A Generac generator costs anywhere from about $500 for a small portable to $8,000 or more for the largest air-cooled Guardian home standby unit — but for a standby machine, the price of the box is usually less than half of what you will actually pay. Once the transfer switch, gas line, electrical work, pad and permits are added, a typical whole-house Generac lands between $11,000 and $18,000 installed, and the spread between two quotes for the same model is mostly site work, not margin.
This breaks down where that money goes, what each size class costs, what it costs to keep one running, and where the realistic savings are. Every figure here is a range: generator pricing varies considerably by region, by dealer, and by how far your electrical panel and gas meter sit from where the unit can legally go. Use these numbers to judge whether a quote is reasonable, not as a substitute for one. If you have not yet decided between portable, inverter and standby, start with our guide to the best home generator for power outages, which covers sizing and the three categories in detail.
Unit Prices by Size
Generac sells three quite different things under one brand name: portable generators you wheel out and plug in, Guardian-series air-cooled home standby units that start automatically, and liquid-cooled and battery systems at the top end. The unit prices below are typical retail and dealer ranges for the equipment alone, before any installation.
| Category | Output | Unit price (typical range) | What it covers |
|---|---|---|---|
| Inverter portable | 2,000–3,500 W | $500 – $1,300 | Fridge, lights, phones, router |
| Conventional portable | 3,500–8,000 W | $600 – $1,500 | Essentials plus a well or sump pump |
| Large portable | 8,000–17,500 W | $1,300 – $3,500 | Most of a house, with a transfer switch |
| Guardian 10 kW standby | 10 kW | $3,000 – $4,000 | Essential circuits, small home |
| Guardian 14 kW standby | 14 kW | $4,300 – $5,500 | Essentials plus one small AC |
| Guardian 18 kW standby | 18 kW | $5,000 – $6,300 | Mid-size home, managed whole-house |
| Guardian 22 kW standby | 22 kW | $5,800 – $7,000 | Most homes up to ~3,000 sq ft |
| Guardian 24–26 kW standby | 24–26 kW | $6,500 – $8,500 | Larger homes, two AC systems |
| Liquid-cooled standby | 22–60+ kW | $12,000 – $30,000+ | Very large homes, heavy electric loads |
Two details matter when comparing unit prices. First, check whether the price includes an automatic transfer switch. Generac sells many Guardian models both as a bare generator and as a package with a 200-amp whole-house transfer switch, and the difference is several hundred dollars to over a thousand. Second, the standby price does not include a starting battery, which is usually bought separately for $50–$150.
Where PWRcell Fits
Generac's PWRcell line is a different product altogether: a lithium battery storage system, usually paired with solar panels, that powers the house silently from stored energy rather than burning fuel. Systems are modular, and installed costs typically run well into five figures — commonly $15,000–$30,000 or more depending on capacity and whether solar is part of the job. A battery system avoids fuel costs, noise and emissions entirely, but it runs out. Without solar to recharge it, a battery will carry essential loads through a typical overnight outage, not a week-long one. For long outages in cold or hot weather, a fuelled standby generator is still the cheaper way to buy runtime; a battery is the better buy where outages are short and frequent, or where noise rules and HOA restrictions make a generator difficult.
Installation Cost Breakdown
Installation is where quotes diverge. A standby generator is an electrical, gas and sometimes civil job in one, and each part is priced on your specific property.
