Home Backup Power Without a Generator (Start With the Math, Not the Machine)

Home Backup Power Without a Generator (Start With the Math, Not the Machine)

Work out what you actually need to power before you buy anything. Most households discover the honest answer is a phone, a few LED lights, a radio, and — if someone depends on it — a medical device or a fridge holding insulin. That is a very small amount of electricity, and it does not need a generator. It needs a battery you can recharge.

A generator is a bridge, not a destination. It doesn't make energy, it spends it, burning fuel you can't replace. That's fine for a two-day storm outage. It's the wrong plan for anything longer.

Why a generator isn't the answer people think it is

Four reasons, and they're all practical:

• The fuel expires. Petrol goes stale in roughly three to six months whether you touch it or not. The can in the shed from last winter may not start the engine this winter.
• The fuel runs out fast. A generator empties its store in days, and the moment it does you have an expensive metal box.
• It's loud. In a normal outage that's an annoyance. In a longer or more serious one, a running generator announces to the whole street that this house has fuel and machines. Worth thinking about before you rely on it as your only plan.
• It kills people every single storm season. Exhaust is carbon monoxide — colourless, odourless. Outdoors only, well away from windows and doors, never in a garage even with the door open. The same rule as heating a room without electricity, and for the same reason.

If you already own one, keep it. Run it in short bursts, in daylight, to do the heavy jobs and refill your batteries — not continuously to keep the house feeling normal. And if you're buying fuel to store, propane keeps indefinitely where petrol doesn't. It stores upright, outdoors, and it's the patient choice.

Step one: rank your loads, don't power everything

Sort every electrical thing you own into three tiers. This is the step that saves the most money, because most of what people plan to power turns out to be tier three.

Anything that makes heat — kettle, toaster, heater, hair dryer — is enormously expensive in electrical terms and should essentially never come off a battery. Boil water on gas or a camp stove instead.

Step two: do the arithmetic

It's one line: wattage × hours = watt-hours per day.

Without the fridge, that entire list is 325 watt-hours a day — a modest portable power station handles it. Add the fridge and you're at roughly 1,500, which is a different and much more expensive machine. The fridge is almost always the decision point, so decide about it deliberately rather than by accident.

To size a battery bank from that number:

watt-hours ÷ battery voltage ÷ usable depth of discharge = amp-hours needed

1,000 watt-hours a day, at 12 volts, on lead-acid you shouldn't drain past 50%, is 1000 ÷ 12 ÷ 0.5 ≈ 167 amp-hours minimum. Lithium tolerates deeper discharge, so the same job needs a smaller bank — which is much of why it costs more per unit and often less per useful watt-hour.

Step three: put a little back each day

Solar is where nearly everyone should start. No moving parts, silent, and a panel lying flat on a roof doesn't look like anything worth stealing.

Rough guide to what different sizes actually do:

• ~400 W — keeps phones charged and LED lights running. Covers the survival-critical tier for most households.
• ~1,000 W — runs small appliances and helps carry a fridge.
• ~3,000 W and up — genuinely supplements a household.

One thing that surprises people: shade hurts far more than it looks like it should. A single branch or a chimney's shadow across part of a panel drags the whole panel's output down disproportionately. Placement beats panel size.

Step four: the cheapest watt is the one you never use

Before spending anything on generation, spend nothing on reduction:

• LED bulbs use about a tenth the power of incandescent.
• Kill phantom loads — devices sipping current on standby.
• Insulate. Every watt you don't spend on heat is a watt you don't have to make.
• Run heavy jobs in daylight, while the sun is doing the work directly.
• Let other things do electricity's job — gas or wood for cooking, a cool cellar or north-facing room for short-term food storage.

And keep one thing that works when the electronics don't: a hand-crank generator (5–20 W — enough for a radio and a slow phone charge) or a bicycle-driven alternator (50–100 W). Neither is efficient. Both work when nothing else does.

Do this today

Two things, both free.

Count your actual load. Walk the house and write down what genuinely must keep running. Most people are surprised how short the list is — and the short list is affordable, where "keep the house running" isn't.

Charge what you already own. A phone power bank sitting at 30% is the most common preparedness failure there is. Top up every power bank in the drawer tonight, and put a note in your calendar to do it every few months. That single habit covers the first day of most outages, which is the only day the majority of outages last.

Decide what needs feeding, harvest a little each day, store it carefully. This is a condensed version of the energy chapter in After Doomsday: The Complete Preparedness Manual, which covers load budgeting, solar, wind and micro-hydro, battery bank care, and fuel storage in full.

— Ryan T. Hale

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