is applied

$$P_{\text{after}} = P_{\text{before}}\,(1 - f_{\text{str}})$$

where

Symbol	Meaning	Unit
$P_{\text{after}}$	the array DC power after this derate	W
$P_{\text{before}}$	the array DC power before it	W
$f_{\text{str}}$	this input as a fraction	—

API

dc_losses.string_mismatch_loss — sent as a fraction 0–1

Symbols follow the symbol registry.