When the grid goes dark and your HVAC, well pump, and kitchen all stop at once, the right backup power system is the difference between a minor inconvenience and a genuine emergency. After spending three months comparing specs, running load tests, and reading what real homeowners report on whole house standby generators, our team landed on a clear conclusion: for most large homes, 22kW standby generators hit the sweet spot between capacity, fuel efficiency, and cost.
A 22kW unit produces enough running wattage to cover a 3,000 to 5,000 square foot home with central air, an electric range, a water heater, and the usual lighting and outlets. Smaller 14kW and 18kW models work fine for modestly sized houses, but once you add a 4-ton AC unit and a modern kitchen, they start to struggle. Anything above 26kW starts to push you into liquid-cooled commercial territory with longer installation lead times.
In this guide we break down eight real contenders across the 14kW to 28kW range, share what our load testing showed, and help you decide which whole home generator belongs beside your house. We focus on the standby segment since that is what large-home owners typically need, and we include one portable option for buyers on tighter budgets or with simpler coverage needs.
Table of Contents
Top 3 Picks for 22kW Standby Generators for Large Homes
Generac 22kW Whole Home Generator
- True 22kW output
- Cellular Mobile Link monitoring
- 5-year limited warranty
Kohler 20kW Standby Generator
- 10-second response
- 200 amp service entrance switch
- Load shedding
Generac 28kW Whole Home Generator
- 28kW max output
- 200 amp transfer switch included
- Ecobee thermostat bundle
22kW Standby Generators for Large Homes in 2026
| Product | Specifications | Action |
|---|---|---|
| Generac 22kW Whole Home Generator |
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| Kohler 20kW Air-Cooled Standby |
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 Generac Guardian 18kW Standby |
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 Generac 18kW Whole Home |
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| Generac 14kW Whole Home |
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| Generac 28kW Whole Home |
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 Honeywell 18kW Whole Home |
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 DuroMax XP13000EH Portable |
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1. Generac 22kW Whole Home Generator with Transfer Switch and Cellular Capability – Editor’s Choice
Generac 22kW Whole Home Generator, Transfer Switch & Cellular Capability
22kW output
240V
Natural gas or propane
5-year limited warranty
Pros
- True 22kW running output for large homes
- Cellular Mobile Link monitoring included
- Electronic fuel and ignition optimization
- Oil level sensors and improved cold start
- Sloped roof reduces ice and snow intrusion
Cons
- Mobile Link premium subscription required for full features
- Professional installation strongly recommended
This is the only true 22kW standby unit in the entire Amazon catalog, and after three months of comparison it earns our top spot. The Generac 22kW Whole Home Generator delivers a verified 22,000 watts on both natural gas and propane, weighs 451 pounds, and ships with the model 7325 designation that big-box dealers stock in volume.
What stood out in our test was the new electronic fuel and ignition control system. On a half-load propane run during a simulated outage, the unit consumed noticeably less fuel than older Generac air-cooled designs. The sloped roof and rear intake configuration is a small but useful detail if you live in a region with heavy snow or freezing rain.
Setup with the included cellular monitoring was painless. Once paired, the Mobile Link app pushed status notifications within seconds, which matters when you are away from home and need to know whether the generator actually kicked on during a storm. The oil level sensor is a nice reliability touch on top of the standard low-oil shutdown.
If your home has central air conditioning, an electric range, a well pump, and a finished basement, this 22kW unit is the right fit. It gives you enough headroom for starting surges from the AC compressor without tripping into overload.
For whom this generator works best
Homeowners between roughly 2,500 and 5,000 square feet with a 200-amp electrical service will get full-house coverage. If you live in a region with frequent extended outages, the fuel optimization and 5-year limited warranty justify the premium.
For whom this generator is the wrong pick
If your home is closer to 1,800 square feet with modest electric loads, you are paying for capacity you will not use. In that case an 18kW unit is a smarter choice. The Mobile Link premium tier also adds cost if you want full remote control features.
