Solar panel sizing

Off-grid array and battery size from daily watt-hours, sun hours, autonomy days, and losses.

Size an off-grid solar setup: panel watts from daily energy use and sun hours, battery Ah for days of autonomy.

Rule-of-thumb sizing, no shading or temperature derate. Runs in this browser.

How to use

  1. Enter daily use (Wh), panel wattage, sun hours.
  2. Set autonomy days, DoD, and system efficiency.
  3. Read panels needed and battery Ah/Wh.

What it supports

Array = Wh ÷ (sun h × efficiency), battery Wh = Wh × days ÷ DoD; panels round up to whole units of ≤ 2,000 W each. Li-ion/lead-acid DoD presets. Panel temperature, shading, and seasonal tilt are not modeled.

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