Backup power, compared by the numbers
Standby generators & backup power, compared honestly — specs, prices, and sizing math, no hype.
Quick answer
Most homes that want real outage protection land on a 14–24 kW standby generator ($9,500–$16,000 installed) or, for essentials-only backup, a 2–6 kWh portable power station ($500–$4,500). The right choice depends on three things: what you need to keep running, whether you have natural gas or propane, and how long your outages last. The guides below walk through the math with prices attached.
Not sure what size? Run your own numbers
Our generator size calculator adds up your actual loads — AC tonnage, pumps, water heater, EV charger, even your climate — and matches the result to a size class and the models in our dataset that fit it. Two minutes, no email required.
Most compared standby generators
| Model | Size | Approx. price | Warranty |
|---|---|---|---|
| Generac Guardian 26kW | 26 kW | $6,900 | 5 yrs |
| Generac Guardian 24kW | 24 kW | $6,600 | 5 yrs |
| Generac Guardian 22kW | 22 kW | $6,100 | 5 yrs |
| Generac Guardian 18kW | 18 kW | $5,100 | 5 yrs |
| Generac Guardian 14kW | 14 kW | $4,500 | 5 yrs |
| Kohler 26kW (26RCA) | 26 kW | $7,500 | 5 yrs |
| Kohler 20kW (20RCA) | 20 kW | $6,000 | 5 yrs |
| Kohler 14kW (14RCA) | 14 kW | $4,700 | 5 yrs |
| Cummins QuietConnect 20kW (RS20A) | 20 kW | $5,800 | 5 yrs |
| Cummins QuietConnect 13kW (RS13A) | 13 kW | $4,300 | 5 yrs |
| Champion 14kW Standby | 14 kW | $4,300 | 10 yrs |
Guides & comparisons
The best whole-home standby generators compared on specs, warranty, noise, and price — from 13kW essentials coverage to 26kW whole-house units.
The best portable generators from Honda, Westinghouse, Champion, DuroMax, WEN, and Firman compared on running watts, noise, fuel options, and price.
The best portable power stations from EcoFlow, BLUETTI, and Jackery compared on capacity, output, expandability, charging speed, and price.
The best solar panels for EcoFlow, Jackery, and BLUETTI power stations compared on watts, rigid vs. folding format, weight, compatibility, and price.
Cummins vs Champion standby generators compared size-for-size on dataset prices, output, and warranty.
Generac vs Champion standby generators compared size-for-size on dataset prices, output, and warranty.
Generac Guardian vs Cummins QuietConnect standby generators compared on price, noise, warranty, engines, and dealer networks.
Generac Guardian vs Kohler RCA standby generators compared on price, warranty, noise, engines, service networks, and monitoring apps.
The BLUETTI Apex 300 (2,765 Wh) runs a typical refrigerator for about 13 hours of compressor time - here is the math and the surge check.
The BLUETTI Elite 200 V2 (2,074 Wh) runs a typical refrigerator for about 10 hours of compressor time - here is the math and the surge check.
The EcoFlow DELTA 2 Max (2,048 Wh) runs a typical refrigerator for about 10 hours of compressor time - here is the math and the surge check.
The EcoFlow DELTA Pro 3 (4,096 Wh) runs a typical refrigerator for about 20 hours of compressor time - here is the math and the surge check.
The EcoFlow DELTA Pro Ultra (6,144 Wh) runs a typical refrigerator for about 30 hours of compressor time - here is the math and the surge check.
The Jackery Explorer 2000 Plus (2,042 Wh) runs a typical refrigerator for about 10 hours of compressor time - here is the math and the surge check.
The Jackery Explorer 300 Plus (288 Wh) runs a typical refrigerator for about 1.4 hours of compressor time - here is the math and the surge check.
Kohler vs Champion standby generators compared size-for-size on dataset prices, output, and warranty.
Kohler vs Cummins standby generators compared size-for-size on dataset prices, output, and warranty.
What standby generator maintenance actually involves — exercise cycles, oil and filter intervals, battery life, realistic DIY and dealer costs, and the failures that kill these units.
For a 1,000 sq ft house, the worked load math lands on a 13 kW standby generator (14 kW for extra margin) for whole-home coverage.
For a 1,500 sq ft house, a 14 kW standby generator covers most homes whole-house; gas-appliance homes need less, all-electric homes may need 18–20 kW.
For a 2,000 sq ft house, most homes need a 14–18 kW standby generator for essential circuits, or 20–24 kW for whole-home coverage with load management.
For a 2,500 sq ft house, the worked load math lands on a 18 kW standby generator (20 kW for extra margin) for whole-home coverage.
A 3-ton AC draws about 3,120 running and 6,240 starting watts; with home essentials the math lands on a 13 kW standby generator.
A 3,000 sq ft house usually needs a 22–26 kW standby generator for whole-home coverage, or 20 kW with disciplined load management.
For a 3,500 sq ft house, the worked load math lands on a 20 kW standby generator (22 kW for extra margin) for whole-home coverage.
A 4-ton AC draws about 4,160 running and 8,320 starting watts; with home essentials the math lands on a 14 kW standby generator.
For a 4,000 sq ft house, the worked load math lands on a 26 kW standby generator for whole-home coverage.
A 5-ton AC draws about 5,200 running and 10,400 starting watts; with home essentials the math lands on a 18 kW standby generator.
A 5,000 sq ft house peaks beyond the 26 kW air-cooled standby class; here is the load math and what 26 kW honestly covers.
Running a hot tub (240V spa) needs 7,000 running / 7,500 starting watts - the portables and standby class that honestly cover it.
Running a sump pump (1/3 hp) needs 800 running / 1,600 starting watts - the portables and standby class that honestly cover it.
Running a well pump (1 hp) needs 2,000 running / 4,000 starting watts - the portables and standby class that honestly cover it.
Running an electric range needs 5,000 running / 5,000 starting watts - the portables and standby class that honestly cover it.
Running an EV charger (Level 2, 40A) needs 9,600 running / 9,600 starting watts - the portables and standby class that honestly cover it.
Whole house generator costs in 2026 broken down by size — equipment, transfer switch, gas line, permits, and labor — plus running costs and ways to save.