Generator shoppers
We're not going to talk you out of backup power. But we are going to talk you out of a generator. Here's why.
First, the honest side-by-side. Then the parts nobody mentions at the store.
Private homeowner program. Not affiliated with CenterPoint, ERCOT, the PUC or any government agency.
Generator vs Powerwall 3
| Feature | Powerwall 3 | Standby generator | Portable gas generator |
|---|---|---|---|
| Starts by itself | Yes, in under a second | Yes, in 10–30 seconds | No |
| Fuel | None | Natural gas or propane | Gas, refill every 8–12 hours |
| Fumes and carbon monoxide | None. It lives in your garage | Exhaust outdoors | Yes. Outdoors only, 20 ft from windows |
| Noise | Silent | Loud | Loud |
| Upkeep | None. Check it in the app | Yearly service and self-tests | Oil, fuel stabilizer, test runs |
| Runs in the rain | Yes | Yes | Not safely |
| Recharges from solar | Yes | No | No |
| Useful on normal days | Yes | No | No |
| Warranty | 10 years | About 5 years | 1–3 years |
To be fair: a generator keeps running as long as it has fuel. One Powerwall 3 stores 13.5 kWh, and your advisor sizes your system to what you want backed up.
Why we'd skip the generator
Fuel, every dayA portable generator running a house burns through gallons of gas a day, and the tank needs refilling every 8 to 12 hours. That means storing gas in the garage before the storm.
Refueling in the middle of the stormAfter Beryl, Houston gas stations had lines of 30 minutes or more, and some ran out. The generator works. The gas station might not. Houston Chronicle, July 2024
Fumes and carbon monoxideA portable has to run outdoors, at least 20 feet from windows and doors, even in the rain. After Beryl, Harris, Fort Bend and Montgomery counties logged more than 100 carbon monoxide poisonings in four days. Houston Public Media, July 12, 2024
NoiseLoud enough that you hear it inside, and so do the neighbors. All night.
UpkeepOil changes, fuel stabilizer, test runs, and for a standby unit, yearly service. Skip it and it may not start when you need it.
It only helps during outagesThe other 360-some days a year it sits there. A Powerwall 3 works every day and can recharge from solar.
When a generator is the right call
- You expect outages that last weeks, not days, and you're set up to store and rotate a lot of fuel.
- You need backup right now and can't wait for an install.
- You already own one and just want something for the occasional short outage.
When a Powerwall 3 is
- You want backup that starts by itself, in under a second, with nobody home.
- You don't want gas in the garage, fumes near the windows or a motor running all night.
- You want something that's useful on normal days too, and works with solar if you add it.
- You want your advisor to size it to what you actually want kept on.