| Line item | Typical range | What pushes it higher |
|---|---|---|
| Electrical labour and materials | $1,500 – $4,000 | Long wire run, panel upgrades, meter relocation |
| Automatic transfer switch (200A whole-house) | $500 – $1,500 | Service-entrance rating, outdoor enclosure |
| Automatic transfer switch (400A) | $1,500 – $3,000+ | Large homes with 320–400A service |
| Essential-circuit transfer switch (50–100A) | $300 – $800 | Number of circuits moved to the sub-panel |
| Load management modules | $200 – $500 each | Number of large appliances managed |
| Natural gas line run | $500 – $2,500 | Distance from meter, trenching, meter upgrade |
| Propane tank (if no natural gas) | $1,500 – $4,000+ | Tank size, buried vs. above-ground, owned vs. leased |
| Pad and site prep | $100 – $800 | Poured concrete vs. gravel, sloped ground |
| Permits and inspections | $100 – $500+ | Jurisdiction, separate electrical and gas permits |
| Starting battery, cold-weather kit | $100 – $450 | Climate; cold kits matter below freezing |
1. The Transfer Switch: Whole-House or Essential Circuits
The transfer switch is what disconnects your house from the grid and connects it to the generator, and it is the single decision that most shapes the rest of the job.
A whole-house switch sits between the utility meter and your main panel, usually rated 200 amps to match standard residential service. Everything in the house becomes available to the generator. It costs more as a part, but the wiring is often simpler, because nothing has to be moved. The catch is that a whole-house switch only works if the generator can handle whatever the household turns on — which is why it is usually paired with load management modules that shed large appliances such as a second AC unit, an electric dryer or a water heater when the generator nears capacity.
An essential-circuit switch feeds a small sub-panel holding only the circuits you choose: fridge, freezer, furnace blower, well pump, sump pump, a few lighting and outlet circuits. The switch itself is cheaper, but an electrician has to physically move those circuits from the main panel, which adds labour. Its real saving is that it lets a 10 or 14 kW generator do the job instead of a 22 kW one, which can take $1,500–$3,000 off the unit price and reduces fuel use during every outage.
For a home with 320 or 400-amp service, a whole-house switch is a substantially larger part, and some installers will instead recommend two switches or a managed configuration. Ask for both options priced side by side.
2. The Gas Line
Natural gas runs from the meter to the generator, and the cost is mostly distance and route. A short run along the outside of the house can be a few hundred dollars. A long run that requires trenching across a yard, boring under a walkway or coming off a different side of the house can reach $2,000–$2,500 or more.
The less obvious cost is the meter. A 22 kW generator at full load draws a lot of gas, and some existing residential meters and regulators were sized only for a furnace, water heater and range. If the installer's load calculation shows the meter is undersized, the utility may need to upgrade it. Some utilities do this at no charge; others bill for it, and the scheduling alone can delay the job by weeks. Ask early.
3. Concrete Pad or Gravel
Air-cooled Guardian units ship with a composite mounting pad designed to sit on a compacted gravel base, which is usually all that is needed and costs $100–$300 to prepare. A poured concrete pad adds $300–$800 and is worth it on soft or sloped ground, where local code calls for one, or where you simply want the unit to stay level for twenty years. Placement is set by clearance rules — distance from windows, doors, vents and the property line — so the cheapest spot is not always available, and a spot further from the panel and meter means longer runs.
4. Electrical Work
The largest single labour line. It covers wiring from the generator to the transfer switch, connecting the switch at the service entrance, any load management wiring, and the control wiring that tells the generator when the grid has dropped. Expect $1,500–$4,000 on a straightforward install. Older panels without space, aluminium service conductors, or a meter that has to move push it higher. If the panel needs replacing anyway, that is a separate $1,500–$4,000 job that some installers bundle in.
5. Permits and Inspections
Almost every jurisdiction requires an electrical permit and many require a separate gas or mechanical permit, typically $100–$500 combined, occasionally more in large cities. A legitimate installer pulls them as part of the quote. A quote that is unusually cheap because it skips permits is not a saving: unpermitted electrical work can cause problems with insurance claims and home sales.
