Outage cost from your own hours, not a national figure

Outages are not getting longer every week. They are getting longer in the tail

The tail, not the average, is the finding that changes the decision, and the headline number everybody quotes conceals it completely.

The headline first. EIA: “U.S. electricity customers experienced an average of 11 hours of electricity interruptions in 2024” — nearly twice as many as the annual average experienced in the decade before. Read alone, that sounds like general decay of the grid.

Then the composition. “Interruptions attributed to major events averaged nearly nine hours in 2024, compared with an average of nearly four hours per year in 2014 through 2023. Service interruptions that aren’t triggered by major events routinely average about two hours per year.”

About two hours of the eleven is the ordinary year. Nearly nine is storms.

Why that distinction decides everything here. Two hours a year, spread over a handful of brief interruptions, costs a household almost nothing: the fridge stays cold, the evening is inconvenient, nothing spoils.

Nine hours arriving as one continuous event in the middle of a hurricane is a completely different experience — and it may not arrive at all in a given year, then arrive as three days.

So an average is precisely the wrong summary statistic. Backup power is bought against the tail, not the mean. A household whose supply is underground in a mild climate and one at the end of an overhead rural feeder can share a national average and have nothing else in common.

Which is why this tool asks you to type the hours. Your own history — how many events, how long, and how recently — is the only input that describes your risk.

Many utilities publish their own reliability statistics, and your own memory of the last five years is a better guide than any national figure.

And why we publish no dollar figure. There is no national figure for what an outage costs a household. The EIA duration data is real; the dollar value of your own lost food, lost work and hotel night is yours to type.

The food question, with an honest note about the source

Food safety is the most-asked question in an outage and the one we most want to get right, so here is exactly what we know and how well we know it.

What is consistently reported. An unopened refrigerator is consistently reported to hold food safely for about 4 hours, a full freezer for about 48 hours and a half-full freezer for about 24 hours, with 40°F as the threshold above which perishable food held for more than 2 hours should be discarded.

What we could not do. both the FSIS page and foodsafety.gov returned HTTP 403 to automated retrieval on 5 September 2026, so these figures are recorded as consistently reported USDA guidance rather than as text we read this session.

Confirm them against the live page before relying on them. We are telling you that rather than presenting a clean citation we do not have, because on a question with a health consequence the difference between "we read this today" and "this is widely reported" matters.

The mechanism behind the numbers. A refrigerator is an insulated box with very little thermal mass in it, so it warms relatively quickly.

A freezer is an insulated box containing a large mass of ice, and ice absorbs a great deal of heat while melting without changing temperature.

That is why the freezer figure is an order of magnitude longer, and why a full freezer outlasts an empty one.

Which produces two free actions. Keep both doors shut — every opening exchanges the cold air for room air. And before a forecast storm, fill the empty space in the freezer with containers of water, which converts unused volume into thermal mass at no cost.

And one rule that does not depend on any of the figures. Do not judge food by taste or smell. The pathogens that matter do not reliably announce themselves, and the amount of money at stake in a fridge is not worth the risk. If it was above temperature for a long time, it goes.

A note on insurance. Some homeowner policies cover food spoilage from a power interruption, sometimes with a small sublimit and sometimes only where the outage originates on your property. It is worth ten minutes with your own policy before you throw everything away, and photographs cost nothing.

Whether backup power pays for itself, and why the question is usually mis-framed

Households ask for a payback period. Payback is the wrong frame for this purchase, and being clear about why makes the decision easier rather than harder.

Backup power is insurance, not an investment. Nobody asks what the payback period on their house insurance is, because the purchase is understood as buying out a tail risk rather than earning a return.

Standby power is the same shape of purchase, and framing it as an investment produces answers that look bad for the wrong reason.

The arithmetic against it, stated fairly. If routine interruption is about 2 hours a year, and your household loses very little in a two-hour outage, then the expected annual saving from a standby installation is close to nothing and the payback period is effectively infinite.

That is a real and honest result, and for many households it is the correct one.

The arithmetic for it, also stated fairly. If your answer to "how many hours were you off last year" is measured in days rather than hours, the tail is doing the deciding and the average is irrelevant.

The same holds if you are on a well, have medical equipment, work from home without an alternative, or live where a cold snap could freeze your plumbing.

And the cheaper options between nothing and everything. A portable set with cords to a refrigerator and a furnace fan covers much of the value at a fraction of the cost and with no installation.

A battery for a router and a phone covers the information problem for almost nothing. Not every answer to this question is a standby installation.

Whatever you buy, the exhaust rule does not move. CPSC: “Operate generators outdoors only, at least 20 feet from homes and buildings, with exhaust directed away from windows, doors and vents.”

And: “Never use a portable generator inside homes, garages, basements, crawlspaces, sheds or other enclosed areas, even if doors or windows are open.” The most expensive outcome in this entire subject is not spoiled food.