A $30 meter and an afternoon tells you what your house actually draws, which changes every purchase below.
Do the energy audit →Most advice on how to prepare for a long power outage is a shopping list. The problem with a shopping list is that it has no failure model behind it — it tells you to buy flashlights without telling you that in a house on a well, the thing that ends the experiment on day two is not darkness, it is the toilet. Work by system instead. Each one fails in a specific way, on a specific clock, and has a cheap fix and a real fix.
Start with what your house actually draws
Every purchase downstream depends on this number, and almost nobody has it. A modern refrigerator draws something like 100 to 200 watts while the compressor runs and totals roughly 1 to 2 kWh across a day. A gas furnace does not need gas-sized power at all — the blower and control board together are usually a few hundred watts. A half-horsepower submersible well pump, on the other hand, can demand 2,000 to 3,000 watts for the second or two it takes to start, which is the single spec that determines what generator or battery you need.
Plug a clamp meter or a plug-in energy monitor onto the things that matter and write the numbers on a card in the panel. It takes an afternoon and it is the difference between sizing a generator correctly and buying twice.
Water: the system that decides how long you stay
City water usually keeps flowing during an outage because the utility has its own backup. A private well does not. Your entire reserve is whatever the pressure tank holds — typically a handful of usable gallons — and then nothing. Ready.gov’s planning figure is one gallon per person per day for drinking and sanitation, and that number doubles in serious heat. Flushing is on top of it, at roughly a gallon and a half per flush.
The cheap fix is stored water: food-grade containers, filled and dated, replaced every six months if you bottled it yourself. Fifteen gallons for a family of four covers three days plus a little slack. The real fix, for a house where the well is the only source, is either a generator circuit that runs the pump or a hand pump matched to your static water level. Which one makes sense depends almost entirely on how deep the well is.
Heat and cold
In winter the clock is set by the building envelope, not by the thermostat. A tight, well-insulated house drifts down slowly and may stay above 50°F for a couple of days in moderate cold. A drafty farmhouse loses habitability overnight. Find out which you have by watching the indoor temperature during an actual outage and writing it down — it is the most useful piece of data you will ever collect about your own house.
The cheap fix is closing the house down to one room, sleeping bags rated well below what you expect, and a plan for the plumbing. The real fix is either a heat source that needs no electricity, or enough stored energy to run the furnace blower. Summer is the mirror image and gets underestimated: heat kills more Americans than cold, and a sealed modern house with no air conditioning becomes dangerous faster than an old one with shade trees.
Food, and the freezer problem
A full freezer holds a safe temperature for about 48 hours with the door closed; half full, about 24. The single cheapest improvement is to fill the empty space with jugs of water, which turns dead air into thermal mass and buys you hours for free. Keep an appliance thermometer inside so the decision at hour 40 is a reading rather than an argument.
Separately, keep two weeks of food that requires no refrigeration and no cooking beyond boiling water. Shelf-stable calories are cheap and the failure mode of forgetting them is embarrassing rather than dangerous, which is exactly why people put it off.
Sanitation, which nobody plans for
A gravity septic system keeps working as long as you can get water into the bowl. A system with a pump tank — common where the drain field sits uphill — does not, and it fills. Know which one you have before you need to know. If it is pumped, ration water hard, and consider whether the pump belongs on the generator circuit alongside the well.
| System | Cheap fix | Real fix |
|---|---|---|
| Water (well) | 15 gal stored | Pump on generator or hand pump |
| Heat | One room, wool | Wood stove or battery for blower |
| Freezer | Water jugs, thermometer | Generator or power station |
| Sanitation | Bucket flush from stored water | Septic pump on backup circuit |
| Light | Headlamps, AA stock | Rechargeables plus solar panel |
| Medical | Cooler and ice for insulin | Battery sized to the device |
| Comms | Car charger | NOAA radio, cell booster |
Power: the order to buy in
Start at the bottom, not the top. A pair of headlamps and a stock of batteries beats a lantern. A power station in the 1 to 2 kWh range will carry phones, a router, LEDs and a fridge cycled a few hours a day — see how long a battery actually runs a refrigerator for the arithmetic. A portable generator adds the well pump and the furnace, but only if it is wired in through a transfer switch or an interlock rather than trailing cords through a window. A standby unit removes the labor and adds a fuel line, a permit and several thousand dollars.
Two honest drawbacks nobody mentions in the ads. Batteries lose meaningful capacity in the cold, so a power station in an unheated garage delivers less than its label in January. And a generator is a machine with a carburetor that will not start in year three if it has sat with ethanol fuel in it — exercise it monthly or fit a fuel shutoff and run it dry.
Safety: Any engine, and any unvented heater, means carbon monoxide. Generators belong outdoors, more than 20 feet from windows, doors and vents. Fit battery CO alarms on every level and replace them at about five years — the sensors age out whether or not the unit is chirping.
The medical and personal layer
Refrigerated medication needs a cooler and a plan for ice, not a hope. Anyone dependent on a device — a CPAP, an oxygen concentrator, a powered wheelchair — needs a specific battery sized to that specific device, and it is worth doing that math on a calm afternoon rather than at midnight. Keeping a CPAP running is the common case and it is easier than most people expect. Register with the utility’s medical priority list if one exists in your area; it does not guarantee anything but it changes where you sit in the restoration queue.
How we would spend the first $500
Roughly: fifteen gallons of stored water and the containers, a case of shelf-stable food, four headlamps and a battery stock, two CO alarms, an appliance thermometer for the freezer, a NOAA weather radio, and whatever is left over toward a mid-size power station. That combination handles a three-day outage in any season without a single engine, and it is the base every larger purchase sits on.
What we would not do is buy the generator first. The households that end up disappointed are almost always the ones that spent four thousand dollars on power and still had no water, because the well pump was never on the transfer switch and nobody had checked. The sequence — measure, then water, then heat, then power — is what makes the money work.
Frequently Asked Questions
How many days should I prepare for?
Three days is the standard baseline and covers the large majority of outages. If you are at the end of a rural line, on the last circuit crews reach, plan for a week — that is where the difference between stored water and a working pump starts to matter.
Do I need a generator if I have a wood stove?
The stove solves heat and nothing else. The well pump, the freezer and the septic pump all still need electricity, so the two are complements rather than alternatives.
Is stored water safe after six months?
Commercially bottled water keeps well past that in a cool dark place. Water you bottled yourself should be rotated every six months, in food-grade containers that have been properly sanitized.
What is the most common thing people forget?
A manual way to open the garage door, and cash. Card readers are down at the same time your neighbors’ are, and an electric opener with no release cord strands the vehicle you were counting on.