Total Installed Cost
Putting the unit and installation together gives the number that actually matters. These ranges assume natural gas already at the house and a reasonably straightforward site; propane and difficult sites push toward the top or beyond.
| Setup | Unit | Installation | Total installed |
|---|---|---|---|
| Portable + interlock kit and inlet | $600 – $2,500 | $500 – $1,200 | $1,100 – $3,700 |
| Portable + manual transfer switch | $600 – $2,500 | $700 – $1,500 | $1,300 – $4,000 |
| Guardian 10 kW, essential circuits | $3,000 – $4,000 | $4,000 – $7,000 | $7,000 – $11,000 |
| Guardian 14 kW, essential circuits | $4,300 – $5,500 | $4,200 – $7,500 | $8,500 – $13,000 |
| Guardian 18 kW, managed whole-house | $5,000 – $6,300 | $5,000 – $8,700 | $10,000 – $15,000 |
| Guardian 22 kW, whole-house | $5,800 – $7,000 | $5,200 – $11,000 | $11,000 – $18,000 |
| Guardian 24–26 kW, whole-house | $6,500 – $8,500 | $6,500 – $13,500 | $13,000 – $22,000 |
| Liquid-cooled 30–60 kW | $12,000 – $30,000 | $8,000 – $15,000+ | $20,000 – $45,000+ |
The 22 kW Guardian is the most commonly installed size because it is the smallest unit that comfortably runs a typical house with one central air conditioner without careful load juggling. It is also the size at which the unit price and the installation cost are roughly equal — a useful sanity check when a quote arrives.
Regional variation is real. Areas with frequent hurricanes, ice storms or wildfire-related shutoffs tend to have more installers and more competitive pricing but also longer waits after a major event, when demand spikes. Urban areas with high electrician labour rates push the installation share up. The cheapest time to buy is rarely the week after a long outage.
Natural Gas or Propane?
Guardian units run on either natural gas or liquid propane, and which one you use affects both the installation cost and every outage that follows.
Natural gas is the cheaper option almost everywhere it is available. There is no tank to buy, no deliveries to schedule, and supply is effectively unlimited for as long as the utility keeps pressure up — which it generally does through electrical outages. Installation cost is the gas line run and possibly a meter upgrade. The generator produces slightly less power on natural gas than on propane, so check the unit's rating for the fuel you will use.
Propane is the answer for homes without a gas main. A 500-gallon tank, the common size for a 22 kW generator, typically costs $1,500–$3,500 to buy and set above ground, more if buried. Many households lease a tank from the propane supplier instead, usually for a modest annual fee, in exchange for buying fuel only from that supplier. Tanks are filled to about 80% of capacity for safety, so a 500-gallon tank holds roughly 400 usable gallons.
If you already have a propane tank for heating or cooking, it may be possible to run the generator from it, but only if the tank is large enough to supply both at once in cold weather. A 120 or 250-gallon tank that is fine for a furnace is usually too small to run a 22 kW generator through a multi-day outage as well.
Ongoing Costs
Annual Maintenance
Generac recommends regular oil and filter changes, air filter and spark plug replacement, and a general inspection on a schedule set out in each model's manual, typically annually or after a set number of run hours, whichever comes first. A dealer maintenance visit usually costs $200–$400, and many dealers sell multi-year maintenance plans. Doing it yourself with a maintenance kit costs perhaps $30–$80 in parts, though some owners prefer the dealer service so there is a record if a warranty claim arises. The starting battery wears out every three to five years and costs $100–$200 to replace; a dead battery is one of the most common reasons a standby generator fails to start when it is needed.
The Weekly Exercise Cycle
Standby generators start themselves on a schedule — typically weekly, for a few minutes at reduced speed on current Guardian models — to keep the engine lubricated and confirm everything works. The fuel used is small: a few dollars a month on natural gas, slightly more on propane. The battery charger and any cold-weather heaters draw a small amount of electricity continuously. Together, the idle running costs are modest, usually well under $100 a year.
