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Free Online Solar Calculator for Pakistan

Estimate your solar system from your electricity bill, monthly units, or appliance load. It is free to use online, with no signup required.

Already have import and export readings? How to calculate a net metering bill

Step 1 of 5

Where will you install solar?

We use your city's average peak sun hours to size the system correctly.

DISCO
LESCO
Peak sun hours in Lahore city
5.3 hrs / day
4.55.56.5
Pakistan solar sizing guide · reviewed 10 August 2026

How this solar calculator turns five answers into a planning estimate

A useful solar estimate connects location, electricity consumption, system architecture, usable roof area, and payment method. The guide below explains the calculation logic, what each answer changes, and what still needs to be verified before you sign an installer or bank contract.

01

City, peak-sun hours, and DISCO

Location sets the solar-resource assumption and the relevant electricity distribution company.

Pakistan has a strong solar resource, but it is not identical across Lahore, Karachi, Islamabad, Multan, Peshawar, Quetta, and other cities. We translate each city’s long-run irradiation into peak-sun hours, then apply a performance factor for heat, dust, wiring, inverter conversion, mismatch, and downtime. Your DISCO also matters because the bill format, sanctioned load, application handling, local transformer headroom, and interconnection process sit with the relevant licensee.

  • Peak-sun hours are equivalent full-power solar hours, not sunrise-to-sunset duration.
  • Seasonal output will move above and below the monthly average.
  • NEPRA’s 2026 prosumer rules make connection phase, sanctioned load, and network feasibility important checks.
02

Monthly bill, kWh, or appliance load

Energy demand determines the array size; your rupee bill is only a proxy for that demand.

The strongest starting point is the imported kWh shown across 12 recent bills. Add those units and divide by 12, or use a seasonally representative average if your household has changed. The rupee amount is less precise because a Pakistani electricity bill can combine energy charges with slabs, peak/off-peak rates, fixed charges, taxes, fuel and quarterly adjustments, arrears, and other items. Appliance mode is useful for a new property or backup circuit, but nameplate watts and assumed running hours remain indicative.

  • Use total peak plus off-peak imported units where both appear.
  • Separate recurring consumption from one-time arrears and adjustments.
  • Size future loads explicitly instead of hoping spare inverter capacity will cover them.
03

On-grid, hybrid, or off-grid solar

System type changes cost, battery requirement, outage behavior, and the value of excess generation.

An on-grid system uses the utility as its operating reference and normally stops during a grid outage. A hybrid design adds compatible storage and backup controls so selected circuits can operate when the grid fails. An off-grid system must cover the property independently, which usually requires more conservative panel and battery sizing. Under net billing, imported electricity is billed at the applicable retail tariff while exports receive a separate purchase credit, so a high daytime self-consumption ratio is more valuable than simply maximizing exports.

  • Choose critical backup loads before choosing battery kWh.
  • Check inverter surge power for motors, pumps, refrigerators, and air conditioners.
  • Confirm grid-interconnection compatibility and installer filing scope in writing.
04

Usable roof area and solar-panel layout

The physically usable, low-shade area limits how many modules the recommended system can carry.

Plot size and roof size are not interchangeable. A layout must subtract water tanks, stair rooms, parapet shadows, skylights, access corridors, drainage paths, and setbacks. Tilted modules also need row spacing to avoid self-shading. Panel dimensions and wattage change the final count, while slab condition, mounting height, wind exposure, waterproofing, earthing, and cleaning access affect the structure and installation cost.

  • Measure clear length and width in feet when possible.
  • Map shadows in winter as well as summer because the sun path changes.
  • Do not approve drilling or ballast until the structure and waterproofing method are documented.
05

Cash price, solar loan, or EMI

Payment method changes cash flow and total ownership cost, but not the roof’s energy potential.

Cash normally has the lowest total financing cost, while a bank facility preserves liquidity but adds eligibility rules and finance charges. Pakistan solar products can use fixed, variable, or hybrid pricing; KIBOR-linked offers can reprice. Banks may require equity, property documents, income evidence, approved vendors, processing fees, insurance or Takaful, and early-settlement charges. Always compare total paid and a dated amortization schedule alongside the quoted monthly installment.

  • Compare the installer cash price with the bank-approved vendor price.
  • Stress-test a variable-rate payment before selecting the longest tenure.
  • Treat estimated solar savings and the bank payment as separate cash-flow lines.

Calculator formula and assumptions

The result is a pre-feasibility estimate, not an engineering design. It uses a transparent chain of assumptions:

Recommended DC size (kW) ≈ monthly kWh ÷ 30 ÷ city peak-sun hours ÷ 0.75 performance ratio
  • The recommended kW is rounded up so normal system losses are not ignored.
  • Panel count depends on the selected panel wattage and is rounded to a whole module.
  • Generation is split between direct self-consumption and exports; those flows use different financial values.
  • The current 2026 export-credit planning input is Rs. 8.13/kWh, matching NEPRA’s CY 2026 national average energy purchase price decision. Regulations, rates, and agreement treatment can change.
  • Market prices, battery capacity, inverter configuration, roof work, protection equipment, cable route, taxes, and filing scope can move the final quote.

Pakistan solar calculator FAQs

How many months of electricity use should I enter?

Use the average imported kWh from the latest 12 months when available. A full year captures seasonal air-conditioning, heating, pump, and occupancy changes. If the property or appliances changed recently, build a forward-looking load estimate instead.

Can I size solar from the bill amount only?

Yes, but it is less exact. The calculator converts rupees to estimated kWh using a blended rate. Units from the bill are better because taxes, fixed charges, tariff slabs, fuel adjustments, arrears, and other charges do not represent electrical energy.

Will on-grid solar work during load shedding?

A conventional grid-tied system normally disconnects when the grid fails to prevent unsafe back-feed. Backup requires a properly designed hybrid or backup-capable inverter, storage, isolation or changeover equipment, and a defined critical-load circuit.

Is net metering the same as net billing in Pakistan?

People still commonly say net metering or green meter, but NEPRA’s 2026 prosumer framework describes net billing: imported kWh are charged at the applicable tariff and exported kWh receive a separate purchase credit. Existing agreements may have different treatment, so check the signed agreement and current DISCO bill.

How much roof space does a solar system need?

It depends on module dimensions, wattage, tilt, row spacing, shade, setbacks, and roof obstructions. Enter clear usable area, not total plot size. The result is a screening estimate; an installer must prepare a measured module layout and structural plan.

Should I oversize the system to earn from exported units?

Usually the stronger first objective is to cover high-value daytime consumption. Exports can still help, but their credit is separate from the retail tariff, and a proposed grid-connected capacity must also satisfy sanctioned-load and network-feasibility rules.

Are solar EMI results guaranteed?

No. They are comparison scenarios. The bank decides eligibility, vendor acceptance, valuation, benchmark, spread, fees, insurance or Takaful, security, down payment, and final schedule at approval or disbursement.

What must an installer verify after the calculator?

At minimum: 12-month load profile, site shade, module layout, slab or roof condition, wind and mounting design, inverter and battery compatibility, protection and earthing, cable routes, sanctioned load, DISCO feasibility, warranties, monitoring, bill of materials, and the exact filing scope.

Primary and technical sources used

Rules and finance terms are time-sensitive. These links are provided so you can verify the live source before making a purchase decision.

No calculator can guarantee final engineering design, generation, savings, approval, price, or a bank offer.

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