Tick what must stay on and how long an outage you want to ride out. The sizer works out the watts and kilowatt-hours, then prices four ways to cover them.
Installer matching is not live on this site yet. Give this spec to two or three local installers so their quotes are comparable.
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Power. Running watts are the sum of everything ticked. Starting watts add the single largest motor surge on top, the standard generator worksheet method. Energy. Each appliance carries a typical kWh-per-day figure, since a refrigerator rated 700 W runs only part of each hour. Those daily figures are estimates; a hot or cold spell raises them.
Prices. Power station: about $2,800 per 4 kWh, 4,000 W unit, and an assumed $2,000 per added battery. Portable generator: $500 to $2,200 by size, plus about $650 for an electrician-fitted inlet and interlock. Standby generator: $6,000 to $22,000 installed by size, plus an assumed $1,500 for a propane tank where there is no gas line. Home battery: about $13,500 installed for the first 13.5 kWh unit and about $9,000 for each one after. There is no federal tax credit for home batteries bought in 2026. Gasoline is priced at $3.20 a gallon. Fuel-burn rates are approximations.
Context. In a normal year the average US customer loses power for about two hours. Storm years are different: South Carolina customers averaged 53 hours in 2024.
Run any engine generator outdoors, well away from doors and windows. Carbon monoxide kills indoors and in garages. Have a licensed electrician fit the inlet, interlock or transfer switch; never back-feed a wall outlet.