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Solar sizing planner

Start with the appliances you use.

Add your daily loads, find a city or ZIP area, and get a clear starting estimate for solar and battery size. Technical settings stay out of the way until you need them.

Start with your numbers
Example, not your live data A day powered by sun Five example loads, 3 peak sun hours, 2 battery backup days, 12 V, 50% usable battery
  1. Coffee maker 104 Wh 625 W × 0.1664 h
  2. 12V refrigerator 576 Wh 72 W × 8 h
  3. Laptop 210 Wh 35 W × 6 h
  4. LED lights 150 Wh 30 W × 5 h
  5. Router 144 Wh 6 W × 24 h
Daily energy
1,184 Wh
Suggested array
474 W
Suggested battery
395 Ah

The night loads are included in daily energy and the battery target. This example does not simulate battery charge level.

Your inputs

Appliances in. A useful estimate out.

Start empty, add what matters, and replace every example with your own nameplate or measured value when you have one.

Add what you use each day

Choose a starting point or add your own appliance. Every value can be changed.

Every starter is an estimated, editable planning point. Check the appliance label, manual, EnergyGuide label, or a measured value when possible.

No appliances added yet.Add the items you expect to use on a normal day.

Find your planning location

Enter a U.S. Census place with its state or a five-digit ZIP code.

No location selected. Your energy and battery estimates can still update.

Monthly solar values appear after you choose a location.

Advanced settings

Lead-acid starts with a 50% usable-capacity planning default. Lithium iron phosphate starts with 80%. Both are editable assumptions, not universal limits.

Compare equipment you already own
Plan loads that may run together

Open an appliance's optional inverter details to include it. The startup check assumes one selected appliance starts while the others are running.

No appliances are selected for this optional check.

Missing something? Ask us to add it.Send an appliance for research.

We review every request before anything enters the calculator.

Appliance requests are not available in this preview.

Privacy

The method

Simple inputs with visible math.

Daily energy, historical monthly solar values, and battery choices stay separate so you can understand what changed the estimate.

Start with the energy they use each day. In the Solar Sizing Planner, choose your Starlink model and refrigerator, then enter runtime or daily watt-hours. Replace the starter estimates with your own equipment values when you have them. Add your other loads, planning location, and months to estimate solar and battery size.

  1. 01

    Add your appliances

    If you know daily runtime, energy is quantity × running watts × hours per day. If you already know daily energy, enter watt-hours directly.

  2. 02

    Find your planning location

    The search uses a bundled Census place or ZIP-area point. It does not send your search to a location provider.

  3. 03

    Choose the planning months

    Year Round uses all 12 historical monthly averages. A month range uses the leanest average in that range. You can enter your own peak sun hours under Advanced.

  4. 04

    Read your system estimate

    Daily Wh ÷ peak sun hours gives the raw array target before the fixed 20% margin. Daily Wh × backup days ÷ voltage ÷ usable capacity gives the battery target in amp-hours.

Appliance starters. Current refrigerator and freezer daily-energy ranges come from frozen snapshots of the EPA ENERGY STAR certified product datasets, accessed August 22, 2026. Running-watt examples also use NREL's 2024 Understanding Off-Grid Solar Customers, the California Air Resources Board backup-power tool, and the April 1998 U.S. Department of Energy FEMP photovoltaic guide. Every starter is editable. ENERGY STAR certification does not imply endorsement of SunPlanner.

Representative locations. U.S. Census Bureau 2025 Gazetteer Files, accessed August 22, 2026.

Monthly solar resource. NASA POWER Climatology API v2.9.7, SYN1DEG, parameter ALLSKY_SFC_SW_DWN, January 2001 through December 2020 climatology, accessed August 22, 2026. See NASA POWER's referencing guidance and NASA Earthdata data-use guidance.

Plan, then forecast

Size the system here. Plan the days ahead in SunPlanner.

This planner helps compare capacity targets. SunPlanner estimates day-to-day solar production after you enter your array and location.

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