A Generac whole-house generator costs $2,000 to $8,000 for the unit alone on the air-cooled Guardian line, and $7,000 to $20,000 total once you add the automatic transfer switch, electrical work, gas line, concrete pad, permits and labor, based on Generac’s published lineup and installer pricing checked September 2026. Liquid-cooled Protector Series units for larger homes push the unit price itself past $8,000 before installation even starts. Where you land in that range depends mostly on kW size and how far the generator sits from your gas meter and electrical panel.
Generac generator cost by kW size
Generac’s residential lineup splits into two families. The Guardian Series is air-cooled and covers 10 kW to 26 kW, enough for most single-family homes running a well pump, refrigerator, furnace blower and some lighting and outlets on generator power. The Protector Series is liquid-cooled and starts around 25 kW, running up to 80 kW for very large homes or light commercial use. List prices for the unit only, checked September 2026:
| Series | Size | Cooling | Typical unit price |
|---|---|---|---|
| Guardian | 10 kW | Air-cooled | $2,000–$3,200 |
| Guardian | 14 kW | Air-cooled | $2,800–$4,000 |
| Guardian | 18 kW | Air-cooled | $3,200–$4,800 |
| Guardian | 22 kW | Air-cooled | $3,500–$5,500 |
| Guardian | 24 kW | Air-cooled | $4,000–$6,000 |
| Guardian | 26 kW | Air-cooled | $4,500–$6,500 |
| Protector | 25 kW | Liquid-cooled | $8,000–$12,000 |
| Protector | 48 kW | Liquid-cooled | $14,000–$20,000 |
| Protector | 60–80 kW | Liquid-cooled | $20,000–$30,000+ |
The 22 kW Guardian is the most-installed size nationally because it covers a typical 2,000 to 3,000 square foot home’s essentials without the load-management gear smaller units need. Some retailers bundle a 22 kW or 24 kW unit with its transfer switch and wifi monitoring as a single SKU priced near $7,400–$7,800, which is why you will see that unit alone quoted both around $3,500 and near $7,500 depending on what is included.
What drives total installed cost
The unit itself is typically 40 to 50 percent of the total bill. The rest is site work, and every home differs on how much of it is needed:
| Cost item | Typical range |
|---|---|
| Generator unit (7–26 kW Guardian) | $2,000–$8,000 |
| Automatic transfer switch, installed | $1,800–$5,500 |
| Concrete or composite pad | $300–$1,200 |
| Electrical work (panel tie-in, wiring, load management) | $1,500–$3,000 |
| Gas line installation or extension | $500–$1,500 |
| Permits | $80–$500 |
| Installer labor beyond the above | $1,000–$2,000 |
| Typical total, installed | $7,000–$20,000 |
Add the low end of every line and the total is about $7,180; add the high end and it is about $22,200, which brackets the $7,000–$20,000 range installers quote nationally. The single number reported most often for a 22 kW Guardian, fully installed, is $11,000–$14,000. Distance drives most of the spread: a gas line trenched 40 feet from the meter, or a panel that needs a full upgrade before the transfer switch goes in, adds thousands that a straightforward install never sees.
Size the transfer switch to the panel, not just to the generator. A 200-amp transfer switch is rated for 200A x 240V = 48,000W, but its continuous load limit is 80 percent of that rating, or 38,400W, which is one reason installers rarely spec anything smaller for a whole-house switch even on a 22 kW generator that only produces about 22,000W. A load-management module lets a smaller generator run a bigger panel safely by cycling high-draw circuits like a central air conditioner or an EV charger, and it typically adds $300–$800 to the electrical line item rather than requiring a larger, pricier generator.
Permits, inspections and the pad
Most jurisdictions require an electrical permit and a mechanical or gas permit for a standby generator, plus an inspection before it can be switched over; budget $80–$500 total and expect the installer to pull them as part of the job. Generac specifies setback distances from windows, doors and property lines that vary by model, so the pad location has to clear those before it is poured. A standard poured concrete pad for a 10–26 kW Guardian runs $300–$600; composite pads cost more but skip the concrete cure time and let installers finish in a single visit.
