Standby generator or home battery: which is right for your home?

How each one works

A standby generator sits on a pad outside your home and connects to your gas line or a propane tank. When the power goes out, it starts on its own within seconds, and the transfer switch moves your home over to generator power. When the power comes back, it switches you back and shuts itself off.

A home battery hangs on a wall or sits beside the house and stores electricity, either from the grid or from solar panels. When the power goes out, it takes over. Once it runs down, it needs sun (or the grid) to fill back up.

The big difference: how long it lasts

A battery holds a fixed amount of energy. Tesla lists one Powerwall at 13.5 kWh. How long that lasts depends on what you run. A fridge, lights, Wi-Fi and a few outlets can stretch it a long way. Add central air in an Atlanta July, or electric heat during an ice storm, and it goes much faster. You can add more batteries, and solar can recharge them, but a cloudy winter week doesn't give much back.

A standby generator on natural gas has no tank to run dry. On propane, it runs as long as the tank holds out, and you can have the tank refilled. For a multi-day outage, like the ones Atlanta saw after Hurricane Helene or in recent winter storms, that steady fuel supply is the main reason families choose a generator.

Side by side

• Runs the whole house, A/C and heat included: generator, easily. Battery, only with enough batteries and careful planning.
• Long outages: generator, as long as fuel flows. Battery, until it runs down or the sun recharges it.
• Noise: battery is silent. A generator makes some noise when it runs (we cover that in how loud is a standby generator).
• Fuel: generator needs natural gas or propane. Battery needs nothing but electricity.
• Solar: battery pairs with solar to store your own power every day. A generator only runs when the power is out (plus a short weekly self-test).
• Upkeep: a generator needs yearly maintenance, which our sister company, Southern Power Experts, handles. A battery needs very little.

So which should you choose?

• You want to forget the outage happened, even for days: a standby generator.
• You already have solar and mostly want short outages covered: a battery may make sense.
• You're not sure what your home needs: that's what the free site visit is for.

We install Generac home standby generators, so we'll tell you honestly whether a generator is the right fit for your home. If it isn't, we'll say so.

Sources: Tesla, How Powerwall works; Generac support, run time.

Questions

Can a home battery run my central air?

Sometimes, but A/C is one of the biggest loads in an Atlanta home, so it drains a battery fast. A standby generator sized for your A/C can run it for the whole outage.

Is a generator or a battery cheaper?

It depends on your home, how much you want covered and, for batteries, how many you'd need. We don't post prices because every home is different. A free site visit gets you a written estimate for a generator.