What Size Solar System Do I Need for a Refrigerator?
The daily energy has to come from a published example, not from a running-watt sticker. This page uses 100 W × 5 hours and tells you to meter your own fridge.
Full breakdown: what size solar system.
Battery-side panel sizing, including the 200 W per 100 Ah lithium guideline, is on how many solar panels to charge a battery.
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The only daily energy this page will use
| Figure | Value | What it is | Source |
|---|---|---|---|
| Example fridge energy | 500 Wh | 100 W × 5 h | Battle Born battery article |
| Array at 4 peak sun hours | 125 W | 500 ÷ 4 | Battle Born panel article |
| Plus 20–30% | 150–162.5 W | 125 × 1.20 and 125 × 1.30 | Battle Born |
| Energy Star fridge, running | 132–192 W | Running watts, not Wh/day | Honda |
| Refrigerator, running | 150–400 W | Running watts, not Wh/day | Champion |
| Honda start, Energy Star fridge | 1,200 W | Starting watts, not array size | Honda |
How to size it
Do not multiply a running-watt range by 24 hours. That would invent a duty cycle. Honda lists an Energy Star refrigerator/freezer at 132–192 W running and 1,200 W to start. Champion lists a refrigerator at 150–400 W running. Those numbers tell you the machine is on or starting. They do not tell you how many hours a day the compressor runs. Battle Born's battery article is the source that actually states a daily example: 100 W × 5 h = 500 Wh. Keep that label on it — an example — and replace it with a plug-in meter.
- Example energy: 100 × 5 = 500 Wh.
- Array at 4 peak sun hours: 500 ÷ 4 = 125 W. Plus 20% = 150 W. Plus 30% = 162.5 W, about 163 W.
- At 5 peak sun hours: 500 ÷ 5 = 100 W, then 120 W and 130 W.
- Phoenix December check: 500 ÷ 4.75 = 105.3 W, then 126.3 W and 136.8 W. The annual plane-of-array value in that run is 6.54; December is the 4.75 figure.
- Illustrative 400 W panels: 162.5 ÷ 400 rounds up to 1 panel. A 200 W kit search is the shopping step for this small array; the count above is still just a divisor.
Battery amp-hours from the same watt-hours
| Autonomy | Watt-hours to store | Amp-hours at 12 V | Source |
|---|---|---|---|
| One day | 500 Wh | 41.7 Ah | Battle Born battery article (Wh ÷ 12 V) |
| Two days | double | 83.3 Ah | Battle Born: two days off-grid doubles capacity |
500 Wh ÷ 12 V = 41.7 Ah for the example day, and 83.3 Ah if you double for two days. The 12 V figure is the one in 2,400 Wh ÷ 12 V = 200 Ah. Size that bank on the battery bank sizer.
There is a second solar number that is easy to mix up with 125 W. Battle Born's panel article also says about 200 W of solar per 100 Ah of LiFePO4. The 500 Wh example at 12 V is 41.7 Ah, under 100 Ah, so that guideline is answering "how much array per battery," which is the panels-to-charge-a-battery page. It is not a revision of 500 ÷ 4.
Meter the fridge, swap 500 Wh for the measured day, and repeat the division. The solar size calculator and PVWatts are the place to do that with your sun, not Phoenix's.
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FAQ
Where does 500 Wh come from?
Battle Born's battery article uses a refrigerator example of 100 W × 5 hours = 500 Wh. It is their example. It is not a measurement of your fridge.
What array does that 500 Wh need?
500 ÷ 4 peak sun hours = 125 W. With 20 to 30 percent more, that is 150–162.5 W, and 162.5 W rounds to about 163 W.
Can I size from the 150–400 W running range?
Champion lists a refrigerator at 150–400 W running, and Honda lists an Energy Star refrigerator/freezer at 132–192 W running (1,200 W to start). Those are running or starting watts. Turning them into watt-hours needs hours of compressor run time, which these sources do not give. Use a plug-in meter.
What does 200 W per 100 Ah change?
Battle Born recommends about 200 W of solar per 100 Ah of LiFePO4. That sizes the array to the battery. The 125 W on this page sizes the array to the 500 Wh example. Both can be true; they are different questions.
Related questions
- What size solar system for a CPAP
- What size solar system for 1 kWh per day
- What size solar system for 2 kWh per day
All of these questions are listed on the topic map.
Sources
- Battle Born Batteries, How to Size a Deep Cycle Battery Bank — accessed Oct 2, 2026.
- Battle Born Batteries, How to Size Solar Panels for a Deep Cycle Battery System — accessed Oct 2, 2026.
- NREL/NLR PVWatts Version 8 API documentation — accessed Oct 2, 2026.
- PVWatts calculator — accessed Oct 2, 2026.
- Honda, What wattage generator do I need? — accessed Oct 2, 2026.
- Champion Power Equipment, Generator Wattage Chart — accessed Oct 2, 2026.