Fuel During an Outage
This is the cost most people underestimate. Fuel consumption depends on the load, not the generator size, so a 22 kW unit lightly loaded uses far less than one running near capacity.
| Generator (approx. half load) | Natural gas per day | Propane per day |
|---|---|---|
| 10–14 kW standby | $30 – $70 | $90 – $170 |
| 18–22 kW standby | $50 – $120 | $150 – $250 |
| 24–26 kW standby | $60 – $140 | $180 – $300 |
| Portable 7–8 kW (gasoline) | $40 – $80 at typical loads, plus refuelling every 8–12 hours | |
These are rough figures based on typical residential gas and propane prices, which vary considerably by region and season. As a rule of thumb, a 22 kW unit at half load burns roughly 3 gallons of propane an hour, so a full 500-gallon tank lasts somewhere around five to seven days of continuous running. That is the reason propane households should keep the tank topped up ahead of storm season — delivery trucks are scarce in the middle of a regional outage.
Warranty
Guardian air-cooled units carry a five-year limited warranty as standard. Dealers typically offer paid extensions to seven or ten years for roughly $500–$1,500. Whether that is worth it depends on how heavily the unit is likely to run; registering the unit and keeping service records matters more than the extension itself.
What Size Your Home Needs
Oversizing wastes money twice — once on the unit, again on fuel at every outage — while undersizing means the generator trips or the load manager sheds the appliances you wanted. A licensed installer should do a load calculation, but these guidelines show where most homes land.
| Home and loads | Typical size | Switch type |
|---|---|---|
| Small home, gas heat, essentials only | 10 kW | Essential-circuit |
| Up to ~2,000 sq ft, essentials plus one small AC | 14 kW | Essential or managed |
| 2,000–2,500 sq ft, one central AC | 18 kW | Whole-house with load management |
| 2,500–3,500 sq ft, one or two AC units | 22 kW | Whole-house with load management |
| 3,500+ sq ft, two AC units, electric range or well | 24–26 kW | Whole-house, sometimes 400A |
| Electric heat, heat pumps with strip heat, pools | Load calculation essential | Often liquid-cooled |
Square footage is a proxy, not a rule. What really sizes a generator is the largest motor loads — central air, a well pump, a heat pump — and the starting surge they draw. Electric resistance heat is the load that breaks the pattern: a home heated by baseboard or furnace strip heat can need far more capacity than its size suggests. A soft-start kit on the air conditioner, typically a few hundred dollars installed, reduces that starting surge and can sometimes allow a size smaller generator.
Do not forget the loads that matter most in a storm. A basement sump pump and a basement dehumidifier are small by generator standards but are often the reason the generator was bought, and they belong on any essential-circuit list. If your basement takes water every time the power goes out, fixing the water problem itself — see how to waterproof basement walls — is worth doing alongside.
Ways to Save
Portable Generator Plus Interlock
The largest saving by far. A conventional or dual-fuel portable in the 7,000–9,500 watt range plus a panel interlock kit and an outdoor power inlet gives you most of what a standby unit does — furnace, fridge, well or sump pump, lights, internet — for roughly $1,500–$3,500 installed instead of $11,000 or more.
An interlock is a mechanical plate on your main panel that makes it physically impossible to have the main breaker and the generator breaker on at the same time, which prevents backfeeding power into the utility lines. The kit itself is inexpensive; an electrician installing it with an inlet box typically charges $500–$1,200 all in. Check that an interlock is permitted in your area and listed for your specific panel. A manual transfer switch does the same job with pre-selected circuits for a little more.
The trade-offs are real. A portable does not start itself, needs refuelling every eight to twelve hours on gasoline, has to be run at a safe distance from the house — never in a garage, even with the door open — and someone has to be home to deal with it. If you travel, have a medical need for uninterrupted power, or live where outages often last days, a standby generator earns its premium. If outages are a few times a year for a few hours, a portable and interlock is the sensible buy. Our home generator guide covers portable sizing and safe connection in full.
Size Down With Load Management
Load management modules let a smaller generator cover a whole house by temporarily shedding large appliances. Stepping from a 22 kW to an 18 kW unit with two modules can save more than the modules cost — and saves fuel at every outage.
