A whole-home standby generator sits permanently outside your house and runs on natural gas or propane. When it senses a power outage, an automatic transfer switch safely disconnects your home from the grid and starts the generator, restoring power in about 10–30 seconds — automatically, even if you are not home.
The main parts of a standby generator system
- The generator unit — a weatherproof unit outside your home that produces electricity.
- The automatic transfer switch (ATS) — the “brain” that detects the outage and switches your home between grid and generator power.
- The fuel supply — a connection to your natural gas line or a propane tank, so it never needs hand-refueling.
What happens during a power outage, step by step
- Detect: The ATS constantly monitors utility power and senses the moment it drops.
- Transfer: It disconnects your home from the grid (protecting utility crews) and signals the generator to start.
- Power: The generator starts and restores electricity — usually within 10–30 seconds.
- Monitor: It runs for as long as the outage lasts, adjusting output to your home’s demand.
- Switch back: When utility power returns, the ATS reconnects you to the grid and shuts the generator down.
How is this different from a portable generator?
A portable generator must be rolled out, started by hand, and refueled with gasoline, powering only a few devices through extension cords. A standby unit is permanently installed, powers your whole home through the electrical panel, and runs automatically. See our full standby vs. portable generator comparison.
The weekly self-test
Standby generators run a brief self-test once a week to confirm they are ready, so it is normal to hear it cycle for a few minutes. Pairing that with annual service keeps the system dependable — see our Generac maintenance schedule.
Frequently asked questions
How fast does a standby generator turn on?
Usually within 10–30 seconds of an outage — often just a brief flicker.
Does a standby generator run on gas or electricity?
It runs on natural gas or propane and produces electricity. It does not need the grid to operate.
Does it work when I am not home?
Yes. The entire process is automatic, so your home stays powered whether you are there or away.
Thinking about whole-home backup? Book a free consultation and we will walk your home and recommend the right system. Proudly serving Houston and Montgomery County.