In Pakistan, a solar system produces roughly 4-5 units (kWh) per day per installed kW. So a 5KW system makes about 20-25 units/day and a 10KW system about 40-50 units/day. Actual output depends on sun hours, season, shading, panel quality and orientation.
A common question before buying: “how much electricity will it actually generate?” The answer decides everything your system size, your payback, and whether your 1.5-ton inverter AC runs on sunshine or keeps inflating your K-Electric or LESCO bill. Here’s a realistic guide to solar panel output in Pakistan, drawn from what Zynergy measures across 1,000+ installed projects since 2021.
Output by System Size (Typical)
Pakistan sits in one of the world’s better solar belts, averaging 4.5-5.5 peak sun hours daily across most cities. After accounting for inverter losses, wiring, dust and temperature, a properly installed system delivers about 4-5 units per day for every kW of panels on the roof. That single number lets you estimate any system size in seconds:
| System | Units/day (approx) | Units/month (approx) |
|---|---|---|
| 3KW | 12-15 | 360-450 |
| 5KW | 20-25 | 600-750 |
| 10KW | 40-50 | 1,200-1,500 |
| 20KW | 80-100 | 2,400-3,000 |
Rule of thumb: ~4-5 units/day per kW.
Treat the lower end as a winter or smog-season figure and the upper end as a clear April-June figure. A 10KW system in Karachi can touch 55 units on a cloudless May day and slip to 32 on a hazy December one yet the annual average still lands near that 4-5 units/kW band. Quotes promising 6+ units/day per kW year-round are marketing, not physics.
How Much Electricity Solar Produces: The Maths Behind the Rule
If you want to understand how much electricity solar produces rather than just take a figure on trust, the calculation is short. Daily output = system size (kW) × peak sun hours × performance ratio. Pakistani cities get 4.5-5.5 peak sun hours; a well-built system with Tier-1 panels, clean DC wiring and a quality inverter achieves a performance ratio of roughly 0.78-0.82. So a 5KW system: 5 × 5.0 × 0.80 = 20 units/day. A B-grade system with undersized cable, mismatched panels and a cheap inverter can drop that ratio below 0.70 the difference between 600 and 520 units a month from the same nameplate size. This is why two neighbouring 10KW systems can show visibly different solar generation per day on their apps: the panels get the credit, but the engineering does the work.
DC oversizing and inverter clipping
One design detail moves the daily number more than most buyers realise. Installers typically fit 10-25% more panel capacity than the inverter rating say 11.5KW of panels on a 10KW inverter because Pakistani heat means panels rarely deliver their lab wattage anyway. The oversized array reaches usable output earlier in the morning and holds it later into the afternoon, adding 2-4 units a day. On rare cool, crystal-clear days the inverter briefly “clips” the excess at its rated limit; the units lost to clipping are far smaller than the units gained across hazy mornings, smoggy winters and hot afternoons. If a quote shows panel kW exactly equal to inverter kW, ask why.
Solar Generation Per Day by City and Season
Sunlight is not uniform across Pakistan, and neither is generation. Quetta and interior Sindh lead the country; Lahore loses noticeably to winter smog; Karachi’s sea haze trims summer peaks slightly but keeps winters mild and productive. Here’s what a 10KW system typically delivers through the year:
| Season | Months | vs annual average | 10KW units/day (approx) |
|---|---|---|---|
| Peak summer | Apr-Jun | +15-25% | 48-55 |
| Monsoon | Jul-Aug | −10-20% | 34-42 |
| Autumn | Sep-Oct | near average | 42-48 |
| Smog/winter | Nov-Feb | −20-30% | 30-38 |
| Spring | Mar | +5-10% | 45-50 |
Punjab’s smog season deserves a specific mention: from November to January, Lahore, Faisalabad and Gujranwala can lose a quarter of daily output to particulate haze more than clouds cost in monsoon. Karachi systems barely notice this dip. Full seasonal detail: solar in summer & monsoon.
What Affects Your Output
- Sun hours & season the biggest variable. Generation peaks April-June and dips November-February; monsoon clouds cut Karachi and Lahore output for days at a stretch → solar in summer & monsoon.
- Shading even partial shade is disproportionate. A water tank’s shadow over two panels in a string can drag the whole string down 20-30%, because panels in series follow their weakest member. Overhead cables, parapet walls and neighbouring buildings all matter at survey stage.
- Panel quality Tier-1 panels hold output for 25+ years with warranted degradation under 0.5% annually; B-grade modules flooding the Pakistani market can lose 3-5% a year and develop hotspots within two summers.
- Orientation & tilt south-facing at roughly your latitude’s angle maximises generation on an RCC lenter roof. East-west splits on sheet roofs sacrifice 5-10% but spread output across the day, which suits net-billing self-consumption.