Choose the Site Carefully
The shortest legal distance between the generator, the gas meter and the electrical panel is usually the cheapest installation. Ask the installer to price two locations if more than one is possible; the difference can easily be $1,000.
Get Three Quotes and Time the Purchase
Installed prices for the same model vary widely between dealers. Generac and its dealers also run periodic promotions, such as rebates or bundled extended warranties, typically outside the peak storm season. Late autumn and winter, outside hurricane season, are usually the easiest time to get scheduled and negotiate.
Check Local Incentives
Fuel-burning standby generators generally do not qualify for federal tax credits. Battery storage systems such as PWRcell did qualify for the federal residential clean energy credit, but that credit ended for systems placed in service after 2025, so a 2026 purchase should not count on it. Some states, utilities and insurers offer their own incentives or premium discounts for backup power, particularly where outages are frequent. They change often, so ask your installer and your insurer directly.
Generac vs. Kohler, Briggs and Champion
Generac is the largest seller of home standby generators in the US, which mostly means one practical advantage: dealer density. More installers and more parts availability usually mean faster service after a storm. It does not automatically mean the lowest price.
| Brand | Typical 20–22 kW unit price | Positioning |
|---|---|---|
| Generac Guardian | $5,800 – $7,000 | Market leader; widest dealer and service network |
| Kohler | $6,000 – $8,000 | Often priced higher; strong reputation for build and power quality |
| Briggs & Stratton | $5,500 – $7,000 | Competitive pricing; smaller dealer network in many areas |
| Champion | $5,000 – $6,500 | Usually the lowest unit price; long standard warranty |
Kohler, whose energy business now operates as Rehlko, tends to sit at the premium end and is popular with installers who favour its engine design and clean power output. Briggs & Stratton standby units are usually priced close to Generac and sometimes come bundled with load management. Champion generally undercuts all three on the unit and offers a ten-year limited warranty on its home standby line, though its installer network is thinner.
The important point is that installation cost is roughly the same whichever brand you choose. A $1,000 difference in unit price is meaningful, but on a $14,000 project, the quality of the local installer and the availability of service when the unit will not start matter more. Before choosing a brand, find out which brands the good installers near you actually service.
Is It Worth It? ROI and Resale
A standby generator is insurance, and like insurance, it rarely pays for itself in strictly financial terms. The question is what an outage costs you.
Direct losses avoided. A full fridge and freezer of food is commonly $300–$1,000. A flooded basement because the sump pump stopped can run into the thousands or tens of thousands, and is frequently excluded or capped under standard homeowners policies without a specific endorsement. Frozen and burst pipes in a winter outage are similar. A hotel for a family for several nights is another few hundred dollars. For a remote worker or home business, lost income can dwarf all of these.
Resale value. National cost-versus-value surveys have generally found that a backup generator recovers around half its cost at sale — comparable to many other home improvements but not a profit. In areas with frequent, long outages, buyers notice a permanently installed standby generator, and it can help a house sell faster. In areas with reliable power, it is a pleasant extra rather than a value driver.
Lifespan. A well-maintained air-cooled standby unit commonly lasts 15 to 25 years or around 2,000–3,000 run hours, whichever comes first. Spread over twenty years, a $14,000 installation is around $700 a year plus maintenance and fuel.
The case is strongest if your area loses power for a day or more at least once a year, if you rely on a well or sump pump, if someone in the house depends on powered medical equipment, or if you are often away. Where outages are rare and short, a portable and interlock gives better value, alongside sensible storm prep such as clean gutters — our gutter guard guide covers that — and a wet/dry shop vac for the water that gets in anyway.
The Short Version
Budget $11,000–$18,000 for a typical whole-house Generac Guardian 22 kW installed on natural gas — roughly half for the unit and transfer switch, half for installation. Add $1,500–$4,000 if you need a propane tank.
Budget $7,000–$13,000 for a 10 or 14 kW unit wired to essential circuits, which covers what most households actually need in an outage.
Budget $1,500–$3,500 for a portable generator plus a professionally installed interlock or transfer switch if outages are occasional and someone is usually home.
