Solar Sizing Tool

Estimate solar array size required to recover daily energy use based on sun-hour assumptions, system derate, recharge timing, and planning margin.

Public calculator: You can use this tool without logging in. Logged-in builders can save solar planning profiles and optionally link them to a project.

Planning Inputs

Planning goal

Daily Solar Entry Mode

Choose whether to enter one total daily solar production number or build it from individual panel rows.

Manual Daily Solar Production Total

Daily Solar Production (Watt-Hours)

Use this if you already know your total estimated daily solar production.

Daily Energy Recovery Target

Daily Energy Target Source

Choose whether the daily energy recovery target is entered manually or pulled from a saved battery plan.

Daily Energy to Recover (Watt-Hours)

Enter the amount of energy you want your solar system to replace, in watt-hours per day.

Solar Planning Assumptions

Peak Sun Hours

Use a realistic average for your location and season. Example: 4.0

System Derate Factor

Enter as a decimal ratio, such as 0.75 for 75% net real-world performance.

Safety Margin Factor

Multiplier for extra planning margin. Example: 1.10

Reset

You do not need an account to calculate results. Save, load, project-link, and project-import features are available only to logged-in builders.

Results

Choose an entry mode, enter your planning assumptions, and select Calculate Solar Array Size to view estimated solar recovery guidance.

Planning note: Use a manual recovery target or a saved Battery profile, preview project panel imports, and choose shared or per-panel solar assumptions. Saved source values change only when you refresh them.