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What size power station do I need?
List what you'll plug in and for how long. The watt-hours come from energy.gov's method, each power station's numbers come from its maker, and you see every step. Shopping for a solar generator? It's sized the same way.
Power stations that cover it
Every number comes from the maker's own product page. If a maker doesn't publish a number, the card says so. Stations that cover your list come first, smallest first.
The "check price" buttons are affiliate links.
Where the numbers come from
The energy math is the U.S. Department of Energy's. Its Energy Saver guide gives the daily formula:
(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption
Power stations are rated in watt-hours, so the tool skips the ÷ 1000. Two more rules from the same page:
- Refrigerators cycle on and off, so energy.gov says to divide the hours one is plugged in by three.
- No watts on the label? Multiply the amps by the volts. Most U.S. appliances use 120 volts.
The wattages filled in are the samples from energy.gov's appliance energy calculator (the table on this page). In energy.gov's words, they "are samples only; actual wattage of products varies". The wattage on a nameplate is the most the appliance draws, so using it keeps you on the safe side.
Sources: energy.gov, Estimating Appliance and Home Electronic Energy Use and its appliance energy calculator. energy.gov took its Energy Saver pages down in July 2026, so both links go to the Internet Archive's copies. Retrieved October 30, 2026.
Rated Wh vs what reaches the outlet
A station's capacity is the size of its battery. Some of it never reaches an AC outlet. BLUETTI is the one maker here that publishes how much: each model's FAQ gives a depth of discharge and an inverter efficiency, which leave 76.5% to 85.5% of the rated Wh for AC devices across its three models. For two of them BLUETTI also lists the station's own draw, and the tool adds that too (so does Anker's stated idle draw for the C2000 Gen 2). The other makers don't publish a usable figure, so their cards compare your need against the rated Wh and say so. Leave room on those.
Running watts and surge
Everything you mark "on at the same time" adds up, and the total has to stay under the station's rated output. Boost modes (EcoFlow X-Boost, BLUETTI Power Lifting) aren't counted: their makers describe them for heating-type loads. Motors and compressors pull extra for a moment when they start. energy.gov doesn't publish starting watts, so the tool only checks surge when you enter them from your appliance's manual or label.
Sun
If you enter sun hours, each card shows the most its solar input can take in a day: its published maximum solar watts (or your panel watts, if lower) × your sun hours. That's a ceiling. NREL lists soiling, shading, wiring and inverter losses that keep real panels below it.
Source: NREL, Technology Tips for Solar + Storage (2024), slides 6 and 14.
Recalls
Lithium-ion power stations can fail. Two had active U.S. Consumer Product Safety Commission recalls on October 30, 2026, so they're left off this list:
- EcoFlow DELTA Max 2000 (model EFD310). CPSC: "The Power Stations may overheat and ignite, posing a risk of serious burn injury and fire hazard."
- Goal Zero YETI 3000X. CPSC: "The recalled power station's circuit board can overheat, posing a risk of serious injury from fire and burn hazards."
Both fixes are free firmware updates, and CPSC tells owners to stop using the station until it's installed. Before you buy a used station, look it up on cpsc.gov/Recalls.
Questions
How do I work out what size power station I need?
Multiply each device's watts by the hours a day you'll run it, and add them up. That's energy.gov's formula, kept in watt-hours. Then check two more numbers: the watts of everything running at once, and the extra watts a motor pulls when it starts.
How long will a refrigerator run on a power station?
energy.gov says to divide the hours a refrigerator is plugged in by three, because it cycles on and off. With energy.gov's 225-watt sample, one day is 225 × 24 ÷ 3 = 1,800 Wh. Your refrigerator's label may show a different number; use yours.
Does a 1,000 Wh power station give you 1,000 Wh at the outlet?
Not all of it, and most makers don't publish how much. BLUETTI does: for the Elite 100 V2 it lists a 90% depth of discharge and an inverter efficiency over 85%, which works out to about 783 of its 1,024 Wh. For the rest, the tool compares against the rated Wh and says so.
What's the difference between running watts and surge watts?
Running (continuous) watts is what a station supplies nonstop, and everything plugged in at once has to stay under it. Surge is a short peak for motors and compressors as they start. energy.gov doesn't publish starting watts, so enter them from your appliance's manual or label.
What size solar generator do I need?
Makers use the name for a power station sold with solar panels. Jackery's Solar Generator 1000 v2, for example, is the Explorer 1000 v2 with a SolarSaga 200W panel. Size the power station the same way, then add your sun hours to see the most its solar input can refill in a day.
Can a power station run my whole house or a dryer?
energy.gov notes that larger appliances, such as clothes dryers and electric cooktops, use 240 volts. For those, or for a whole house, size a generator with GenSizer.
| energy.gov sample appliance | Watts |
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