Start with the numbers.

Solar capacity estimator

Daily energy ÷ (peak sun hours × system efficiency). Adjust the assumptions for your site.

Average operating load (W)

Operating hours per day

Assumed peak sun hours per day (1–10)Illustrative assumption, not a measured site resource.

Assumed overall efficiency (0.1–1)

Battery backup estimator

Load × hours ÷ (efficiency × usable depth of discharge). Battery and inverter limits also apply.

Essential load (W)

Required backup hours

Exact nominal battery voltage (V)

Assumed inverter efficiency (0.1–1)

Assumed depth of discharge (0.1–1)