Electrical losses
After calculating the power delivered by the module, the losses on the direct current side are applied.
Aggregated losses
Typical values for a well-built installation, editable in Advanced settings:
| Loss | Default | What it represents |
|---|---|---|
| Mismatch | 2,0 % | Manufacturing differences between cells and modules |
| DC cabling | 1,0 % | Resistance of the copper in direct current |
| Connections | 0,5 % | MC4 connectors and joints |
| Availability | 1,0 % | Maintenance, faults, grid outages |
They are applied as multiplicative factors on the DC power.
Calculated cabling
If you enable Cabling and protections, the DC cable loss is no longer the fixed 1 % and is calculated hour by hour as I²·R with the chosen cross-section of each string; the AC side is calculated the same way. See Cabling and protections.
With optimizers
The mismatch loss disappears (each module works at its MPP) and the optimizer efficiency loss appears (1 − efficiency, 1 % by default).
Mismatch from shading in parallel
If the strings of the same MPPT receive different shading, there is an additional loss because the MPPT imposes a single voltage. It is calculated with the real I-V curves (see Objects and shading).
Where to see them
In the waterfall they appear separately: «Module mismatch», «DC cabling (ohmic losses)», «Connections», «System availability» and, where applicable, the mismatch between parallel strings due to shading.