Solar to kWh Conversion Calculator
Convert solar panel output to kilowatt-hours based on panel specifications and environmental conditions. This helps you understand your solar system's energy production.
Typical Solar Panel Specifications
| Panel Type | Typical Wattage | Efficiency Range | Temperature Coefficient |
|---|---|---|---|
| Monocrystalline | 300-400W | 15-20% | -0.3%/°C |
| Polycrystalline | 250-350W | 13-16% | -0.4%/°C |
| Thin-film | 100-200W | 10-13% | -0.25%/°C |
Watts and kilowatt-hours are different questions
A watt is a rate; a kilowatt-hour is a quantity. A 400 W panel does not produce 400 W all day — it produces that only at full irradiance, and the daily energy figure is what the array delivers across the whole arc of the sun. Converting between the two is where peak sun hours come in, and it is the step most back-of-envelope estimates skip.
Why the conversion needs a loss factor
Between the cell and the meter sit inverter conversion, wiring resistance, module mismatch, soiling and the temperature coefficient of the panels themselves. Together they typically remove a fifth to a quarter of the theoretical figure, which is why an array sized on the raw calculation reliably disappoints.
Reading your own bill
The most reliable input is your own consumption in kilowatt-hours, taken from an annual bill and divided by 365. Appliance-by-appliance addition is useful for new builds and for finding waste, but for sizing an array against real use, the meter has already done the work.
Factors Affecting Solar Output:
- Sunlight intensity and duration
- Panel orientation and tilt angle
- Temperature effects
- Shading and obstructions
- System losses and efficiency
- Panel degradation over time
- Dust and dirt accumulation
Optimization Tips:
- Keep panels clean and well-maintained
- Optimize panel tilt angle for your location
- Minimize shading and obstructions
- Use high-quality components
- Regular system monitoring
- Consider seasonal variations
- Proper system sizing