Then add $200–$400 a year for maintenance and a realistic fuel figure for a multi-day outage, and get at least three itemised quotes before signing. The model number is the easy part; the site work is where the money and the mistakes are.
Frequently Asked Questions
For the most popular size, the 22 kW Guardian, expect roughly $11,000–$18,000 installed on natural gas, with the unit itself around $5,800–$7,000 and installation making up the rest. Smaller 10–14 kW units wired to essential circuits typically run $7,000–$13,000 installed, and 24–26 kW units $13,000–$22,000. The installation share covers the transfer switch, electrical work, gas line, pad, permits and start-up. Propane adds a tank, typically $1,500–$3,500 for a 500-gallon unit. Prices vary meaningfully by region and dealer, and site conditions such as distance from the gas meter and panel move the total more than the choice of model does.
Typically $5,800–$7,000 for the unit, depending on the dealer, region and whether a 200-amp automatic transfer switch is bundled in the package. Check that detail carefully, because the transfer switch alone is worth several hundred dollars to over a thousand. The starting battery is usually extra at $50–$150. Buying the unit alone rarely saves money: installation is specialist electrical and gas work that requires permits, and Generac's warranty terms generally expect installation by a qualified installer.
Because it is three trades in one job. An electrician installs the transfer switch at the service entrance and runs wiring from the generator; a gas fitter runs a line from the meter, sometimes requiring a utility meter upgrade; and the site needs a level, compliant pad set at the required clearances from windows, doors and vents. Permits and inspections add another layer. Electrical work alone is typically $1,500–$4,000, the transfer switch $500–$1,500 for 200 amps, and the gas line $500–$2,500 depending on distance. Long runs, older panels and difficult sites push all of these up.
It depends on the load and fuel. As a rough guide, an 18–22 kW unit at around half load costs approximately $50–$120 a day on natural gas and $150–$250 a day on propane at typical residential prices. A 22 kW unit at half load burns roughly 3 gallons of propane an hour, so a full 500-gallon tank lasts about five to seven days of continuous running. Smaller units and lighter loads cost less. Outside outages, the weekly exercise cycle and battery charger cost very little — usually well under $100 a year.
A dealer service visit typically costs $200–$400 and covers oil and filter change, air filter, spark plugs where due, battery test and a general inspection. Do-it-yourself maintenance kits cost roughly $30–$80 in parts. Budget an additional $100–$200 every three to five years for a replacement starting battery, which is one of the most common causes of a failed start. Keep records of every service, because they matter if you need to make a warranty claim.
Most homes of 2,500–3,500 square feet with one central air conditioner end up with a 22 kW unit on a whole-house transfer switch with load management. A small home with gas heat that only needs essentials can use a 10 kW unit; adding one small AC suggests 14 kW. Larger homes with two AC systems, electric cooking or a well pump often need 24–26 kW. Electric resistance heat changes everything and needs a proper load calculation. Square footage is only a proxy: what really sizes a generator is your largest motor loads and their starting surge.
For many households, yes. A 7,000–9,500 watt portable plus an interlock kit and power inlet installed by an electrician costs roughly $1,500–$3,500 total and can run a furnace, fridge, sump or well pump, lights and internet. The interlock prevents dangerous backfeeding by making it impossible to turn on the main and generator breakers together. The trade-offs are that someone must be home to start, refuel and position the generator at a safe distance outdoors, and it will not cover central air or the whole house. If outages are occasional and short, it is the better value.
Somewhat. National cost-versus-value surveys have generally found that a backup generator recovers around half its cost at resale. In regions with frequent long outages from hurricanes, ice storms or utility shutoffs, a permanently installed standby generator is a meaningful selling point and can help a home sell faster. In areas with reliable power, buyers treat it as a nice extra rather than paying full value for it. The stronger financial case is usually the losses it prevents, such as a flooded basement when the sump pump stops, spoiled food and frozen pipes.