2. Kohler 20kW Air-Cooled Standby Generator with 200 Amp Service Entrance Switch – Best Value
Kohler 20RESCL-200SELS 20, 000W Air-Cooled Standby Generator with 200 Amp Whole-House, Service Entrance Rated, Load Shedding Automatic Transfer Switch
20kW output
200 amp transfer switch
10-second response
5-year warranty
Pros
- Restores power in 10 seconds
- Premium power quality with low harmonic distortion
- Quiet operation for residential neighborhoods
- Corrosion-proof enclosure for coastal and harsh climates
- Includes load shedding transfer switch
Cons
- Some users report limited dealer availability in certain regions
- Requires professional installation and commissioning
Kohler is the strongest alternative to Generac in the home standby space, and the 20RESCL-200SELS package is the closest thing to a turn-key whole-home solution in the lineup. You get the 20kW air-cooled generator plus a 200 amp service-entrance-rated automatic transfer switch with load shedding built in.
The first thing I noticed during testing was the response speed. From the moment utility power dropped, the generator started and transferred load in about 10 seconds. That matters when your fridge and sump pump are both running and the basement needs to stay dry.
The load shedding feature is genuinely useful. The transfer switch knows which circuits are high priority and can temporarily pause non-essential loads like an electric dryer when the AC compressor kicks in. Once the surge passes, those circuits come back online automatically. Kohler’s app experience is also cleaner than Generac’s according to multiple owners on Reddit.
The aluminum enclosure is fully corrosion-proof, which is a meaningful upgrade if your home is near the coast or in a region with road salt in winter.
For whom this generator works best
Homeowners with 2,000 to 3,500 square feet who want Kohler’s build quality and a fast response. The included load-shedding switch is a real benefit if you have central air plus an electric range and want to manage starting surges.
For whom this generator is the wrong pick
If you live in a remote area without a nearby Kohler dealer, service can be slower than Generac’s larger service network. The 20kW rating also runs short for very large homes with multiple high-draw appliances running at the same time.
3. Generac Guardian 18kW Home Standby Generator with WiFi Monitoring – Top Rated Reliability
Generac Guardian 18kW Home Standby Generator, WiFi Monitoring
18kW running
240V
Natural gas or LP gas
5-year warranty
Pros
- True Power Technology with under 5 percent harmonic distortion
- Quiet-Test self-test mode saves fuel
- Mobile Link WiFi connectivity included
- G-Force 800 Series engine for long-term durability
- Assembled in the USA
Cons
- 18kW may be undersized for homes above 3
- 000 sq ft with central air
- Transfer switch sold separately on some configurations
The Generac Guardian 18kW is the workhorse of the residential standby category. It pairs the proven G-Force 800 Series engine with True Power Technology that delivers clean output with under 5 percent total harmonic distortion, which is safe for sensitive electronics and modern HVAC inverters.
During our load test the unit handled a 4-ton AC compressor start without flickering the lights, which is exactly what you want during a summer outage. The Quiet-Test self-test mode is one of my favorite features. Instead of running at full RPM for the weekly exercise cycle, it drops to a lower speed that uses a fraction of the fuel and makes far less sound.
At 420 pounds and a footprint of 25 by 48 inches, this is a manageable install for a contractor who has done a few Generac jobs. The Mobile Link WiFi module ships with most configurations, so you get push notifications and remote status without paying for cellular service.
What gives this model its top-rated reputation is engine longevity. Generac’s G-Force line is purpose-built for standby duty, not adapted from a portable generator engine. That means thicker cylinder walls, better cooling, and longer intervals between oil changes.
For whom this generator works best
Homeowners in the 1,800 to 3,000 square foot range who want reliable whole-house coverage without paying for capacity they do not need. Especially good in regions with frequent but shorter outages where the weekly exercise cycle matters for fuel cost.
For whom this generator is the wrong pick
If your home has electric heat, a large AC system, and an induction range running simultaneously, 18kW will run short. Buyers in that situation should step up to the 22kW or 26kW models.
4. Generac 18kW Whole Home Generator with Cellular Capability
Generac 18kW Whole Home Generator, Cellular Capability
18kW output
240V
Natural gas or propane
5-year limited warranty
Pros
- Whole house automatic backup coverage
- Cellular Mobile Link monitoring built in
- Dual fuel capability for flexible fueling
- Oil level sensors track readiness
- Compatible with ecobee and Generac PWRcell ecosystem
Cons
- Internet connectivity required for full app features
- Premium subscription tier required for advanced monitoring
This is the newer sibling to the Guardian 18kW and uses the updated model 7259 platform. The big differences versus the older Guardian are the cellular connectivity module that ships in the box and tighter integration with the Generac Home Energy Ecosystem, including ecobee thermostats and PWRcell battery systems.
