Solar system size calculator for Pakistan homes
This solar capacity calculator estimates how many kilowatts of solar panels you may need from your appliance usage. It also gives a planning estimate for panel count, inverter capacity and battery storage.
How the solar size estimate works
The tool adds your daily appliance energy use in kWh. It then divides that load by your selected peak sun hours and system efficiency, and adds your sizing margin. Panel count is based on the panel wattage you enter.
Battery backup estimate
Battery size is based on the estimated simultaneous load, desired backup hours, usable battery depth and inverter efficiency. Real backup depends on battery chemistry, inverter settings, appliance startup surge, weather and how many loads run together.
Use this as a planning estimate
A final solar design should use your actual electricity bills, roof space, shading, orientation, inverter limits and site survey. If you want to estimate financial return after choosing a size, use the Solar ROI Calculator Pakistan. For help translating monthly bill units into a planning estimate, read the solar system size guide for Pakistan homes.
Solar system size example for a Pakistan home
Suppose a home's appliances use 10 kWh per day. If you assume 5 peak sun hours and 80% total system efficiency, the unadjusted solar array estimate is 10 ÷ (5 × 0.80) = 2.5 kW. With a 15% planning margin, the target becomes about 2.88 kW. At 585 watts per panel, dividing 2,875 by 585 gives roughly 4.9 panels, so you would round up to 5 panels as an arithmetic estimate, subject to actual roof and equipment design.
Why monthly electricity units and appliance load can differ
Electricity bills usually show monthly kWh (units). Dividing 300 units by 30 days gives roughly 10 kWh/day, but that average does not show appliance startup surges, nighttime consumption or seasonal AC demand. The calculator lets you work from appliances so you can model the load you actually want solar or batteries to support.
What matters when choosing an inverter and battery
A solar array's panel kW is different from simultaneous inverter output. Motors, pumps and air conditioners can have startup requirements beyond their steady running load. Battery storage depends on which appliances must work during an outage, backup hours, allowable discharge and conversion losses. These planning estimates cannot replace an electrician's load survey or an installer verifying wiring, protections, shading, roof structure and equipment specifications.
Solar panel size in Pakistan: what about net metering?
Grid export, net-metering or other billing eligibility depends on the current local utility and applicable regulations. This calculator estimates energy and equipment sizing; it does not predict export credits, payback or regulatory approval. For a separate financial estimate use the solar ROI calculator and enter your current tariff and installation cost assumptions.