How many solar panels to run a refrigerator?
A household fridge running at 200 W about a third of the time uses about 1,778 Wh a day through an inverter. At 4.5 peak sun hours that takes about 479 W of panels — 2 panels of 400 W — plus about 87 Ah of 12.8 V LiFePO4 for the night half.
How to work it out
- 200 W × 8 h ÷ 90% inverter = 1,778 Wh a day
- 50% through a battery at 92% round trip → 1,855 Wh from the panels
- ÷ (4.5 sun h × 86%) = 479 W → 2 panels of 400 W
The fridge is the load everyone wants to keep on solar, and the one most often mis-sized, because it runs day and night but only cycles on part of the time. This page uses 200 W running for 8 hours a day — the extension-service one-in-three rule.
Adjust for your project
More options: From battery · Losses
- Solar array needed
- 479 W
- Energy per day (from the system)
- 1,778 Wh
- LiFePO4 battery for the night share (12.8 V)
- 87 Ah
- Figures used
- 200 W × 8 h a day (typical)
- Champion lists 150–400 running watts; a fridge runs at full power about a third of the time (Virginia Cooperative Extension).
Panels for each appliance at the sun hours above
| Appliance | Energy per day (from the system) | Solar array needed | Panels |
|---|---|---|---|
| Refrigerator (household) | 1,778 Wh | 479 W | 2 panels |
| Chest or upright freezer | 1,333 Wh | 360 W | 1 panel |
| CPAP (no heated humidifier) | 533 Wh | 144 W | 1 panel |
| Window AC, 10,000 BTU | 8,889 Wh | 2,397 W | 6 panels |
| Mini-split, 12,000 BTU | 10,667 Wh | 2,876 W | 8 panels |
| Pool pump (example: 1,900 W input) | 16,889 Wh | 4,554 W | 12 panels |
What to know about powering a fridge from solar
- Read the EnergyGuide label. A fridge listed at 500 kWh a year uses about 1,370 Wh a day; enter its watts and hours so the daily figure matches, and you have a far better number than any rule of thumb.
- Night is half the job. The fridge keeps running after dark, so about half its energy comes from a battery, which costs more than the panels.
- Add a freezer and it nearly doubles. A chest freezer at 150 W, also a third of the time, adds about 1,333 Wh a day and roughly another 360 W of panel.
- The start surge sets the inverter. Champion lists 800–1,200 starting watts for a household fridge; a 1,000 W inverter can struggle. See what size inverter for a refrigerator.
The daily energy on its own is on how many watts a refrigerator uses per day. In an outage, the quickest fixes are how long a power station runs a refrigerator and what size generator to run a refrigerator.
Different size? Use the full Solar Panels for One Appliance.
What you’ll need
- Plug-in electricity usage monitorBudget price
Plugs in between the wall and a 120 V appliance and shows real watts and kWh over a day — the honest way to fill in a load list, especially for fridges that cycle on and off.
See options on Amazon (opens in a new tab) - 400 W residential-size solar panelPremium price
Fewer, larger panels for a cabin, shed or ground mount. Their higher voltage usually means an MPPT controller.
See options on Amazon (opens in a new tab) - 12 V 100 Ah LiFePO4 batteryPremium price
About 1.28 kWh rated in a box roughly the size of a group 24–31 lead-acid battery at around half the weight. Check the BMS discharge limit and whether it can charge below freezing.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many solar panels to run a refrigerator and a freezer?
About 839 W — 3 panels of 400 W — for 350 W combined running a third of the time.
How many 100 W solar panels to run a refrigerator?
About 5 panels (479 W) at 4.5 peak sun hours.
How many solar panels to run a small 12 V-style fridge using 100 W a third of the time?
About 240 W of panels at 4.5 sun hours.
Other common sizes
- How many solar panels to run a mini split — 8 × 400 W panels (2,816 W)
- How many solar panels to run a pool pump — 11 × 400 W panels for a 1,900 W pump (example)
Sources
- Champion Power Equipment — Generator Wattage Chart (opens in a new tab) — Typical running and starting watts for household, RV and job-site appliances (a manufacturer’s planning chart — your nameplate wins).
- Virginia Cooperative Extension, BSE-301: Estimating Appliance and Home Electronic Energy Use (2020) (opens in a new tab) — Wattage × hours ÷ 1,000 = kWh per day; watts = amps × volts when only amps are listed; a refrigerator runs at full wattage about a third of the time; typical nameplate wattages.
- ENERGY STAR — Pool pumps (opens in a new tab) — Running a pool pump at half speed uses about one-eighth as much energy.
- Victron Energy — Energy Unlimited (book) (opens in a new tab) — Lead-acid charge efficiency 80–95% (85% suggested as a starting value); battery energy efficiency about 75% for full cycles, about 89% in partial state of charge; inverter efficiencies above 90%.
- Victron Energy — Lithium Battery Smart manual, technical data (opens in a new tab) — LiFePO4 12.8 V: cycle life 2,500 at 80% DoD, 3,000 at 70%, 5,000 at 50% (to 80% of capacity); 92% round-trip efficiency; 12.8 V 100 Ah: recommended continuous discharge ≤100 A (1C), maximum 200 A; capacity about 20% lower at 0 °C; charge only between +5 °C and +50 °C.
- National Laboratory of the Rockies (formerly NREL) — PVWatts® Calculator (opens in a new tab) — Look up the solar resource (peak sun hours) and yearly output for your own address; default system losses 14%.