Do Solar Panels Work During Fog and Smog in Pakistan?
By PSI Editorial • June 8, 2026
Atomic Summary: During dense winter smog or heavy fog, solar panels will still generate power using diffused light, but total generation typically plummets by 50% to 70%. A 10kW system that produces 45 units in summer might only produce 12-15 units on a smoggy day. Proper cleaning and battery storage are critical.
Every November, cities like Lahore, Faisalabad, and Multan are blanketed in a thick, toxic layer of smog. It is a time when the Air Quality Index (AQI) shatters records, breathing becomes difficult, and visibility drops to near zero. Because you can barely see the sun, does your multimillion-rupee solar investment become a useless roof decoration?
With electricity prices from WAPDA and K-Electric soaring, keeping your solar generation optimized during winter is crucial. Let us dive deep into the technical realities of how solar panels handle smog and fog, the financial impact on your electric bills, and actionable steps you can take to survive the darkest months of the year.
The Science of Solar Power and Diffused Light
To understand why panels behave the way they do during winter, we have to debunk a massive misconception: Solar panels do not need heat to produce electricity; they need light (photons). In fact, high summer heat actually reduces panel efficiency.
However, when a thick layer of fog or smog rolls in, it scatters and blocks the photons from the sun. The remaining light that makes it through the gray blanket is known as diffused light. Your Tier-1 solar panels (like Longi, Jinko, or Canadian Solar) are highly advanced and can absolutely generate electricity from diffused light, but the volume of photons is severely restricted.
Alert: The Smog Mud-Cake Effect
Smog is far worse than fog. While fog is just water vapor, smog is a cocktail of dust, vehicular emissions, and industrial smoke. When morning dew mixes with smog, it settles on your panels and bakes into a thick, muddy paste as the day warms up. This blocks light entirely and can permanently stain your panel glass if left uncleaned.
How Much Generation Will You Lose?
Let us look at a realistic scenario for a standard 10kW system installed in Punjab. During a clear day in May, this system might comfortably generate 45 to 55 units (kWh) of electricity.
When the "fifth season" of smog arrives in November and December:
1. Mild Fog / Light Smog
You can expect a generation drop of about 20% to 30%. The 10kW system will output around 30 to 35 units. The inverter will likely start generating an hour later than usual and shut down earlier in the evening.
2. Dense Fog
Generation plummets by 50% to 60%. Your system might struggle to produce 18 to 22 units. In cities closer to rivers (where fog is dense), generation will remain low until the fog burns off around 1:00 PM.
3. Heavy Toxic Smog (AQI 400+)
Generation can drop by a catastrophic 70% to 80%. A 10kW system might limp along, producing just 10 to 14 units for the entire day. The sun is entirely blocked, and your inverter may even struggle to maintain a stable string voltage.
| Weather Condition | Estimated Drop | 10kW System Yield (approx) |
|---|---|---|
| Clear Summer Day | 0% (Baseline) | 45 - 55 Units |
| Clear Winter Day | -15% (Shorter days) | 38 - 42 Units |
| Dense Fog | -50% to -60% | 18 - 22 Units |
| Heavy Smog | -70% to -80% | 10 - 14 Units |
3 Crucial Steps to Optimize Winter Performance
You cannot control the weather, but you can control your solar setup. Here are three critical steps to ensure your system performs optimally during the smog season.
Step 1: Increase Your Cleaning Frequency
In the summer, cleaning your panels once every two weeks is usually sufficient. During the smog season in November and December, you must clean them at least once a week. Use a soft wiper or brush with a long handle and fresh water. Do not use harsh detergents, as they can degrade the anti-reflective coating on the panel glass. The goal is to remove the sticky smog-dew mixture before it bakes into the surface.
Step 2: Adjust the Tilt Angle
Because the sun hangs much lower on the horizon during winter, panels that are laid too flat will miss out on direct sunlight. If your mounting structure is adjustable, elevate the tilt angle by 10 to 15 degrees. A steeper angle also helps morning dew and accumulated smog dust slide off the panels more easily.
Step 3: Rely on Your Net Metering Credits
This is the ultimate financial strategy for winter. During the long, sunny days of summer, your system likely exported thousands of excess units back to WAPDA or K-Electric via your green meter. In the winter, when your system is struggling to produce 15 units a day, you will be drawing heavily from the grid to run your geysers and heaters. Your saved-up net metering credits will automatically offset this winter usage, resulting in a zero or negative bill despite the terrible generation.
Financial Tip: Battery Storage
If you face severe load-shedding during the winter, the low daytime generation might not be enough to charge your batteries fully. Consider upgrading to Lithium iron phosphate (LiFePO4) batteries which charge much faster on low current than old tubular batteries. Many banks, including Meezan Bank, offer financing schemes that cover battery upgrades.
Conclusion
Winter smog in Pakistan is a brutal reality that severely impacts solar generation. You should mentally prepare for a 50% to 70% drop in daily unit production during November and December. However, by strictly maintaining your panel cleanliness, adjusting tilt angles, and leaning on the net metering credits you banked during the summer, you can easily ride out the smog season without paying exorbitant WAPDA or K-Electric bills.
Frequently Asked Questions
Do solar panels work in heavy smog?
Yes, solar panels still work in smog by using diffused sunlight, but generation can plummet by 50% to 70%. The exact drop depends on the density of the pollution and whether a layer of dust has settled on the panels.
How often should I clean my solar panels during winter?
During the intense smog months of November and December in Punjab, you should clean your panels at least once every week. Smog mixes with dew to form a muddy, sticky layer that blocks sunlight.
Will Meezan Bank finance a hybrid inverter system?
Yes, Meezan Bank and other commercial banks provide solar financing under SBP schemes for complete hybrid systems, including Tier-1 panels, Tier-1 inverters, and lithium battery storage to combat load-shedding and low generation.