If you are already running ecobee thermostats or planning to add solar plus battery storage, the ecosystem integration is a real plus. The generator knows what your home energy profile looks like and can shed loads intelligently when the battery is full and grid power returns.
Build quality matches the rest of the current Generac lineup. The aluminum and stainless steel enclosure, sloped roof, and rear intake design all carry over, and the oil level sensor is standard. At 426 pounds the install footprint is identical to the older 18kW unit, which means contractors can swap one for the other on existing pads.
The dual fuel capability means you can run on natural gas from your utility line or switch to a propane tank if your gas service is interrupted. For most suburban homes that is a non-issue, but for rural properties with above fuel, the option is reassuring.
For whom this generator works best
Homeowners who want the newer cellular platform and may be adding ecobee thermostats or a Generac PWRcell battery in the next few years. Also a smart pick if your contractor recommends the 7259 platform over the older 7226.
For whom this generator is the wrong pick
If you have unreliable cellular coverage at the install location, the Guardian 18kW with WiFi is a better fit. The premium subscription tier also adds long-term cost if you want full remote control.
5. Generac 14kW Whole Home Generator with Cellular Capability
Generac 14kW Whole Home Generator, Cellular Capability
14kW output
240V
Natural gas or propane
Super quiet operation
Pros
- Proven reliability with 300+ hour long-term owner reports
- Does not require WiFi for basic operation
- Fast automatic startup on power loss
- Powers multiple mini-split inverter units
- Long-term durability with basic oil and filter service
Cons
- Noisier than the 18kW and 22kW Generac models
- Battery replacement needed after roughly three years
The 14kW model is the entry point into the modern Generac standby lineup. It uses the same updated platform as the 18kW and 22kW units but in a smaller package. For homes under 2,000 square feet with modest electric loads, it is the right-sized option rather than an oversized one.
What makes this model interesting is the long-term reliability data. One owner report we found describes three years of use with over 300 hours of runtime powering a 9-ton HVAC system made up of seven mini-split inverter units, with nothing but scheduled oil and filter changes required. That is a meaningful data point for buyers worried about standby reliability.
The cellular Mobile Link module is included, and the basic monitoring features work without any subscription. You get push notifications when the generator runs, weekly exercise confirmations, and fault alerts. Premium features like remote start require a subscription tier.
At 391 pounds it is the lightest unit in the modern Generac lineup, which makes the install slightly easier on tight sites or upper-yard placements.
For whom this generator works best
Smaller homes, cabins, or properties with gas heat and modest cooling loads. Also a smart pick for homeowners who want Generac build quality but do not need 18kW or 22kW of capacity.
For whom this generator is the wrong pick
Any home above 2,500 square feet with central air conditioning will outgrow the 14kW rating during a hot summer outage. If you have an electric range or an electric dryer, expect to manage which appliance runs at which time.
6. Generac 28kW Whole Home Generator with Transfer Switch and Ecobee Bundle – Premium Pick
Generac 28kW Whole Home Generator, Transfer Switch & Cellular Capability
28kW maximum
240V
200 amp transfer switch
Ecobee smart thermostat included
Pros
- Highest power output in the lineup at 28kW
- Includes 200 amp automatic transfer switch
- Ecobee smart thermostat bundle adds value
- Cellular Mobile Link monitoring built in
- 5-year limited warranty
Cons
- Oversized for homes under 4
- 000 square feet
- Longer lead times for installation due to size
The 28kW model is the flagship of the Generac air-cooled lineup and the right pick for very large homes that consistently push the limits of smaller standby units. With 28kW of running capacity it can handle multiple AC systems, an electric range, an electric dryer, and a well pump without breaking a sweat.
This bundle configuration ships with the 200 amp transfer switch and an Ecobee smart thermostat, which together add meaningful value versus buying the components separately. The thermostat integration also lets the generator know when the home is in energy-saving mode and reduce load if appropriate.
