STC reference power

Method

The AC loss fractions are stated at the STC reference power of the system. With the STC reference power left at 0 on the Losses tab, it is the DC nameplate reduced by the module and string mismatch derates (1). The run reports the value it used.

The math

$$P_{ref,sys} = P_{nom,dc}\,(1 - m_{mod})(1 - m_{str}) \tag{1}$$

where

Symbol	Meaning	Unit
$P_{ref,sys}$	the STC reference power of the system	W
$P_{nom,dc}$	the DC nameplate of the system	W
$m_{mod}$	the module mismatch fraction	—
$m_{str}$	the string mismatch fraction	—

Note

An entered value replaces the derived one. To reproduce the fractions of a report that prints its own reference power, enter that value.

References

1. PVsyst 8 help, AC ohmic losses: reference power
2. Analysis of PVsyst 8.1.5 outputs shows this convention in its results.

API

ac_losses.power_reference = pnompv_ac_stc

Symbols follow the symbol registry.