Home Power Station Selector: Capacity, Output and Solar Size

Find the right size of portable power station for home backup. List your devices, their watts and hours of use per day, and any startup surge. The selector works out daily energy, continuous and surge output, and the solar input needed to refill it in a day. It recommends a size class, never a brand.

How to use this tool

1. Keep the devices you need and remove the rest. Add rows for anything missing.
2. Enter real wattages from labels or a plug-in meter. For a refrigerator, use its average draw while cycling, not its nameplate maximum.
3. Enter hours per day and the startup surge for anything with a compressor or motor.
4. Compare the results with each power station’s usable capacity, continuous output and surge output.

Worked example

The default list (refrigerator averaging 60 watts over 24 hours, router, CPAP for 8 hours, phones, LED lamps, laptop and television) uses 2,960 watt-hours per day, or 3,552 Wh with a 20 percent margin, which points to an expandable home backup unit in the 2,500 to 6,000 Wh class. Everything running together needs at least 378 watts continuous, and the refrigerator compressor sets the surge requirement at 1,200 watts. Refilling 3,552 Wh in a day with 4.5 sun hours takes about 1,100 watts of solar.

Understanding your results

Capacity decides how long you can run your list; continuous output decides what you can run at once; surge output decides whether motors will start. If you cannot meet the daily energy with a portable unit, cut the list to true essentials, plan to recharge from a generator or solar, or consider a whole-home battery.

Common mistakes to avoid

• Using a refrigerator’s nameplate watts for 24 hours, which overstates its daily energy several times over.
• Ignoring surge ratings for fridges, freezers and pumps.
• Assuming full solar panel output. Real-world output is often well below the rating.
• Running heaters or hair dryers, which drain even large stations quickly.

Next steps

Check runtime in detail with the Home Battery Backup Calculator.

Frequently asked questions

What size power station do I need for a refrigerator?

Many modern refrigerators use roughly 1 to 2 kWh per day, so a station with at least that much usable capacity, enough continuous output for the fridge and a surge rating above its compressor start, can run one for about a day.

Can a power station run a CPAP all night?

Usually yes. A CPAP without a heated humidifier often draws only a few dozen watts, so even a mid-size station can run it for several nights. Check your machine’s power figures and your supplier’s guidance.

How much solar do I need to recharge a power station?

Divide the energy to replace by your peak sun hours and allow about 25 percent for losses. Refilling 1,000 Wh with 4.5 sun hours takes roughly 300 watts of panels in good sun.

This tool is for planning and education only. It does not store your entries. Work on home wiring must be done by a licensed electrician. Read our disclaimer.