What you will see
- Daily totals well below summer, even on days that look clear.
- A flatter, lower curve on hazy days.
- Better days straight after rain, when the air clears.
Why it happens
Smog is a layer of fine particles that scatters and absorbs sunlight before it reaches the ground. Shorter days and a lower sun in winter reduce output further. None of this is a fault, and no cleaning will fix the haze itself.
Smog also leaves a sticky grey film on the glass, which cleaning does fix. Separating the two is the key.
What you can check yourself
- Compare this winter with last winter, not with summer.
- Look at a day just after rain. If output recovers, the panels are healthy.
- Wash the panels and compare the next similar day.
- Ask a neighbour with solar whether their totals fell by a similar amount.
What not to do
- Do not judge the system on a single smoggy day.
- Do not wash panels more aggressively to chase smog losses. Plain water and a soft brush are enough.
When to call us
- Your drop is much larger than last winter’s.
- Output stays low after rain and a wash.
Winter output in Lahore and Faisalabad
Smog affects Lahore most, but Faisalabad and much of central Punjab see the same winter haze. Compare this winter with last winter, and send us both if the drop looks too large.
Send us
Daily totals for this December and last December, and a photo of the array.