Definition
NOCT (Nominal Operating Cell Temperature) is a PV module rating measured at 800 W/m² irradiance, 20°C ambient temperature, 1 m/s wind speed, open-rack mounting. Typical NOCT 42–48°C. Used to predict realistic operating cell temperatures.
NOCT Conditions
| Parameter | Value |
|---|---|
| Irradiance | 800 W/m² |
| Ambient temperature | 20°C |
| Wind speed | 1 m/s |
| Mounting | Open-rack |
Cell Temperature Estimation
T_cell = T_ambient + (NOCT − 20) × (G / 800)Where G = current irradiance.
Key Takeaways
- NOCT = module rating at 800 W/m², 20°C ambient, 1 m/s wind, open-rack.
- Typical 42–48°C; lower for HJT.
- Better predictor of real operating cell temperature than STC.
- Datasheet typically reports both STC and NOCT power.
- Energy modeling tools use NOCT for thermal calculations.
Frequently Asked Questions
4 commonly searched questions about NOCT (Nominal Operating Cell Temperature).
What is NOCT?
Nominal Operating Cell Temperature — a more realistic module rating condition than STC. Conditions: 800 W/m², 20°C ambient, 1 m/s wind, open-rack mounting.
Typical NOCT?
42–48°C for typical c-Si modules. Lower for HJT (cooler-running). Higher for high-power modules with denser cells.
Why does NOCT matter?
Used to estimate operating cell temperature: T_cell = T_ambient + (NOCT − 20) × (irradiance/800). More accurate than STC for energy modeling.
Where is NOCT on the datasheet?
Module datasheets typically list NOCT-rated power, voltage, and current alongside STC values.
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