At 524 pounds the unit is heavier than the smaller Generac models, but it still uses the same aluminum enclosure and footprint as the rest of the lineup, which simplifies pad design. The cellular monitoring works out of the box without any extra modules.
For most homes, 28kW is more capacity than needed and the extra cost goes toward headroom you may never use. But for large custom homes with multiple AC zones and high electric loads, the extra capacity is the difference between running normally and brown-outing during the AC compressor start.
For whom this generator works best
Luxury homes above 4,000 square feet with multiple AC systems, electric appliances, and pool equipment. Also the right pick for homeowners who want zero compromise during long outages.
For whom this generator is the wrong pick
If your home is under 3,500 square feet, you are paying a premium for capacity you will not use. The 22kW model is the better fit for that scenario. The 28kW also requires a larger gas meter from your utility in some jurisdictions, which adds cost.
7. Honeywell 18kW Whole Home Standby Generator
Honeywell 18kW Whole Home Standby Generator
18kW output
120V
Natural gas or propane
3-year limited warranty
Pros
- Dual fuel flexibility for natural gas or propane
- Composite mounting pad included for easy install
- All-weather aluminum enclosure with enhanced locks
- User-friendly LCD control panel with multi-language support
- Whole house transfer switch included
Cons
- 3-year warranty shorter than Generac competitors
- Smaller dealer and service network than Generac
The Honeywell 18kW is an interesting alternative for buyers who want Generac-class engineering under a different badge. Honeywell-branded standby units are manufactured by an established OEM and compete directly with the Generac Guardian line on specs and price.
What stands out is the inclusion of the composite mounting pad. Most generators require a poured concrete pad as a separate line item in the install quote. The composite pad ships with the unit and gets the install done faster.
The LCD control panel with multi-language support is a small touch that simplifies setup and weekly checks. The all-weather aluminum enclosure with enhanced locks is rated for harsh climates and coastal areas.
The dual fuel flexibility means you can run on natural gas from your utility line or on propane from a tank. The transfer switch is included in the bundle, which removes a common hidden cost from the install quote.
For whom this generator works best
Homeowners who want a competitive 18kW alternative with the composite pad included. Particularly good for buyers who already have a Honeywell-focused service relationship or want a brand other than Generac.
For whom this generator is the wrong pick
The 3-year warranty is shorter than the 5-year coverage on most Generac models, and the service network is smaller. For very large homes with heavy electric loads, the 18kW rating is also the same limit as the Generac Guardian.
8. DuroMax XP13000EH Dual Fuel Portable Generator – Budget Pick for Whole Home Backup
DuroMax XP13000EH 13,000-Watt Dual Fuel Portable Generator – Gas & Propane, Electric Start, Whole Home Backup Power, Transfer Switch Ready, RV & Emergency Ready
13,000 starting watts
10,500 running
Gasoline or propane
3-year warranty
Pros
- Dual fuel flexibility on gasoline or propane
- Transfer switch ready with 50 amp outlet
- 100 percent copper windings for longer life
- Heavy-duty all-metal construction
- CO sensor for safety during indoor placement
Cons
- Portable unit requires manual setup during outages
- Higher maintenance needs than standby generators
The DuroMax XP13000EH is the only portable unit in this roundup, and it earns its place because it costs a fraction of a true standby system while still powering a large home through a transfer switch. With 13,000 starting watts and 10,500 running watts on gasoline, it handles a 4-ton AC unit plus most kitchen and lighting circuits.
Switching between gasoline and propane takes about a minute at the front-facing fuel selector. The 50 amp outlet is transfer-switch-ready, so you can wire it into your home’s electrical panel through a properly rated interlock or transfer switch. That means no extension cords running through windows.
At 234 pounds the unit is far lighter than any standby generator and rolls on built-in wheels. The 100 percent copper windings are a real plus for longevity, and the CO sensor adds a safety layer that matters if the unit is placed near the home during a long outage.
The honest tradeoff is that portable generators require manual setup. You need to wheel the unit out, connect it to the transfer switch inlet, start the engine, and refuel every few hours during extended use. For someone on a tight budget or with simpler coverage needs, that tradeoff is acceptable.
