Given a system size, see exactly how much electricity it will produce — including the month-by-month breakdown most calculators skip.
Based on system size and sun hours — actual output also depends on shading, orientation and panel degradation over time.
| Month | Peak sun hours/day | Estimated production |
|---|
The month-to-month swing exists because day length and the sun's angle both shift with the seasons — production peaks in local summer and dips in local winter, more sharply the further you are from the equator. This is a smooth seasonal approximation, not satellite-measured data; for a site-specific, engineering-grade estimate, cross-check against PVWatts or PVGIS.
Multiply your system size in kW by your local peak sun hours per day and a system efficiency factor of about 80% to get daily kWh output, then scale up for monthly and annual totals — production varies significantly by season.
Day length and the sun's angle both shift with the seasons, so production peaks in local summer and dips in local winter — the swing is larger the further you are from the equator.