What Size Power Station Do I Need for a Power Outage?

Step 1: Prioritize what actually needs power

Ready.gov, the U.S. government's official emergency-preparedness site, recommends taking an inventory of what in your home depends on electricity before an outage happens, including talking to your medical provider about a plan for any electrically powered medical devices and any medication that requires refrigeration.

A short list usually covers: refrigerator/freezer, phone and communication devices, lighting, internet/router if you need connectivity, and any medical equipment. Everything else — entertainment devices, non-essential appliances — is optional and can be added if capacity allows.

Step 2: Decide whether you're planning for hours or days

A short outage (a few hours) is mostly about keeping the fridge from warming up and keeping phones charged — a compact station can comfortably cover this.

A multi-day outage changes the math substantially: daily energy needs multiply by the number of days, which is why longer outages usually call for either a larger/expandable station, a recharge plan (solar or generator), or both. Size for the realistic worst case you're planning around, not just a typical short outage.

Step 3: Add up daily energy for your priority list

For each device on your priority list: watts × hours used per day = watt-hours per day, then add them together. A refrigerator alone is commonly 1,000-1,600 Wh/day; phone charging and a few LED lights add relatively little on top.

Check devices' rating labels or manuals for real watts rather than guessing — this is the same rule as every other PowerMatchLab sizing guide, and it matters more, not less, in a real outage.

Step 4: Convert to a recommended capacity

Using PowerMatchLab's standard assumptions — about 85% usable energy after conversion losses, plus roughly 20% reserve headroom: recommended minimum capacity (Wh) ≈ (daily energy Wh × days of outage) ÷ 0.85 × 1.2.

Worked example: your priority list (fridge, phones, some lights) totals 1,400 Wh/day, and you're planning for a 2-day outage. 1,400 × 2 ÷ 0.85 × 1.2 ≈ 3,953 Wh minimum recommended capacity.

Don't forget the surge, especially for the fridge

A refrigerator or freezer compressor surges to two to three times its running watts for a moment on startup. Whatever station you plan around needs a surge/peak rating that comfortably clears that spike, on top of enough continuous output for everything else running at the same time.

If you're also considering a fuel generator

A fuel-burning generator can run as long as fuel lasts, but produces carbon monoxide and must never run indoors, in a garage (even with the door open), or near windows or doors — the U.S. Consumer Product Safety Commission has documented carbon monoxide deaths tied to generators used too close to living spaces.

A battery power station avoids this risk entirely since it has no exhaust, which is one reason many households keep one specifically for the indoor-adjacent essentials (fridge, medical devices, communication) while reserving a generator, if they have one, for larger or longer-duration loads outdoors.

Recharging mid-outage

Solar input can extend a station's coverage during a multi-day outage, though real-world output is usually well below a panel's rated watts. A car's outlet or DC input, where supported, is another option if you're mobile during the outage. Plan your recharge option before you need it, not during.