Short answer
For most U.S. households where outages are short (median ~8 hours/year per EIA), a 13.5 kWh battery is the better choice: silent, daily-useful for TOU arbitrage or solar self-consumption, integrates with solar. For hurricane country (FL, NC, LA, TX coast) and rural cold-climate locations where outages routinely last 3-7+ days, a natural-gas standby generator wins on unlimited runtime. Some homeowners install both.
Side-by-side comparison
| Dimension | 13.5 kWh Battery | 22 kW Standby Generator |
|---|---|---|
| Installed cost | $13,000–$19,000 | $11,000–$17,500 |
| Federal credit (2026) | 25D expired 2025-12-31 | never had federal credit |
| State programs | CA SGIP $2,000–$5,000, NY-Sun Storage, CT, MD | Few |
| Outage runtime | 12-24 hr essentials; 2-4 hr full AC | Unlimited on NG; 7-10 days on propane |
| Noise | Silent | 65-75 dB at 25 ft |
| Maintenance | Zero | $250–$450/yr service |
| Daily value | $200–$2,600/yr TOU or NEM 3.0 | $0 (self-tests burn fuel weekly) |
| Solar integration | Tight (Powerwall, Enphase, Franklin) | None |
| Lifespan | 12-15 yr | 10-15 yr (air-cooled) |
Scenarios — which wins for you
- "Boston suburb, occasional 4-hour storm outages, have solar." → Battery. Outages short, solar pairs perfectly, MA SMART works with battery. Generator overkill.
- "Florida hurricane country, expect 5-day outages." → Generator on natural gas. Battery can’t span 5 days; generator runs as long as gas flows.
- "Rural Vermont, ice storms knock out power 1-3 days, no gas service." → Generator on propane (500-gal tank) OR battery + generator combo if budget allows.
- "Phoenix, want backup for monsoon-season outages, time-of-use rate plan." → Battery. TOU arbitrage value alone pays a chunk of the install over 15 years.
- "California NEM 3.0, brand-new solar." → Battery (Powerwall 3 or Franklin). NEM 3.0 export rates are so low that battery self-consumption is essential to make solar economics work.
- "Suburban Texas, occasional grid stress, value resale appeal." → Generator. Buyer surveys consistently rank standby generators as a top desired feature in hurricane-adjacent regions.
Hybrid approach
Some homeowners in highest-risk regions (Florida hurricane belt, Louisiana, rural ice-storm country) install both systems behind a single transfer switch. The battery handles daily TOU + the first 12-24 hours of any outage (silent, solar-charged). The generator only auto-starts when battery state-of-charge drops below 20%. Combined installed cost: $25,000–$35,000. Best-of-both for households who can afford it.
Frequently asked questions
Which costs less installed?
In 2026, roughly the same. 13.5 kWh Powerwall-class battery: $13,000–$19,000 installed. 22 kW air-cooled standby generator + 200A ATS: $11,000–$17,500 installed. The federal 25D credit (30%) on batteries expired 2025-12-31, so neither has a federal credit advantage anymore. State programs (CA SGIP $2,000–$5,000, NY-Sun Storage, CT, MD) still apply to batteries in eligible states.
Which provides longer outage runtime?
Generator wins decisively for sustained outages. Natural-gas standby has unlimited runtime; propane runs 7-10 days on a 500-gal tank. A 13.5 kWh battery typically powers essentials for 12-24 hours or 2-4 hours of central AC. For 3-7+ day outages (hurricane country), generator is the only realistic answer.
Which has daily value beyond outages?
Battery wins. Daily TOU arbitrage in California, Massachusetts, New York, Hawaii saves $200–$1,200/yr. NEM 3.0 self-consumption with solar adds $1,800–$2,600/yr in CA. Generator provides $0 value between outages (and self-tests weekly burning fuel).
Noise and maintenance?
Battery: silent, zero maintenance, 12-15 yr lifespan. Generator: 65-75 dB at 25 ft (lawnmower volume), $250–$450/yr service, 10-15 yr typical residential lifespan. If you have close neighbors or value quiet, battery wins.
Can I have both?
Yes, and many hurricane-region homeowners do. Battery for daily/short-outage value + solar integration, generator for multi-day events. Roughly $25,000–$35,000 combined installed. Most utilities allow both behind one ATS; verify with your installer.