We calculate connected load, likely simultaneous load and the largest expected startup surge.
How this calculator works
The sizer combines appliance nameplate wattage with typical duty cycles, simultaneity, surge demand, battery losses and conservative solar production assumptions. It produces an equipment schedule and design checks instead of only converting total watts into a panel count.
Daily energy uses your hours per day and a realistic duty cycle for equipment that switches on and off.
Inverter, battery and PV recommendations each add appropriate efficiency and safety allowances, followed by an MPPT and roof-design checklist.
Worked example
A practical planning scenario
A home with two 1.5 HP air conditioners, a refrigerator, two TVs, lighting, a pump and internet equipment may have a much higher connected load than its normal running load. The calculator treats those two values separately before recommending an inverter, storage target and panel schedule.
Frequently asked questions
Is this an exact solar-system design?+
No. It is a preliminary planning estimate. A qualified engineer must verify loads, roof space, panel string voltage/current, cable routes, distribution boards and protection devices on site.
Why is battery size based on selected backup items?+
Most homes do not need every appliance during an outage. Marking essential loads prevents unnecessary battery oversizing.
Does the calculator account for air-conditioner startup?+
Yes. Motor and compressor loads include startup multipliers, which are considered separately from normal running demand.
Why does the result not guess a charge-controller quantity?+
A credible MPPT or charge-controller selection needs the exact panel Voc, Vmp, Isc, string layout, local temperature and inverter/controller limits. The result flags that design step instead of inventing a controller number from total watts alone.