How Much Backup Power Do You Need for a Home Outage?
BLUF — Bottom Line Up Front
Most homeowners size backup power by marketing labels rather than actual load math — and end up either under-buying or overspending. For a rural home running a refrigerator, chest freezer, CPAP, and phone charging during a 24-hour outage, your minimum usable capacity is roughly 2,340Wh. A 1,000Wh unit covers light electronics only. If food preservation or medical equipment is the priority, start at the 2,000Wh class.
Most homeowners don't know how much backup power they need until the grid goes down. The first instinct is to look at the wattage listed on a generator's box and assume it covers everything in the kitchen. In a real outage — three days during a Mississippi summer — that assumption kills batteries or trips inverters within hours.
If you're trying to keep a full freezer from thawing or a CPAP running through the night, marketing labels don't help. Sizing backup power is about matching stored energy to your specific priorities, not buying the biggest unit on the shelf.
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Starting Watts vs. Running Watts
The most common sizing mistake is ignoring surge requirements. Appliances with a motor or compressor — refrigerators, chest freezers, well pumps — require a surge of electricity to start up. That's the starting wattage. Once the motor is spinning, demand drops to the running wattage.
If your refrigerator needs 1,200 watts to start its compressor but only 150 watts to keep running, a generator rated at 1,000 watts peak output will fail immediately. It doesn't matter that the generator could theoretically run the fridge for hours; if it can't handle that initial three-second surge, the compressor never starts. Size your generator's inverter to the highest surge rating of your most critical appliance — not to the average running load.
The Load Table: Common Home Essentials
Daily Wh estimates below assume an 8-hour duty cycle — the appliance cycling on and off — not continuous full-draw operation.
| Appliance | Running Watts | Surge/Starting Watts | Daily Wh (8hr use) | Generator Tier |
|---|---|---|---|---|
| Full-size Refrigerator | 150W | 1,200W | 1,200Wh | 2,000Wh class |
| Chest Freezer | 100W | 800W | 800Wh | 1,000Wh class |
| Well Pump (1/2 HP) | 1,000W | 2,500W | 2,000Wh+ | Whole-home generator |
| Window AC (5,000 BTU) | 450W | 1,300W | 3,600Wh | 2,000Wh class (short-term) |
| CPAP (no heat) | 30W | 30W | 240Wh | 1,000Wh class |
| Box Fan | 60W | 100W | 480Wh | 1,000Wh class |
| LED Lights (10 bulbs) | 100W | 100W | 800Wh | 1,000Wh class |
| Phone/Laptop Charging | 60W | 60W | 200Wh | 1,000Wh class |
| Microwave | 1,000W | 1,500W | 100Wh (burst use) | 2,000Wh class |
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How to Add Up Your Load
Sizing involves two numbers: total wattage (how much push you need simultaneously) and total watt-hours (how much capacity is in the tank).
Start by identifying what must run at the same time. For a basic essentials setup — refrigerator, chest freezer, CPAP, phone charging — here's the math:
Surge check: The highest surge item is the refrigerator at 1,200W. Your inverter must handle at least that much to start the compressor.
Daily Wh calculation:
- Refrigerator: 1,200Wh
- Chest Freezer: 800Wh
- CPAP: 240Wh
- Phone/laptop: 100Wh
- Total: 2,340Wh per day
That puts a 1,000Wh unit out of contention for this load. A 2,000Wh unit like the Bluetti AC200L covers the first 24 hours. Without solar recharge, a 48-hour outage requires either twice the capacity or a disciplined load-shedding plan.
Which Generator Class Fits Your Situation
Apartment or condo (essentials only): If you're covering phones, a few lights, and a laptop, a 1,000Wh class unit is sufficient. The Jackery 1000 V2 sits in this tier — portable, rechargeable from a balcony panel, and appropriate for small-appliance loads. It won't handle a full-size refrigerator overnight.
House with well pump or medical equipment: A 1,000Wh unit is generally undersized here. The surge requirements of a well pump (2,500W starting) exceed what most 1,000Wh inverters can deliver. A 1,500–2,000Wh unit provides the headroom for higher-surge appliances and medical equipment that can't tolerate interruption.
Extended outages and heavy loads: Portable solar generators have a hard ceiling. Central AC, electric water heaters, and clothes dryers are outside the capability of any unit in the portable class. For those loads, a whole-home battery system or a propane/dual-fuel standby generator is the correct tool. Attempting to run a whole house on a single portable unit typically exhausts the battery in under four hours.
For a full side-by-side on the 1,000–2,000Wh units that fit most preparedness budgets, see our Best Portable Solar Generators for Home Backup.
Check Current Price - Jackery Solar Generator 1000 V2
FAQ
Will a 1,000W solar generator run my refrigerator? It depends on the surge rating of both the fridge and the generator's inverter. Many 1,000Wh units have a peak surge rating around 2,000W, which can handle a standard refrigerator's startup draw. However, the battery itself will be exhausted in 12–15 hours under a continuous refrigerator load, with no capacity left for anything else.
Do I need to include surge watts when sizing a generator? Yes. Running watts alone will not tell you whether an appliance will start. If you only account for running watts and your generator can't deliver the surge, the compressor or motor won't start at all — regardless of how much runtime the battery could theoretically provide.
How long will a solar generator last on a single charge? Divide the unit's total Wh capacity by your hourly draw. A 1,000Wh battery running a 100W load (lights and a fan) lasts roughly 10 hours. Add a refrigerator at 150W average and that drops to around 4–5 hours. Real-world runtime runs 10–20% below nameplate capacity due to inverter efficiency losses — use 85% as your working estimate.
Buying Recommendation
For a rural household where a refrigerator and chest freezer are the top priorities, a 1,000Wh unit is a single-day emergency kit at best — adequate for light electronics, not food preservation during a multi-day outage. The minimum practical baseline for food safety and basic comfort through a 48-hour outage is a 2,000Wh class unit, or a 1,000Wh unit with a compatible expansion battery.
For specific model performance in that range, see how the Anker SOLIX C1000 compares to the Jackery 1000 V2 and how the Anker SOLIX C1000 stacks up against the Bluetti AC200L.