What is Solar Load & System Size Calculator?
The Solar Load & System Size Calculator helps Pakistani households and businesses determine the exact solar panel capacity (measured in kilowatts, or kW) needed to power their connected appliances. By entering each appliance's wattage and daily usage hours, the tool calculates your total daily energy consumption in kilowatt-hours (kWh) and recommends an appropriately sized solar system. This eliminates guesswork and prevents the common mistake of buying an undersized system that cannot meet your actual energy needs.
How to Use Solar Load & System Size Calculator
- Click "Add Appliance" and select each electrical device in your home or office (e.g., air conditioner, refrigerator, fans, lights).
- Enter the wattage rating for each appliance — this is usually printed on the device label or in the user manual.
- Set the number of hours per day you run each appliance.
- The calculator instantly totals your connected load (in watts) and daily consumption (in kWh).
- Review the recommended solar system size, inverter capacity, and estimated number of panels required.
Common Use Cases
- Homeowners planning a residential rooftop solar installation in Karachi, Lahore, or Islamabad.
- Businesses calculating their solar system requirement before requesting a supplier quote.
- Solar installers and energy consultants creating proposals for clients.
- Students and engineers studying load analysis and energy planning.
- WAPDA consumers trying to reduce their monthly electricity bill by switching to solar.
Pro Tips & Best Practices
- Always add a 20–25% buffer on top of your calculated system size to account for panel degradation, dust, and cloudy days.
- Pakistan averages 4.5–5.5 peak sun hours per day depending on region — Karachi has the highest irradiance.
- Your inverter capacity must match or exceed your total connected load (peak watts), not just your average consumption.