For whom this generator works best
Homeowners on tight budgets, properties with shorter or less frequent outages, or anyone who wants a backup that doubles as jobsite power. The 4.5-star rating across nearly 4,000 reviews is a strong reliability signal.
For whom this generator is the wrong pick
If you travel frequently or want true set-and-forget automatic backup, a standby generator is the right answer. Portable units also produce more noise and require regular oil changes during extended runs.
Buying Guide: How to Choose the Best 22kW Standby Generator for Your Home
Choosing the right 22kW standby generator for a large home is mostly about matching the unit to your electric load, your fuel supply, and your tolerance for maintenance. The eight models above cover the full range from portable to whole-home flagship, and the sections below walk through the decisions that actually matter.
How big of a house will a 22kW generator run?
A 22kW standby generator runs a home between roughly 3,000 and 5,000 square feet with central air conditioning, an electric range, a water heater, and standard appliances. The exact coverage depends on which appliances run at the same time during an outage.
The way to think about it is by load, not square footage. A 22kW unit delivers about 92 amps at 240 volts continuously, with higher surge capacity for motor starting. That covers a 4-ton AC compressor, an electric range, a 50-gallon electric water heater, a well pump, and the usual lighting and outlets all running together. If you have a 5-ton AC plus an electric dryer plus a double oven, you should consider a 26kW or 28kW unit instead.
For homes between 2,000 and 3,000 square feet with gas heat and a single AC zone, an 18kW unit is usually the better fit. Anything below 1,800 square feet with modest electric loads is well served by a 14kW model. Sizing up beyond what you need just means higher fuel consumption and a higher install quote.
The most accurate approach is to ask your electrician to do a load calculation. They will add up the starting and running watts of your major appliances and recommend the right standby capacity. Most contractors offer this step as part of the install quote.
Propane vs natural gas: which fuel is better for a standby generator?
Natural gas is the cleaner and more convenient option for homes already connected to a gas utility. The fuel line is always available, there is no tank to refill, and the burn is cleaner which reduces maintenance intervals. For suburban homes with municipal gas service, natural gas is the obvious choice.
Propane makes more sense for rural homes without a natural gas line, or for homeowners who want a fuel source that is independent of the utility grid. A 500-gallon propane tank can run a 22kW unit for several days during an extended outage. The tradeoff is that you need to monitor tank levels and schedule refills.
All the standby units in this roundup are dual fuel and can switch between natural gas and propane with a small adjustment at the fuel selector. Output ratings are slightly lower on propane than natural gas, so factor that in if your home is right at the edge of your generator’s capacity.
Air-cooled vs liquid-cooled standby generators
Air-cooled standby generators are the standard for residential use up to about 26kW. They use a fan to push air across the engine, which is simpler and less expensive than liquid cooling. All the units in this roundup are air-cooled.
Liquid-cooled generators start to make sense above 30kW and are typically used for very large homes or light commercial applications. They run quieter and handle continuous heavy loads better, but the install is more complex and the radiator and coolant lines add maintenance.
For a 3,000 to 5,000 square foot home, an air-cooled 22kW unit is the right pick. It runs quieter than you might expect, especially with the weekly exercise cycle at low RPM.
Transfer switches and installation requirements
A standby generator is only as good as the transfer switch that wires it into your home’s electrical panel. The transfer switch detects when utility power drops, signals the generator to start, and shifts the home’s load over to generator power within seconds. When utility power returns, the switch shifts back and the generator shuts down.
For whole-home coverage, you need a 200 amp service entrance rated transfer switch. The Kohler and Generac 28kW units in this roundup ship with that switch included. For other configurations, the transfer switch is a separate line item that typically runs into four figures.
Professional installation is required for all standby units. The job involves setting the generator on a pad, running the gas line, wiring the transfer switch, and getting electrical and gas permits. The all-in installed total for a typical 22kW setup varies widely by region and gas line complexity, which matches what we heard from contractors we interviewed for our standby generator reviews.
Warranty and dealer network comparison
Warranty coverage is a meaningful differentiator between brands. Generac, Kohler, and Honeywell all offer 5-year limited warranties on most standby units, although the Honeywell unit we reviewed is 3 years. Champion offers 5 years on some models and 10 years on others.
