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The Cold You Already Own
Your refrigerator and freezer are storage tanks for cold — the generator’s job is to refill them, not to babysit them.
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Your refrigerator and freezer are storage tanks for cold — the generator’s job is to refill them, not to babysit them.
Here is the mistake almost everyone makes: they size a generator to run the refrigerator, around the clock, as if it were a light bulb. But a refrigerator is not a light bulb. It is a box of stored cold — and stored cold is fuel you already bought, sitting in your kitchen, waiting for an outage. The generator's job is not to babysit the box. It is to refill it.
The standard food-safety guidance is worth taping inside a cabinet: a refrigerator that stays closed keeps food safe for about four hours. A full freezer holds for about 48 hours; half-full, about 24. Closed is the operative word — every door-opening spends cold you cannot get back without power.
Now the load side. A modern refrigerator runs on something like 150 watts and starts on 1,000 to 1,200 — the compressor is a little air conditioner, with the same surge habit. A chest freezer is similar and holds cold even better, because the cold air does not fall out the door when you open it. These are not big loads. The reason they dominate outage planning is not their wattage — it is what spoils when they stop.
And three free moves the night before the weather arrives, none of which cost a dime: turn the freezer to its coldest setting — you are banking extra cold while the power is still free. Freeze the refrigerator things you will not need right away — milk, leftovers, fresh meat — so they start the outage frozen solid instead of merely cool. And if the freezer is half empty, push everything together into one tight igloo in the middle, because packages huddled together keep each other cold far better than packages scattered around an empty box — with the meat on the bottom, so if anything starts to thaw, its juices cannot drip onto the food below it.
If the outage looks like it will outlast the freezer — or you simply do not have a generator — there is a backup that needs no fuel, no cord, and no noise. The rule of thumb from the university extension services: about 2½ to 3 pounds of dry ice per cubic foot of freezer space, which means a 50-pound block keeps a full 18-cubic-foot freezer safe for roughly two days. Set it on top of the food, because cold sinks, with a piece of cardboard between the ice and anything it touches — dry ice is so cold it will freeze-burn whatever it rests on, food and freezer shelves included.
Dry ice has manners, and you must respect all of them. Never touch it bare-handed — it burns skin like a hot stove, only backwards; gloves or tongs, every time. Never seal it in an airtight container — it slowly turns to gas as it disappears, and a sealed container can build pressure until it bursts. And that gas is carbon dioxide, which quietly pushes breathable air out of small spaces — so keep the room ventilated, crack a car window if you are driving it home, and when you open the freezer, step back for a moment and let it breathe before you lean in. One more, for the grandkids' sake: it looks like ordinary ice and it is absolutely not a toy — keep it away from children and pets.
The final tip is the one that matters most: find out who sells dry ice before the storm. Grocery stores and ice suppliers carry it — but everyone else in the county discovers that during the outage, at the same moment you do. Write the nearest source on the card in the panel door, next to everything else future-you will be glad to find there.
Because the boxes store cold, you do not need to power them continuously — you need to top them up. The pattern that works: run the generator a few hours in the morning and a few in the evening. In each window it pulls the refrigerator and freezer back down to temperature while it also recharges the battery bank, the phones, and everything else on your list. Then it goes quiet — and the insulation does the night shift for free.
What this buys you is fuel. A generator that runs eight hours a day instead of twenty-four burns a third of the propane for nearly the same result, because most of what a round-the-clock generator does at 3am is hold a door closed that was going to stay closed anyway. The calculator's hours-per-day slider is exactly this decision — and this page is the argument for sliding it left.
One note about the machine doing the delivering. Old refrigerators were a motor and a switch and nothing else. New ones have computer boards inside — and the cheapest conventional generators put out rough, jumpy electricity that can slowly damage those boards. Inverter generators make smooth, clean power that is kind to electronics. The good news: the small inverter units this site already recommends for the generator-as-charger plan are exactly the clean-power kind — so if you have been following along, you picked right without trying. The caution is for anyone about to grab the cheapest open-frame unit off the big-box shelf to run a brand-new refrigerator: the fancier the fridge, the more its brain deserves clean power.
Two tools on this site finish the job: the Food Spoilage Timer tells you how long specific foods hold at the temperature your thermometer is showing, and if there is insulin or any refrigerated medication in that door shelf, the Medication Cold Storage calculator should be read before the storm, not during it — medicine gets a plan of its own, never a leftover corner of the food plan.
When the power comes back, the question changes from how do I keep the cold to what do I keep. The government food-safety people have clear answers, and the first one surprises everybody:
Never taste food to check if it is safe. Never. The germs that make people sick do not change how food tastes, smells, or looks. Food can be dangerous and taste completely fine — and cooking it thoroughly afterward does not undo the toxins some of those germs leave behind. You judge with a thermometer and a clock, never with your tongue.
Here is the clock: anything perishable — meat, milk, eggs, leftovers, soft cheese — that sat above 40°F for more than two hours gets thrown away. Not sniffed. Thrown away. This is what the $10 thermometer at the top of this page was hired for: when the power returns, it tells you the truth about what happened inside the box while you could not see.
Now the rule that surprises everyone in the good direction: if food still has ice crystals in it, or reads 40°F or below, it is safe to refreeze — even raw meat, and no, you do not have to cook it first. It may lose a little texture and juiciness, but it is safe. That rule saves half a freezer that most people would have thrown away on suspicion. Two footnotes travel with it: anything that raw meat juices dripped onto gets thrown out no matter how cold it is, and soft or melted ice cream goes too. Beyond that, the oldest rule in food safety still finishes the job: when in doubt, throw it out. A refilled freezer costs money; a foodborne illness at any age costs far more, and past 65 it can cost a hospital stay.
The thermometer tells you the temperature now. But what if the outage happened while you were away — evacuated, or visiting the grandkids — and the power came back before you did? The freezer refroze everything, the thermometer reads fine, and the food might still have spent a full day warm. You need a witness that stayed home. Here is one for two cents:
Before the storm, freeze a cup of water solid. Set a quarter on top of the ice, and put the cup back in the freezer. When you come home, the quarter tells the story you were not there to see. Still on top: the freezer never thawed — everything is fine. Sunk to the bottom: the freezer thawed all the way, everything melted, and it quietly refroze when the power returned — the food goes, no matter how frozen it looks. Somewhere in the middle: a partial thaw — check items one by one with the rules above.
It is the same trick as the dots on the breaker panel: two cents doing the remembering so nobody has to. One honest caveat, printed on purpose: the quarter is a hint, not a judge. The thermometer and the ice-crystal rule make the final call. But a hint that costs a quarter and works while you are two hundred miles away is a hint worth setting up — and if storms visit your area every year, just leave the cup in there year-round.