Degradation aging in thin-film PV modules
The term “degradation aging” plays a part when you are using thin-film PV modules. In the case of these modules, the material must first stabilize after production.
Therefore, immediately after production, they have high electrical data characteristics (power, voltage, and current) which are up to 10-15% above the specifications in the relevant datasheet.
The modules stabilize during the first operating phase. The characteristics then approach the key figures specified on the datasheet. This is called degradation aging.
When designing a PV plant, the voltage degradation is of primary importance since the inverter can be damaged by an excessively high input voltage. Therefore, the layout with the maximum expected open-circuit voltage should be used.
Sunny Design uses these extreme values for the plant configuration, provided they are specified by the module manufacturer:
- Sunny Design calculates the maximum expected open-circuit voltage of the PV module at low cell temperatures with higher characteristics (default settings)
- Sunny Design calculates the minimum anticipated MPP voltage of the PV modules with the datasheet specifications (stabilized value after degradation aging)
Next, the program checks whether the calculated voltage values are within the permissible input voltage range of the inverter.
If you have any further questions about this please contact the module manufacturer directly.