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Sizing by scenario

The questions people actually ask, answered with the full math and the units that fit. Pick the one closest to yours — then fine-tune in the sizing tool.

Informational only — a computed sizing estimate from published appliance-wattage charts and manufacturer station specs. It is not an electrical guarantee. For hardwired or whole-home backup, transfer switches, or any permanent install, consult a licensed electrician.

Power station for a home outage (fridge + CPAP + sump pump)

3,373 Wh needed 2,040 W surge 12 h horizon smallest fit: EcoFlow DELTA Pro

The classic storm-night kit: keep the fridge cold, run a CPAP overnight, and keep the sump pump ready so the basement stays dry. The sump pump’s 1,500 W startup surge is what sets the minimum inverter — here is the unit that covers all three, with room to grow.

What size power station runs a CPAP all night?

356 Wh needed 40 W surge 8.0 h horizon smallest fit: Goal Zero Yeti 500X

A CPAP without the heated humidifier sips power, so the real question is how many nights you get per charge. Here is the size for one night with comfortable headroom — and what it takes to cover several nights or to run the heated humidifier.

What size power station / battery backup for a sump pump?

1,067 Wh needed 1,500 W surge 6.0 h horizon smallest fit: Jackery Explorer 1000 v2

A sump pump only runs when the pit fills — minutes per hour, even in heavy rain — so its energy is modest, but its startup surge is brutal. The inverter has to clear about 1,500 W on a 1/3 HP pump. Here is the size that starts it reliably and keeps the basement dry through a storm.

What size power station / solar generator for van life?

2,760 Wh needed 572 W surge 12 h horizon smallest fit: Jackery Explorer 3000 Pro

Van life is a steady, modest load — a 12 V fridge, lights, devices — that you recharge with solar every day. So you size for the overnight buffer between charges, not a full 24 hours off the battery. Here is a 12-hour buffer for a typical build, plus the solar-input note that matters most: pick a unit whose solar input can replace a day’s energy before the next night.

What size power station runs a refrigerator in an outage?

1,413 Wh needed 1,200 W surge 24 h horizon smallest fit: Goal Zero Yeti 1500X

A refrigerator is the load everyone wants to save first. The trick: it only runs about a third of the time, so the watt-hours it actually needs over a day are far below its running watts × 24. Here is the size that keeps your food cold through an outage — and the math behind it.

What size power station runs a 1500 W space heater?

5,000 Wh needed 1,500 W surge 3.0 h horizon expandable: EcoFlow DELTA Pro 3

Be warned: resistive heat is the worst-case battery load. A 1,500 W heater needs a 1,500 W+ inverter and drains capacity fast — run time is roughly usable Wh ÷ 1,500. Here is the honest math, plus far more efficient ways to stay warm in an outage.

What size power station runs a window AC?

2,778 Wh needed 1,250 W surge 5.0 h horizon smallest fit: Jackery Explorer 3000 Pro

An 8,000 BTU window unit pulls about 715 W running with a ~1,250 W compressor surge. The compressor cycles, so capacity stretches further than you’d think. Here is the size to keep one room cool for an evening — and the step-up for a bigger unit or all night.

What size power station / solar generator for an off-grid cabin?

3,107 Wh needed 1,380 W surge 12 h horizon smallest fit: EcoFlow DELTA Pro

A weekend cabin runs a fridge, lights, WiFi, and electronics off solar, topped up each day. You size for the overnight-and-buffer window the battery carries alone, then match solar input to replace it by day. Here is a 12-hour buffer for a modest cabin, and the expandable units worth it if you want to coast through cloudy stretches.

What size power station for partial-home backup?

6,516 Wh needed 3,420 W surge 8.0 h horizon expandable: EcoFlow DELTA Pro 3

The essentials circuit: fridge, sump pump, furnace blower, lights, and internet — the loads a transfer switch usually feeds. The furnace blower’s startup surge dominates the inverter requirement. Here is the size that carries an essentials panel through a multi-hour outage, with expandable picks for longer.