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Refrigerator Solar Calculator
A refrigerator cycles on and off. Multiplying its running watts by 24 usually misrepresents daily energy. Start with measured consumption or the annual kWh on its EnergyGuide label, and keep running power separate for inverter planning.
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Illustrative inputs · 24 V nominal battery · 2 days of autonomy · LiFePO4 assumption. No signup required.
Example daily energy budget
| Appliance | Running W | Hours/day | Quantity | Wh/day |
|---|---|---|---|---|
| Refrigerator: 365 kWh/year example | 150 | 6.67 | 1 | 1000 |
| Daily energy before system losses | 1000 Wh | |||
Convert your refrigerator energy label
1,000 Wh/day; 6.67 equivalent operating hours/day.
Use these values to edit the loaded example. If the calculated hours exceed 24, check the running wattage or energy figure.
Account for inverter standby consumption
The calculator uses a fixed 90% inverter-efficiency assumption for battery sizing. It does not separately model your inverter's no-load or standby consumption. Check the manufacturer's specifications and measure your actual setup where practical; a fixed percentage can miss a significant load in a small refrigerator system.
As a separate illustration, an inverter with a 15 W fixed overhead left on for 24 hours uses 360 Wh per day. If that overhead is not already included in your battery-side measurements or efficiency estimate, it needs its own allowance. The 15 W value is hypothetical, not a specification or default for your equipment. Do not count the same losses twice.
If the inverter already stays on for a pump or other appliance, its entire standby consumption is not an additional cost caused by the refrigerator. Equivalent compressor running hours are an energy-budget input, not a recommendation to disconnect the refrigerator on a timer.
Use the annual energy figure
Divide annual kWh by 365, then multiply by 1,000 to get average Wh per day. A hypothetical 365 kWh/year refrigerator uses 1,000 Wh/day on that basis. The label is a standardized comparison, not a guarantee in your installation. A hot room, cold ambient conditions outside the appliance's rated range, frequent door opening and ice makers can change consumption.
Convert that energy into a calculator entry
For a refrigerator drawing 150 W while running, 1,000 Wh/day ÷ 150 W is 6.67 equivalent operating hours per day. Keep it connected as required by its instructions; this number is a calculation input, not a timer setting. The example button loads the unrounded operating hours and 150 W running power. Use the converter below for your own label, then edit those two fields in the calculator.
Estimate solar and storage
For the 1,000 Wh/day example, an assumed 4.5 peak sun hours gives 1,000 ÷ 4.5 × 1.3 = 289 W before panel rounding. At 3 hours the target is 433 W. Two days of battery autonomy need 2,000 Wh delivered, or 2,469 Wh before capacity rounding using 90% depth of discharge and 90% inverter efficiency. Actual usable battery capacity, winter solar and backup arrangements matter more than nominal watts alone.
Check starting surge separately
Compressor start-up power can exceed running power. The calculator adds continuous-load headroom but does not calculate starting surge. Check the appliance and inverter manufacturer specifications, including surge duration and battery current capability. For food storage, plan an independent backup and monitor temperatures; a solar sizing estimate is not a reliability guarantee.
How equipment suggestions work
Run the calculator with your own inputs to see any available equipment candidates. Candidates are screened by the specifications stated alongside them. They are not a complete compatible kit, and prices are shown by the retailer. We do not claim to have installed or field-tested these example systems.
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Help someone plan their system
Share this editable example with a camping partner or someone planning a cabin. It opens without an account.
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Prepared by BestChain Inc. Updated September 22, 2026. About our calculation limits.