- Cleanliness Karachi’s coastal grime and Punjab’s dust can cost 5-15% between cleans → how to clean panels.
- Temperature output drops slightly above 25°C cell temperature; rooftop panels hit 60-70°C in June. N-type panels lose less to heat than older P-type designs.
Worked Example: A Karachi Home on K-Electric
Take a real-world case from our project files. A North Nazimabad household averages 700 units a month roughly Rs 45,000 on K-Electric’s higher slabs once fuel adjustments and taxes land. That’s 700 ÷ 30 ≈ 23 units per day. Dividing by 4.5 units/kW gives a 5.2KW requirement, so we installed a 6KW system for headroom: 6 × 4.5 ≈ 27 units/day on average, or about 810 units a month comfortably covering consumption with surplus to export. Summer output runs 29-32 units/day (matching AC season, when the home’s usage peaks at 850+ units), while December drops to 21-23. Annual generation lands near 9,700 units. With strong daytime self-consumption and net-billing export credits on the rest, the household’s effective bill fell by more than 80%, putting payback inside the typical 2.5-4 year window.
kW Solar System Units Per Day vs Your Bill
The practical use of all these numbers is matching generation to consumption. Pull a recent bill and find your monthly units (not the rupee amount tariffs distort comparisons). Divide by 30 for daily usage, then by 4.5 for an indicative system size. A 600-unit home needs ~4.5KW; a 1,200-unit home with two 1.5-ton inverter ACs needs ~9KW. One caution under NEPRA’s 2026 net-billing rules: exported units earn the notified rate, which is lower than what you pay for imports, so a kW solar system’s units per day are worth most when consumed as they’re generated. If your usage is heavily night-weighted common for working households slightly undersizing, shifting loads to daytime (water pumps, washing, AC pre-cooling) or adding a battery beats overbuilding for export.
How to Track Output After Installation
Every inverter we install since 2021 ships with a monitoring app Solis, GoodWe, Huawei and similar Tier-1 brands all report live generation, daily units and monthly curves on your phone. Check three things monthly: daily units against the 4-5/kW benchmark for the season, the peak-power reading on clear days (a 10KW array should touch 8-8.5KW around noon), and any string producing visibly less than its twin, which flags shading, a failed diode or soiling. A sudden 10%+ drop that rain doesn’t fix usually means the panels need cleaning or a connection needs attention. Catching this within days rather than months protects hundreds of units a year.
How to Estimate Your Generation & Savings
You can get a useful estimate in two minutes: monthly units ÷ 30 ÷ 4.5 = system size in kW, then size × 4.5 × 30 = expected monthly generation. To convert that into rupees saved, you need your DISCO’s slab rates, your daytime/night-time split and the current export rate which is exactly what the Solar Savings Calculator handles. For a binding figure, Zynergy’s free survey measures your actual roof, shading and load profile, and our engineers rated 4.9★ by 100+ customers give you a guaranteed generation estimate before you sign, with installation completed in 7-15 days.
FAQs
About 20-25 units per day in most Pakistani cities, averaging 600-750 units a month. Expect the top of that range from April to June and the bottom in December and January.
Roughly 1,200-1,500 units. A clear-sky summer month can exceed 1,500; a smoggy Lahore December may fall under 1,100.
Around 12-15 units per day, or 360-450 per month enough for a small home running lights, fans, a fridge and one inverter AC for part of the day.
Approximately 4-5 units per day, or 120-150 units per month. This per-kW figure scales linearly, so multiply by your system size for a quick estimate.
Shorter days mean fewer sun hours, and in Punjab the smog season blocks a further 20-30% of irradiance. Generation recovers from late February as days lengthen.
Significantly. Tier-1 panels deliver their rated wattage and degrade under 0.5% a year; B-grade panels common in Pakistan’s grey market often underperform their label from day one and fade fast.
No. Panels generate 10-40% of rated output from diffused light on overcast days, so a 10KW system still produces 10-20 units on a cloudy monsoon day.
Typically 5-15% between cleans worse near construction, main roads or the Karachi coast. A monthly wash restores it; rain helps in between.
No panels generate the power; the inverter converts it. An oversized inverter adds cost without units, while a quality, correctly sized inverter minimises conversion losses.
Between roughly 10am and 3pm, peaking near solar noon. Shifting heavy loads like water pumps and washing machines into this window maximises self-consumption under net billing.
Through the inverter’s monitoring app, which logs daily, monthly and lifetime units. Compare against ~4-5 units/kW/day for the season to confirm the system is healthy.
Slightly. Tier-1 panels are warranted to retain 85-90% of rated output after 25 years, so a 10KW system producing 45 units/day now should still manage about 40 in its third decade.
