Home battery vs standby generator

The last outage you remember is the one that matters. Four hours with a tree on the line is a different product than three days of ice.

Buy the machine for the outage you actually get, and for the things you refuse to lose: fridge, heat, well, and the little internet box so the phone still works. The ranges below are what installers and marketplaces were publishing in 2026. Your pad, gas meter, and breaker box will disagree.

The pad-mounted engine

This is the automatic kind that sits on a pad, usually on natural gas or propane. Runtime is until the fuel stops. Lights blink for a few seconds when it kicks in. It’s loud. It wants clearances from windows, a gas run, and someone to change the oil.

A typical natural-gas job is often quoted around $10,000 to $13,000 installed. Messy sites, big liquid-cooled units, and long fuel runs show up in the $16,000 to $25,000+ bucket.

The sizing guide is how big the engine should be once you’ve picked this machine.

Wall units plus a gateway

Wall units plus a gateway. Instant, silent, no exhaust. Runtime is a pile of kilowatt-hours sitting in the garage.

EnergySage’s storage cost page puts a typical install around $15,647 before incentives for about 13.5 kWh, the same usable size they associate with a Powerwall 3-class pack. That’s enough to keep essentials up. It is not enough for a whole electric furnace.

Brand-level dollars per kWh on that page (first half of 2026 quotes) run from Tesla around $967/kWh (about $13,055 at 13.5 kWh) through Enphase around $1,429/kWh and FranklinWH around $1,232/kWh, with a long tail of other brands.

EnergySage: solar battery cost

Read usable kilowatt-hours (kWh): that’s the energy you can actually take out, not the bigger number on the sticker. Some power is lost as heat, and a cold garage eats more. Want two days of fridge and well? You stack units, and the invoice doubles.

The federal storage tax credit followed the same “done by end of 2025” cliff as other IRA home credits, so don’t assume a 2026 credit on the quote. State programs are local and often waitlisted.

Hours vs days

If the outage you actually get is hours, not days (a tree on a line, the utility switching), a battery on a small “keep these circuits alive” panel is usually enough, and nicer to live with.

If it’s days, and the gas stayed up last time, a standby generator wins on runtime. Ice storms that take gas with them are a different story.

If you already have solar, a battery earns its keep on ordinary afternoons, shifting your own power. A generator earns nothing on a sunny Tuesday.

If you have a well pump, a medical device, or a sump that can’t miss, size the watts and the startup surge, then pick the machine. A 13.5 kWh pack isn’t a well-pump plan if the pump is 2 kW and the outage is 20 hours, unless everything else is off.

A four-hour switching event is a battery on a critical-load panel. Silent and instant.

A thirty-hour ice storm with gas still up is a standby generator, because runtime is the product.

A thirty-hour ice storm with trees on everything and gas pressure sketchy is a battery for the first night, a generator if you have fuel stored, or a hotel.

Portable, standby, or a battery

Installer and marketplace writeups in 2026 cluster like this.

A portable generator is hundreds to low thousands, plus a legal inlet and a sliding interlock or transfer switch so you can’t backfeed the neighborhood. Cheap hardware plus a cord in the dryer outlet is how people kill linemen.

A typical gas standby is roughly $8,000 to $20,000 installed in several regional guides. $10,000 to $13,000 is a common “nothing weird” number.

One battery unit is roughly $10,000 to $16,000 installed, and more units if you want the whole house or long runtime. EnergySage’s $15,647 average lives here.

Panel work under either option is often thousands, sometimes as much as the backup gear.

Those bands overlap on purpose. A small essentials generator can undercut a stacked battery, and a single battery can undercut a giant whole-home genset.

Quiet first night, fuel for day three

A battery covers the blink-free hours and daily cycling. A generator covers day three. That’s two invoices. People who lived through a week-long outage often wish they had the quiet first night and the fuel for day three.

You can also make either machine smaller by backing up fewer circuits. The critical-load article is that list. If you only back up eight circuits, you can stop shopping giant whole-home units. Label the breakers this weekend and remember what you actually missed last time.

Oil, filters, and a monthly exercise

Generators want oil, filters, and a monthly exercise cycle. Skip that and the first outage is a repair visit. Homeowner-cost articles often put annual service in the low hundreds.

Batteries want firmware and a place that isn’t a sauna or a freezer. They don’t drink propane on a Saturday test.

If you have solar or ugly time-of-use rates, the battery has a day job, so price that separately. If you don’t, you’re paying battery prices for generator work.

What stays on when the lights go out?

What stays on when the lights go out? Fridge, heat, well, medical, internet, lights. “Whole home” without watts is marketing.

If it’s a generator: what fuel, how does the house switch over, where’s the pad, how far from windows, who taps the gas, who pulls the permit?

If it’s a battery: how many kilowatt-hours can you actually use (not the sticker), how many kilowatts can it put out at once, and is backup the whole breaker box or a short list of circuits?

What happens when the unit can’t cover the heat? It turns things off, or you freeze.

How long is the warranty, including labor?

Start with the short list of circuits. Then pick the machine.