Plan daily solar demand clearly. Estimate load, storage, and backup needs. Create dependable system targets with practical input values.
| Appliance | Power (W) | Qty | Hours/Day | Daily Energy (Wh) |
|---|---|---|---|---|
| LED Lights | 12 | 8 | 6 | 576 |
| Fans | 70 | 4 | 8 | 2240 |
| Refrigerator | 180 | 1 | 10 | 1800 |
| Television | 90 | 2 | 5 | 900 |
| Laptop | 65 | 3 | 4 | 780 |
| Water Pump | 750 | 1 | 1.5 | 1125 |
Example total daily demand: 7421 Wh/day before system losses.
Daily energy per appliance: Power × Quantity × Hours per day
Total daily energy: Sum of all appliance daily energy values
Adjusted daily energy: Total daily energy ÷ System efficiency
Required solar array power: Adjusted daily energy ÷ Peak sun hours
Battery storage needed: Adjusted daily energy × Autonomy days
Battery amp-hours: Battery storage ÷ (Battery voltage × Depth of discharge)
Recommended inverter size: Connected load × Inverter safety factor
Panel count: Required solar array power ÷ Panel watt rating, rounded up
Enter each appliance name, wattage, quantity, and daily operating hours. Add realistic values for the devices you expect to run from the solar system.
Set the engineering assumptions next. Include peak sun hours, expected system efficiency, battery backup days, battery voltage, discharge limit, inverter margin, and panel watt rating.
Press the calculate button. The result appears below the header and above the form. Review total energy, solar array size, panel count, battery size, inverter recommendation, and the usage graph.
Use the CSV button to export summarized values for records. Use the PDF button to save a print-ready system estimate for planning discussions.
It estimates daily electrical demand, corrected solar array size, panel count, battery storage requirement, battery amp-hours, and a practical inverter rating using common engineering planning inputs.
Peak sun hours convert daily energy use into required solar array size. Fewer sun hours mean you need more solar panel wattage to deliver the same energy output.
System efficiency represents real losses from wiring, controller behavior, inverter conversion, temperature, dust, and other installation factors. Lower efficiency increases the required solar array size.
Autonomy days define how long batteries should support loads without useful solar charging. Larger autonomy increases storage needs and usually raises total project cost.
Depth of discharge limits how much stored energy you plan to use. Conservative discharge settings protect battery life, but they require a larger battery bank.
It adds a planning margin above connected running load. This helps account for startup surges, operating uncertainty, and future small load additions.
Yes. It works for homes, cabins, field stations, and small engineering projects. You should still confirm final equipment choices with site-specific electrical and safety requirements.
No. It is a practical planning calculator. Final designs should also check surge behavior, seasonal irradiance, cable losses, charge controller limits, protections, and applicable installation codes.
This calculator focuses on demand-side sizing. Good results depend on accurate load data, realistic sun-hour assumptions, and reasonable loss factors. For mission-critical systems, validate seasonal performance, battery chemistry behavior, and future expansion margins before procurement.