β˜€οΈ Solar Tool

Solar Load Calculator & System Size Estimator

Find out exactly what size solar system your home or business needs. Enter your appliances (or pick your plot size), and get your recommended kW system, battery backup, estimated cost in PKR, and monthly savings β€” with a downloadable report. Built for Pakistan's homes, shops, and farms.

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Customer Details

For your report (not stored anywhere)

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Property & Quick Fill

Pick a size to pre-fill a typical load

Tip: tapping a size fills typical quantities below β€” then edit anything to match your home.
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Appliance Load

Qty Β· Watts (editable) Β· Hours/day

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System, Battery & Savings

Choose type and backup

On-grid uses net metering (no battery). Hybrid & Off-grid include battery backup.
βš™οΈ Cost & assumption settings (editable)
⚠️ Prices and tariff are placeholders β€” update them to your current local market rates for an accurate estimate.
β€” kW
Recommended Solar System
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Connected Load (kW)
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Daily Units (kWh)
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Monthly Units
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Panels Needed
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Solar Output/mo
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Battery Bank
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Estimated System Cost
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System Components

Indicative bill of materials

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Monthly Saving
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Yearly Saving
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Payback (years)
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ROI / year
πŸ“Š Daily Energy by Category (kWh)
β˜€οΈ Solar Output vs Usage (monthly kWh)
πŸ’° Cumulative Savings vs Cost (years)
This is a planning estimate. A site survey by a certified installer is recommended before purchase. Prices and net-metering rules vary by city and change over time β€” verify current figures locally.

What Is a Solar Load Assessment?

A solar load assessment works out how much electricity your home or business actually uses, and from that, the right size of solar system to install. Oversize it and you waste money; undersize it and you keep paying heavy electricity bills. Getting the size right is the single most important step before buying solar.

This calculator does it in three steps: it adds up your connected load (the total wattage of all your appliances), estimates your daily energy use in units (kWh) based on how many hours each appliance runs, and then recommends a solar system size in kW β€” along with battery backup, an estimated cost in PKR, and your expected monthly savings.

In Pakistan, "units" on your electricity bill means kilowatt-hours (kWh). A 1000-watt appliance running for one hour uses one unit.

How Solar System Sizing Works

Your solar system is sized mainly from your daily units, not just the connected load β€” because what matters is the energy you consume over a day, not the instant a few appliances switch on together. This calculator uses the following guide:

Daily Use (Units/kWh)Recommended SystemTypical Suits
0 – 10 units3 kWSmall home, 3–5 Marla, basic load
10 – 20 units5 kW5–7 Marla home with 1 AC
20 – 35 units8 kW7–10 Marla, 2 ACs
35 – 50 units10 kW10 Marla, multiple ACs
50 – 70 units15 kW1 Kanal house / small shop
70 – 100 units20 kWLarge home / commercial
100+ unitsCustom designIndustrial / heavy commercial

The number of panels is then worked out by dividing the system size by the panel wattage. For example, a 5 kW system using 550-watt panels needs about ten panels.

On-Grid vs Hybrid vs Off-Grid

TypeBatteryBest For
On-GridNo batteryLowest cost; uses net metering to sell surplus to the grid and offset bills. No backup during load-shedding.
HybridWith batteryMost popular in Pakistan β€” runs on solar, stores backup for load-shedding, and can still use the grid. Higher cost.
Off-GridLarge batteryNo grid connection at all (remote farms, tube wells). Needs the biggest battery bank, so it is the most expensive.
πŸ’‘ For most homes facing load-shedding, a hybrid system gives the best balance of savings and backup. If your grid supply is stable and you mainly want to cut bills, on-grid with net metering is the cheapest route.

About Net Metering & Savings in Pakistan

Net metering lets an on-grid solar system export surplus daytime electricity to the grid, which is credited against the units you draw at night β€” effectively running your meter backwards. It is the main reason on-grid solar pays back quickly on a high bill.

Your actual savings depend on your electricity tariff (which rises with usage slabs), how much of your generation you use versus export, and your provider's current net-metering terms. Because tariffs, equipment prices, and net-metering policy change regularly, treat the cost and savings figures here as planning estimates.

⚠️ Always confirm the latest tariff, net-metering rules and equipment prices with your local electricity company (DISCO) and a certified installer before making a decision β€” these change over time and vary by city.

Tips for an Accurate Estimate

  • Use realistic running hours. A 1500 W iron used 30 minutes a day uses far less energy than an AC running 8 hours β€” hours matter as much as wattage.
  • Tick "Inverter AC" if you have them. Inverter ACs use roughly a third less energy, which noticeably changes your system size.
  • Match the tariff to your bill. Enter your real per-unit rate from a recent bill for a closer savings figure.
  • Account for future load. If you plan to add an AC or a tube well, size slightly higher now.
  • Check your roof. The calculator estimates roof area needed β€” make sure you have enough shade-free space.

Frequently Asked Questions

Yes β€” completely free, with no signup. It runs entirely in your browser; your details are used only to label your report and are not stored or sent anywhere.
The cost is an indicative estimate based on the price-per-watt you set and the recommended system size. Real prices vary by brand, city, and the day's market, so update the editable price field with current local rates and always get a written quotation before buying.
It depends on your appliances, but a typical 5 Marla home with one AC, fans, lights, a fridge and a pump often lands around a 5 kW system. Tap the "5 Marla" button to auto-fill a typical load, then adjust it to your actual appliances for a tailored result.
Only if you want backup during load-shedding (hybrid) or have no grid at all (off-grid). On-grid systems with net metering use no batteries and are cheaper, but give no backup when the grid is down. Choose the system type in the calculator to see the difference.
For each appliance: quantity Γ— wattage Γ— hours used per day, divided by 1000, gives units (kWh) per day. The calculator adds these up across all your appliances and uses the total to recommend a system size.
Yes. You can download a PDF report, print the page, or export a CSV file that opens in Excel β€” all from the buttons under the results.