Annual maintenance cost
Generac recommends an annual, or twice-yearly in areas with hard winters, service visit: oil and filter change, battery check, and a load test under simulated power-loss conditions. A single visit from an independent installer runs $170–$450; Generac dealer maintenance plans bundling two visits a year with priority emergency scheduling run $200–$600 a year. Over a 10-year service life that is roughly $2,000–$4,500 on top of the installed price, before counting fuel burned during actual outages. See our generator maintenance guide for what each visit covers and how to space them on propane versus natural gas.
A worked example
A homeowner installing a 22 kW Guardian with a new 200-amp transfer switch, a 20-foot gas line run, a poured pad and a straightforward panel tie-in might see: unit $5,500, transfer switch installed $3,000, pad $450, electrical $2,250, gas line $1,000, permits $350, remaining labor $1,500, for a total near $14,050. That sits at the high end of the commonly quoted $11,000–$14,000 range for that size, which tracks: shorter gas runs and simpler panels bring it closer to $11,000. Add a $350-a-year maintenance plan and the 10-year cost of ownership lands around $17,500–$18,000, not counting fuel burned during outages.
The battery backup alternative
A standby generator burns natural gas or propane and needs the site work above; a home battery or large power station needs no gas line and no pad, gets wired to the panel by an electrician, and produces no exhaust, which is why it can sit in a garage or basement a Generac never can. For roughly what a 22 kW Generac install costs, the money buys meaningfully less runtime: 16 kWh Haven Home Backup stores 16,000 Wh for $10,999, the largest single home battery in our home battery backup lineup, while the UL 9540-certified EcoFlow DELTA Pro Ultra Whole-Home Backup Power (UL 9540 Certificated) holds 6,000 Wh for $3,799 and is built to stack extra battery modules as budget allows. Smaller whole-home units like Jackery HomePower 3600 Plus (3,584 Wh, $1,899) and Mango Power E Home Backup and Portable Power Station (3,533 Wh, $1,299) cover a refrigerator, some lighting and internet gear through a multi-hour outage but not a well pump and central air together for days the way a whole-house generator can. The honest trade-off: a generator refuels indefinitely and covers the whole house; a battery is capped by its capacity but needs no fuel, no annual service call and no permit. Our whole-house battery cost breakdown and power station vs. generator comparison walk through which one fits a given outage pattern, and our power station sizing guide covers matching capacity to actual circuits.
Never run a Generac or any fuel-burning generator indoors, in a garage, or near an air intake or window; it produces carbon monoxide that can be fatal within minutes. Panel connections and transfer switch wiring should always be done by a licensed electrician, and back-feeding a panel through a dryer outlet without a transfer switch is illegal in most jurisdictions and can kill utility line workers.
Frequently asked questions
How much does a 22 kW Generac generator cost installed?
Typically $11,000–$14,000 fully installed as of September 2026, with the unit itself running $3,500–$5,500 and the rest going to the transfer switch, electrical work, gas line, pad, permits and labor. Simpler sites land near the bottom; long gas or wire runs push it higher.
Does the transfer switch cost come with the generator?
Sometimes. Some Generac bundles list a generator with its matching transfer switch as one SKU; standalone units do not include one, and either way, physically installing the switch, typically $1,800–$5,500 fully installed, is a separate line item.
How much does Generac maintenance cost per year?
A single annual service visit runs $170–$450; a dealer maintenance plan with two visits a year and priority scheduling runs $200–$600 a year, which adds up to roughly $2,000–$4,500 over a 10-year service life.
Is a home battery cheaper than a Generac generator?
The equipment can cost less, but capacity is capped. A single large power station or home battery can cost less than a Generac install and needs no gas line, pad or permit, but it runs out of stored energy in hours unless paired with solar, while a fueled generator keeps running as long as gas or propane keeps arriving.
Can I install a Generac generator myself to save money?
The pad can be a do-it-yourself job, but the gas line and the electrical panel connection need a licensed gas fitter and a licensed electrician in nearly every jurisdiction, both for code compliance and because a miswired transfer switch can back-feed the utility grid and endanger line workers.