Standby Generators: The Real Cost to Install and Run (2024)

TL;DR: A whole-house standby generator sized for an average home (16-22kW) costs $10,000-$20,000 fully installed, including the transfer switch, gas line, and concrete pad. Budget another $200-$500 a year for fuel testing, oil changes, and a service contract, plus $150-$250 for annual professional inspection if you don't do it yourself.

_Last reviewed: July 2026 · 8 min read_

The generator itself is never the real number. Homeowners see a $3,500 sticker price on a 22kW unit at the hardware store, then get a quote for $16,000 once the electrician, gas company, and permit office are done with it. Here's what actually drives that gap and where you can shave costs without cutting corners on safety.

Okoniq Property Hub lets you log your generator's install date, warranty terms, and every service visit in one place, so you're never guessing when the next oil change or battery swap is due.

How much does a standby generator actually cost installed?

A fully installed standby generator for a typical single-family home runs $10,000 to $20,000, with the generator unit itself being only 30-40% of that total. A 16kW unit (covers essentials: fridge, well pump, a few circuits) starts around $3,000-$4,500 for the machine, while a 22kW whole-house unit runs $4,500-$6,500.

The rest goes to labor and materials most people don't budget for: a concrete or composite pad ($200-$600), the automatic transfer switch ($800-$2,000 for the part alone), electrical work to tie into your panel ($1,500-$3,000), and a gas line extension from your meter to the unit ($500-$2,000 depending on distance and whether you're on natural gas or propane). If your home still has an older 100-amp panel, you may need a panel upgrade before a generator install even makes sense. Our guide on 100 vs 200 amp service explains how to check what you're working with before you call an electrician.

Permits add $100-$500 depending on your city, and many jurisdictions require an inspection before the unit can be turned on.

What does it cost to run a standby generator every year?

Annual operating costs for a standby generator run $200-$500, even if you never lose power. That number covers the weekly self-test cycle (most units run 5-20 minutes automatically), an annual oil and filter change ($75-$150 if you hire it out), air filter replacement, and battery checks.

If you're on natural gas, the self-tests and any actual outage use cost pennies to a few dollars per hour, since gas is metered and cheap relative to propane. Propane owners should budget more: a 22kW unit burns roughly 2-3 gallons per hour at full load, and propane runs $2.50-$4 a gallon depending on region and season, so a multi-day outage can add up fast.

Most manufacturers recommend a full service every 100-200 hours of runtime or once a year, whichever comes first. Skipping this is the single biggest reason generators fail during the outage they were bought for, usually from stale fuel, a dead battery, or a clogged air filter that nobody caught during eight months of sitting idle.

Is a standby generator worth it compared to a portable one?

A standby generator is worth the extra cost if you lose power more than once or twice a year, have medical equipment at home, or live somewhere with harsh winters or hurricane risk. A portable generator costs far less upfront but comes with real tradeoffs in convenience and safety.

| | Standby Generator | Portable Generator | |---|---|---| | Upfront cost | $10,000-$20,000 installed | $500-$2,500 | | Starts automatically | Yes, within seconds | No, manual setup required | | Fuel source | Natural gas or propane, continuous | Gasoline, needs refueling every 8-12 hrs | | Powers whole house | Yes (with right sizing) | Usually just essentials | | Annual upkeep | $200-$500 | Minimal, but fuel stabilizer needed |

Portable units also require you to run a heavy-gauge extension cord or a manual transfer switch, and improper hookups are a leading cause of backfeed accidents that can electrocute utility workers. If your home still has ungrounded outlets from an older electrical system, that's worth fixing regardless of which generator route you take. Our post on upgrading 2-prong outlets safely covers what a proper ground looks like.

How do you size a generator correctly so you don't overpay or underpower your house?

Sizing comes down to running watts, not just square footage. A licensed electrician does a load calculation based on your actual appliances: central AC compressor, well pump, furnace blower, refrigerator, and any high-draw items like an electric range or EV charger.

Most homes land in the 16-22kW range. Going bigger "just in case" adds $1,500-$3,000 to your install cost for capacity you'll rarely use, while undersizing means the unit trips or can't start your AC compressor during a real outage. If your panel is older or was never updated for modern loads, that's the same conversation as the amp service question above, and it's worth resolving before the generator quote, not after.

What should you check before signing a generator contract?

Get at least two quotes and confirm three things in writing: who pulls the electrical and gas permits, whether the transfer switch is service-rated for your panel, and what the warranty covers versus what's a separate service plan. Many installers bundle a 5-10 year warranty on the generator but only 1 year on labor, which matters if something fails in year three.

FAQ

How long does a standby generator last?

Most standby generators last 20-30 years with regular maintenance, though the transfer switch and battery typically need replacement every 5-10 years.

Do I need a permit to install a standby generator?

Yes, in nearly every US jurisdiction you need an electrical permit and often a separate gas permit, with inspection required before the unit is activated.

Can I install a standby generator myself?

The gas line and electrical transfer switch connections must be done by a licensed electrician and often a licensed gas fitter, so full DIY installation isn't legal or safe in most areas.

How often should a standby generator be serviced?

Once a year or every 100-200 hours of runtime, whichever comes first, covering oil, filters, spark plugs, and a full load test.

What size generator do I need for an average 2,000 sq ft home?

Most 2,000 sq ft homes need 16-22kW to cover HVAC, refrigeration, and essential circuits, but an electrician's load calculation is the only accurate way to confirm your number.

This is educational information, not electrical or financial advice. Get a licensed electrician to size and install your generator, and confirm gas line work with a licensed gas fitter in your state.