Work out your numbers
What size solar system do you actually need?
Enter your bill and when you use electricity. You get the system size, what it costs at wholesale, my 4% fee as its own line, and the payback — with every assumption listed and dated. No email, no phone number, nothing held back.
It will also tell you when solar is the wrong answer for your site. I take no margin on equipment and I am paid only once a system is commissioned and generating, so there is nothing in it for me if you buy a system that disappoints you.
Solar system size calculator
Your site
Every figure below is yours to change
This is a small system, and I will be straight about that
At around 6.1 kW, four percent of the project cost does not cover the engineering time this deserves. I will either tell you that upfront or point you to an installer I trust, rather than take the work and under-serve it. The numbers on this page are still yours to use — take them to whoever does the job.
System size
6.1 kW
Total cost
PKR 9.5 lakh
Monthly saving
PKR 30,289
Payback
2.5 years
Where your generation goes
The split that decides whether this pays
- You use it yourself
- 5,563 units/year
- Worth the full 58 PKR/unit you would otherwise pay — PKR 322,666 a year.
- Exported to the grid
- 3,709 units/year
- Bought back at 11 PKR/unit — PKR 40,797 a year.
What that means in equipment
- Capacity
- 6.1 kW
- Panels
- 9 × 715 W
- Roof area needed
- 488 sq ft
- Generation
- 9,272 units/year
- Covers
- 100% of your consumption
What it costs
Equipment at wholesale · zero margin · fee shown separately
- Equipment & installation
- PKR 915,000
- Consultancy fee — 4%, on commissioning
- PKR 36,600
- Total
- PKR 951,600
That works out at PKR 156 per watt all-in, fee included — the equipment and installation alone are PKR 150 per watt. You receive every original supplier invoice, in the supplier's own name, so what the equipment cost is what you pay. The 4% is invoiced only once the system is installed, tested and generating.
These numbers are a starting point, not a quotation. Send them to me and I will tell you which assumptions do not hold for your site — before anyone visits and before you spend anything.
Your figures go into the message — nothing is collected from this page.
What this calculation rests on
Every figure, dated and sourced — check them
- Net billing buyback
- PKR 11/unit exported
- NEPRA Prosumer Regulations 2026, net billing buyback rate · last verified 5 Aug 2026
- Residential tariff
- PKR 58/unit, unprotected, all-in
- NEPRA consumer-end tariff schedule, unprotected residential slabs · last verified 5 Aug 2026
- Industrial tariff
- PKR 52/unit, all-in
- NEPRA consumer-end tariff schedule, B-1/B-2 industrial · last verified 5 Aug 2026
- Installed cost
- PKR 120–150/watt, wholesale
- YTECH SOLAR procurement records, wholesale, no margin · last verified 5 Aug 2026
- Battery cost
- PKR 38,000/usable kWh, LiFePO4
- YTECH SOLAR procurement records — Dyness/Pylontech LiFePO4, wholesale · last verified 5 Aug 2026
- Specific yield
- 1,520 kWh/kWp/year in Lahore
- Global Solar Atlas long-term averages, checked against delivered plant data · last verified 5 Aug 2026
These are reference figures, not a quotation. The calculator cannot see your roof orientation, your shading, your existing switchgear, your sanctioned load or the condition of your connection — and any one of those can move the answer materially. What it gives you is a defensible starting point and the arithmetic behind it.
Tariffs and the buyback rate move. Anything dated more than a few months ago should be re-checked against your own bill before you spend money on it — and net billing changed the arithmetic in February 2026, so figures from before then do not apply at all.
Questions about sizing a system
- How accurate is this solar calculator?
- Accurate enough to decide whether to take the next step, and not accurate enough to order equipment from. The generation figures are based on long-term irradiance data for your city, cross-checked against measured output from systems I have commissioned, so the energy side is solid. What the calculator cannot see is your roof orientation, shading from a neighbouring building in December, the condition of your switchgear, or your sanctioned load — and any one of those can move the answer materially. Treat the result as a starting point with the arithmetic attached, not as a quotation.
- Why is the system size smaller than other companies have quoted me?
- Because this calculator sizes against the electricity you use during daylight hours, not against your total consumption or your available roof area. Since February 2026, net billing means an exported unit earns roughly a third of what a consumed unit saves you. Capacity beyond your daytime load therefore earns about a third as much as the capacity below it — it still pays, just far more slowly. A vendor selling equipment has every reason to quote you the bigger system. I take no margin on equipment, so I have none.
- What does a solar system cost in Pakistan in 2026?
- Roughly PKR 120 to 150 per watt for equipment and installation, at wholesale prices with no margin added — so about PKR 1.8 million for a 12 kW domestic system, and proportionally less per watt as size increases, because structure and cabling do not scale linearly and inverter cost per kW falls sharply above 50 kW. On top of that I charge 4%, invoiced only once the system is commissioned and generating, which takes the all-in figure to roughly PKR 125 to 156 per watt. The calculator shows both, because the equipment figure is the one to compare against a vendor quotation — their margin is inside their per-watt price rather than beside it.
- Do I need to give my phone number to see the result?
- No. The complete result is on the page — size, cost, the fee as its own line, saving and payback — with nothing held back. A calculator that hides the answer behind a contact form is a lead-capture tool rather than a calculator, and the entire model here is that the numbers are visible before you commit to anything, including every original supplier invoice once a project is running.
- How many solar panels do I need for my house in Pakistan?
- It follows from capacity rather than the other way round. At the 715 W N-Type modules I typically specify, a 10 kW system is 14 panels and a 15 kW system is 21 — but the number that matters is the kilowatts, because panel wattages differ and a quotation counting panels rather than capacity is easy to make look generous. Work out the capacity your daytime load justifies first; the panel count falls out of it.
- How much roof area does a solar system need?
- About 80 square feet per kilowatt on a flat roof with a tilted structure, which includes the spacing needed to stop one row shading the next and enough walkway to clean and inspect the array. A sloped roof facing south needs less, because the modules lie against the slope and shade nothing. For a 10 kW domestic system, budget around 800 square feet of genuinely unshaded area — water tanks, stairwell blocks and a taller building to the south all subtract from it.
- Is solar still worth it in Pakistan after net billing?
- Yes on the right site, and the calculator will tell you if yours is not. A factory, mill or cold store that runs machinery through daylight hours still pays back in a few years, because it consumes almost everything it generates at full retail value. A house whose occupants are out until evening exports most of its generation at a third of the rate, and pays back much more slowly. The regime change did not kill solar; it made the load profile matter more than the roof.
- What is not included in this estimate?
- Net metering or net billing application fees and the distribution company's own charges, any upgrade your existing switchgear or connection needs, civil work beyond standard mounting structure, and long cable runs where the array is far from the plant room. On a straightforward roof these add little. On a site needing a transformer upgrade or a 200-metre DC run, they are not trivial — which is one of the reasons nothing is quoted here before the site is seen.