How Many Wh Do I Need to Run a Fridge for 24 Hours During a Power Outage?
What the Specs Don’t Tell You
Fridge labels show peak wattage — not real consumption. A “150W refrigerator” doesn’t draw 150W continuously. The compressor cycles on and off, typically running 30–50% of the time depending on ambient temperature, door openings, and load.
Three variables that actually determine your Wh need:
- Running wattage: How much the compressor draws when active (usually 80–200W for household fridges)
- Duty cycle: Percentage of time the compressor runs. In summer or warm kitchens, this rises to 50–60%.
- Startup surge: Compressors need 2–3× running wattage to start. A 120W fridge may spike to 300–360W at startup. Your power station must handle this peak.
Most fridge guides ignore the duty cycle. That’s why generic recommendations are often oversized or undersized.
The Actual Calculation
Use this formula:
Add 25% safety margin
Final capacity needed = Daily Wh × 1.25
Three common fridge scenarios
| Fridge type | Running W | Duty cycle | Daily Wh | Recommended capacity |
|---|---|---|---|---|
| Small / efficient (≤18 cu ft) | 80W | 35% | 672 Wh | 840 Wh+ |
| Standard (18–25 cu ft) | 120W | 40% | 1,152 Wh | 1,440 Wh+ |
| Large / older model (25+ cu ft) | 180W | 50% | 2,160 Wh | 2,700 Wh+ |
Note: duty cycle increases 10–15% in summer or if the kitchen exceeds 75°F / 24°C.
- Standard fridge: 120W running, 40% duty cycle
- Router: 15W continuous
- 4 LED lights: 40W, 6 hours/day
Total daily: ~1,440 Wh (fridge) + 360 Wh (router) + 240 Wh (lights) = 2,040 Wh
With 25% margin: 2,550 Wh capacity needed
Realistic choice: EcoFlow Delta 2 Max (2,048 Wh) covers most hours. Bluetti AC200P or Delta Pro covers full 24h+ with margin.
Solar Generators That Cover a 24h Fridge (Honest Comparison)
| Model | Capacity | Surge W | Weight | Recharge | UPS | Price |
|---|---|---|---|---|---|---|
| EcoFlow Delta 2 | 1,024 Wh | 2,700W | 12 kg | 0.8h (AC) | ✓ 30ms | ~~~$999~~ **$1,099**~~ **$699** |
| EcoFlow Delta 2 Max | 2,048 Wh | 2,400W | 23 kg | 1.8h (AC) | ✓ 30ms | ~~$1,699~~ **$899** |
| Bluetti AC200P | 2,000 Wh | 4,800W | 27.5 kg | 2.5h (AC) | ✗ | ~~$1,299~~ **$1,299** |
| EcoFlow Delta Pro | 3,600 Wh | 7,200W | 45 kg | 2.7h (AC) | ✓ 30ms | ~~$3,299~~ **$1,799** |
| Jackery 2000 Pro | 2,160 Wh | 4,400W | 19.5 kg | 2h (AC) | ✗ | ~~$1,799~~ **$1,899** |
Honest Recommendation
For a standard household fridge running 24 hours, the EcoFlow Delta 2 Max (2,048 Wh) is the most balanced option. It handles fridge + router + lights with margin, charges quickly, includes UPS, and stays under $1,700.
What it won’t do:
- It won’t run a large older fridge (180W+) for a full 24h with other loads — you’ll get 16–18 hours maximum
- It won’t power a freezer and a fridge simultaneously without careful load management
- It’s not portable — 23 kg means it stays where you put it
Alternatives — When to Choose Each
Choose the Bluetti AC200P if: Budget matters and you don’t need UPS. It has higher surge capacity (4,800W) which handles older compressors better. No UPS means a brief power gap at switch-over — acceptable for fridges, not ideal for computers.
Choose the EcoFlow Delta Pro if: You have a large fridge AND want to also run lights, router, phone charging, and possibly a CPAP simultaneously. The 3,600 Wh gives real multi-day autonomy. Price jumps significantly but so does coverage.
Choose the EcoFlow Delta 2 (1,024 Wh) if: Your fridge is small and efficient (under 100W running), or you only need 10–12 hours of backup — not a full day. At $999, it’s the entry point that covers most short outages.
- Your outages are under 4 hours — a smaller, cheaper unit covers that
- You only need to keep phones and laptops charged — a 500 Wh station is enough and costs half
- Portability matters more than runtime — consider lighter options under 12 kg
- You have a chest freezer as well — add 30–50% to your Wh calculation
Check current prices and specs:
- EcoFlow Delta 2 Max — check current price →
- EcoFlow Delta Pro — check current price →
- Bluetti AC200P — check current price →
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Frequently Asked Questions
- How many Wh do I need to run a fridge for 24 hours?
A standard refrigerator needs 900-2,250 Wh for 24 hours. Most households land at 1,200-1,500 Wh actual consumption. Add a 25% safety margin and target a unit with at least 1,500-1,900 Wh usable capacity. - Can a 1000Wh solar generator run a fridge all day?
A 1,000 Wh solar generator can run a standard fridge for approximately 12-16 hours, not a full 24 hours. For full 24-hour coverage, you need at least 2,000 Wh capacity. - What is the duty cycle of a refrigerator?
A refrigerator compressor runs approximately 30-50% of the time, depending on ambient temperature and door openings. At 40% duty cycle, a 120W fridge draws about 1,152 Wh per day.