What Size Power Station for a Power Outage?
Work out what you genuinely need running, not what you would like running. The gap between those two is usually a thousand dollars.
The short answer
| Profile | 24-hour draw | Capacity to buy |
|---|---|---|
| Bare minimum: fridge cycled, phones, internet | About 900Wh | 1,000Wh |
| Comfortable: fridge, internet, lamps, laptop | About 2,400Wh | 2,000Wh with discipline, or 3,000Wh |
| With a CPAP or medical device | About 2,800Wh | 3,000Wh |
| Multi-day, fridge plus freezer plus heat | About 3,500Wh/day | 4,000Wh plus solar or expansion |
The first thing to settle is what you actually need running, because there is an enormous difference between the honest list and the wish list. In practice an outage costs you four things: the food in the fridge, the internet, the ability to charge phones, and — if someone in the house depends on equipment — that equipment. Everything else is comfort.
Profile 1: the bare minimum
This is the profile most households actually fall into, and it is why a 1kWh unit is a genuinely useful purchase rather than a token one. The trick is the fridge: an unopened full fridge holds safe temperature for about four hours unaided, so you run it in bursts rather than continuously. Can a power station run a refrigerator has the detail.
Profile 2: a comfortable day
Profile 3: a household with medical equipment
If someone in the house depends on a CPAP, an oxygen concentrator or similar equipment, that load stops being negotiable and moves to the top of the list. A CPAP without a heated humidifier is 180-400Wh a night; with the humidifier it can be 500-900Wh. An oxygen concentrator is substantially more.
Profile 4: multi-day
Past 24 hours, the arithmetic stops being about capacity, because no portable unit holds three days of a household. It becomes about whether you can put energy back.
For genuinely long outages there are three honest routes: a large expandable unit (the 3.8kWh class expands to tens of kilowatt-hours), solar to recharge daily, or a fuel generator. Power station vs gas generator sets out where each wins, and it does not pretend the battery always does.
Then check the surge rating separately
Capacity tells you how long; the surge rating tells you whether the fridge will start at all. A compressor can demand three to six times its running draw for a fraction of a second, so plan for around 900W of headroom on a 150W fridge. Boost modes do not help here — they work on resistive loads, not motors. What size power station do I need covers the general method.
Four things that stretch whatever you buy
- Cycle the fridge rather than running it continuously. Thermal mass does the work between bursts, and it can cut fridge consumption roughly in half.
- Move critical loads onto UPS mode before the storm. Every unit here switches over in 10-20 ms, so the router never even reboots.
- Charge everything in advance. Phones, laptops, the power station itself. A unit at 60% when the lights go out is a much smaller unit.
- Have a lighting plan that does not use the battery. Headlamps and lanterns on their own cells cost nothing and remove a whole category of draw.
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