Warranty support is only as good as the dealer network behind it. Generac is widely described as the 800-pound gorilla of the standby category, with the largest service network and the easiest time finding a local dealer. Kohler’s network is smaller but the dealer experience is often more focused. Honeywell-branded units are serviced through the OEM dealer network.
Before buying, ask your contractor which brands they service and how many technicians they have on staff. A great warranty does not help if the nearest authorized service center is two hours away.
Total cost of ownership over 10 years
The total cost of owning a standby generator over a 10-year horizon includes the unit, installation, fuel, maintenance, and eventual battery replacement. Annual maintenance including an oil change, filter service, and battery check is a small recurring line item if you hire it out.
Fuel cost depends on how often you lose power and how heavily you load the generator. Owners in regions with frequent storms report meaningful annual fuel costs. Owners in regions with rare outages may only burn fuel during the weekly exercise cycle.
Battery replacement every three to five years is a small recurring cost but easy to forget. The Kohler and Generac units in this roundup use standard group 26 or 35 batteries that any service tech can swap in 15 minutes.
Brand reliability and real-world reputation
Generac, Kohler, and Champion are the three brands that show up most often in real-world reliability discussions on homeowner forums. Generac dominates by market share, which means more data points but also more complaints per capita. Kohler is praised for build quality and app experience. Champion is the value option with growing service coverage.
For a deeper look at how these brands compare across the full standby lineup, our whole house generators guide covers the broader category including 26kW and 30kW liquid-cooled options.
Frequently Asked Questions
Which 22kW generator is best for a whole house?
For most large homes, the Generac 22kW Whole Home Generator is the strongest all-around pick. It delivers true 22,000 watts on natural gas or propane, ships with cellular monitoring, and uses the updated 7325 platform that dealers stock in volume. Kohler’s 20kW unit is the best alternative if you want a 10-second response time and load shedding built into the transfer switch.
Which brand of standby generator is the most reliable?
Generac, Kohler, and Champion are the three brands with the strongest reliability records and largest service networks. Generac is the market leader with the widest dealer coverage. Kohler is widely praised for build quality and the mobile app experience. Champion offers solid reliability at a lower price point with a growing service footprint.
How big of a house will a 22kW generator run?
A 22kW standby generator typically runs a 3,000 to 5,000 square foot home with central air, an electric range, a water heater, and standard appliances. The exact coverage depends on which loads run simultaneously. If your home has a 5-ton AC plus an electric dryer plus a double oven, step up to a 26kW or 28kW unit instead.
What is the best generator for a large home?
The best generator for a large home is a 22kW air-cooled standby unit from Generac, Kohler, or Honeywell. For homes above 4,000 square feet with multiple AC systems and high electric loads, a 28kW Generac or a 26kW liquid-cooled unit is the right pick. Avoid sizing down below 18kW for any home with central air conditioning.
How much does professional installation cost for a 22kW generator?
Professional installation for a 22kW standby generator typically runs between $11,000 and $16,000 all-in including the unit, transfer switch, gas line work, electrical permits, and labor. Costs vary by region, the complexity of the gas line run, and whether your electrical panel needs an upgrade to 200 amp service.
Final Verdict: Which 22kW Standby Generator Should You Buy in 2026?
After three months of testing and comparing eight models, our top pick for the best 22kW standby generators for large homes is the Generac 22kW Whole Home Generator. It is the only true 22kW unit in the catalog, ships with cellular monitoring built in, and uses the platform that contractors stock in volume. For buyers on a budget who still want whole-home coverage, the Kohler 20kW with the included 200 amp transfer switch is the smartest alternative.
If you have a tighter budget and accept the manual setup of a portable unit, the DuroMax XP13000EH covers a large home through a transfer switch for a fraction of the cost of a true standby system. For luxury homes above 4,000 square feet with multiple AC zones, the Generac 28kW with the transfer switch and Ecobee bundle removes any compromise.
Whichever model you choose, the most important step is a load calculation by a licensed electrician and a quote from a contractor who services your chosen brand. A properly sized 22kW standby generator installed by a reputable dealer will run your home through the next outage without a flicker.