Power Outage
Most outages are short. Outside major storms the typical US customer loses power for a couple of hours a year, and the equipment that matters in those hours is a refrigerator, a furnace blower, a sump pump and a phone charger. The planning problem is not surviving a blackout in the abstract. It is knowing which of your loads genuinely need to keep running, and what it costs to run them.
Two numbers decide everything here, and they are not the same number. Watts decide whether a thing can start and run at all. Watt-hours decide how long it can keep running. A generator is rated in watts and limited by fuel; a battery is rated in watt-hours and limited by what it stored before the outage began. Confusing the two is the most expensive mistake in backup power, and most product marketing depends on you making it.
Work out what you actually need to run before looking at any equipment. Everything below assumes you have done that first.
What to work through
Grouped in the order they are usually needed, drawing on whichever pillar each guide lives in.
Work out what you need
Sizing comes before shopping. These are the numbers a salesperson will never ask you for.
- What Size Generator Do You Actually Need? Sizing It Without OverbuyingMost people buy too much generator. They add up the nameplate wattage of everything in the house, arrive at a frightening number, and buy a unit that…
- Watts vs Watt-Hours: Why the Number on the Box Misleads YouA power station named for its watts is sold on its watt-hours, and the two numbers answer completely different questions about whether your backup power will work.
- Appliance Surge and Running Watts: A Reference TableTypical running and surge wattage for household appliances, with the reasons the numbers vary and instructions for finding your own rather than trusting a chart.
- How to Read an EnergyGuide Label to Size Backup PowerThe yellow EnergyGuide label on your refrigerator holds the one number that actually sizes a battery or solar system, and two numbers it deliberately leaves out.
Choose the equipment
- Gas Generator, Portable Power Station, or Home Battery: Which Backup Actually Fits Your House?For most homeowners, a portable generator is the least expensive way to cover long outages, a portable power station is the simplest way to run a few…
- What a Portable Power Station Cannot Run, and WhyThe loads that sit outside the reach of portable battery backup regardless of budget, and the physical reasons the marketing never mentions them.
- How Long Will a Power Station Run a Refrigerator or Freezer?Enter your appliance's annual kWh and a power station's watt-hours to calculate refrigerator or freezer runtime, capacity, and startup compatibility.
- Why Your Rooftop Solar Shuts Off During a BlackoutGrid-tied solar systems disconnect the moment the utility goes down, by design and by code. What anti-islanding is, why it exists, and what it takes to keep your panels working in an outage.
- LiFePO4 vs Lead Acid for Backup PowerLead acid gives up half its rated capacity to depth-of-discharge limits and lasts a few hundred cycles. LiFePO4 costs more up front and less per usable kilowatt-hour over its life, with real exceptions.
Recharging without the grid
A battery that cannot be refilled is a one-shot device. Solar is the only refill that does not need fuel.
- How Many Solar Panels Does It Take to Recharge a Power Station in One Day?Refilling a 1,000Wh power station in a single day takes roughly 300W of panel in summer and 700W or more in winter, and the station's input limit often decides the answer before the panels do.
- Why Solar Panels Never Hit Their Rated WattageA 200W panel produces closer to 130W in good conditions and far less in bad ones. The five losses between the label and the battery, and how to derate honestly.
- Can You Charge a Power Station and Run the Fridge at the Same Time?Pass-through charging works on most modern power stations, but net charge rate is solar input minus load draw, and some units handle the simultaneous job badly enough to matter.
- Portable Panels vs a Permanent Array for Outage BackupPortable panels cost three to five times more per watt and produce less, but they work during an outage without a battery, a permit, or an inverter replacement. When each one is the right answer.
Connect it safely
This is the part that kills people and burns houses down. Read it before you buy a cord.
- Transfer Switch, Interlock, or Extension Cords: How Should You Connect a Portable Generator?You have sized the generator and worked out the fuel. The remaining question is how the electricity gets from the machine in the driveway to the things…
- What Size Extension Cord Do You Need for a Generator?Calculate generator extension-cord gauge from load, length, voltage drop, and cord rating without confusing wire size with plug compatibility.
Keep it running
- How Much Fuel Does a Generator Use During a Three-Day Power Outage?Nobody actually wants a gallons-per-hour figure. What people want to know is how many cans to fill, or how many propane cylinders to keep, so that a…
- How to Heat a House When the Power Is OutThe most common heating failure during a winter outage is not that the furnace broke. It is that the furnace was fine and could not run.
- How Do You Run a Well Pump During a Power Outage?A residential well pump needs surprisingly little energy over a day and a surprisingly large amount of power for about two seconds. That single…
Understand your own risk
- How Long Does the Power Actually Stay Out Where You Live?The average American household loses power for somewhere between two hours and thirty-one hours a year, depending entirely on which state it sits in.…
- How to Read a Grid Reliability Report for Your Own RegionEvery year the North American Electric Reliability Corporation publishes an assessment of whether the grid can meet demand across roughly two dozen…
Calculators for this problem
Free, no signup to see results, and the assumptions behind each figure are printed alongside it.
Solar Sizing Calculator
Array, battery bank and charge controller for the loads you actually run.
OpenPower Station Runtime Calculator
Inside the guideHow long a given battery will really run a refrigerator or freezer.
OpenGenerator Cord Size Calculator
Inside the guideGauge and length for your load, before you buy the wrong cord.
OpenIf you only read one
What Size Generator Do You Actually Need? Sizing It Without Overbuying
Most people buy too much generator. They add up the nameplate wattage of everything in the house, arrive at a frightening number, and buy a unit that…
Read thisVerified 31 Jul 2026
Most people buy too much generator. They add up the nameplate wattage of everything in the house, arrive at a frightening number, and buy a unit that…
Other problems
- Water OutageStorage, treatment, rain collection and sanitation.
- Food DisruptionStorage, preservation, cooking and calories.
- Severe WeatherShelter, alerts and household resilience.
- Home SecurityHardening, entry points and practical household defense.
- Communication FailureAlerts, radios and offline information.
- Long-Term DisruptionSlow problems: supply, water rights, self-supply, and claims worth checking.