If a Panel Is Rated 430 W, How Many Watts and Kilowatt-Hours Does It Actually Deliver?
Summary
The 430 W figure is output under a lab condition of 1,000 watts of sunlight per square meter with the cells at 25°C. On the Qcells Q.TRON BLK M-G2+ datasheet, the same 430 W module is rated at 325.8 W under normal operating conditions (NMOT: 800 W/m² and a module temperature of 43°C). Modeled for New York, one of these panels makes about 555 kWh a year, which averages roughly 2.0 kWh a day in July and 0.9 kWh a day in December.
Nameplate watts versus operating watts
A watt is a rate at one instant; a kilowatt-hour is that rate multiplied by time. The number on the label comes from Standard Test Conditions.
| Condition | 430 W class output | Voltage at max power | Current at max power |
|---|---|---|---|
| STC, 1,000 W/m², 25°C | 430 W | 32.94 V | 13.05 A |
| NMOT, 800 W/m², 43°C | 325.8 W | 31.72 V | 10.27 A |
The drop to about 76% has two parts. Sunlight is 80% of the STC level, and the module runs 18°C hotter, which at the datasheet's power temperature coefficient of −0.29% per °C costs about another 5%. Multiplying 0.8 by 0.948 gives the same 76%. A summer roof where the cells sit 20°C above 25°C would lose roughly 6% even in full 1,000 W/m² sun.
Kilowatt-hours by month
NLR's PVWatts, set to New York with a south-facing 20° roof and 14% losses, models 1,291 kWh a year per kW. Scaled to one 430 W panel:
| Month | Per panel, month | Daily average |
|---|---|---|
| January | about 34 kWh | about 1.1 kWh |
| July | about 61 kWh | about 2.0 kWh |
| December | about 27 kWh | about 0.9 kWh |
| Year | about 555 kWh | about 1.5 kWh |
The model's capacity factor, first-year output divided by what the nameplate would produce running flat out all year, is 14.7%.
Sources
- Qcells — Q.TRON BLK M-G2+ series datasheet (Rev02, 2026-04)
- NLR — PVWatts V8 API (New York, 1 kW, tilt 20°, azimuth 180°, losses 14%; run 2026-09-23)
- National Laboratory of the Rockies — PVWatts Calculator
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