Quick answer: If outages are occasional and you're on a budget, a portable generator is the right choice. If outages are frequent, you have a medical dependency, or you want automatic protection you don't have to think about, a standby generator justifies the higher cost.
Side-by-Side Comparison
| Factor | Portable | Standby |
|---|---|---|
| Unit cost | $400–$2,500 | $3,000–$15,000+ |
| Installation cost | $500–$1,500 (transfer switch) | $1,500–$5,000 |
| Total installed cost | $900–$4,000 | $4,500–$20,000+ |
| Startup | Manual | Automatic (seconds) |
| Fuel type | Gasoline / dual-fuel | Natural gas / propane |
| Fuel storage | Required (finite) | Utility line (unlimited) |
| Typical output | 2,000–12,000W | 7,500–22,000W+ |
| Noise level | 65–80 dB | 60–70 dB |
| Portability | Yes — can move and store | Permanently installed |
| Permits required | Usually no | Yes — electrical + gas |
| Good for renters | ✓ Yes | ✗ No |
Portable Generators: The Details
A portable generator is exactly what it sounds like — a wheeled, gasoline-powered unit you pull out of the garage when needed, wheel to a safe location outdoors, and start manually. They've been the dominant choice for American homeowners for decades because of their low upfront cost and flexibility.
What they're good at
- Budget backup power: A $800 dual-fuel portable with a $600 transfer switch installation gives you reliable essential-load coverage for under $1,500 total.
- Portability: You can use the same generator at a job site, on a camping trip, or at a second property.
- No HOA or permit issues: Portable generators typically don't require building permits or HOA approval since they're not permanently installed.
- Renter-friendly: You own the generator and take it with you when you move.
Limitations to understand
- Manual startup: You must physically go outside, wheel it to position, add fuel if needed, and pull the cord (or press the electric start) every time. During a 2 AM winter outage, this is a real friction point.
- Finite fuel supply: You're limited to whatever gasoline you have stored. In extended outages after major storms, gas stations run dry quickly. Planning ahead with 20–30 gallons stored is essential.
- Noise and exhaust: Portable generators are louder than standby units and must be kept 20 feet from the home. In dense neighborhoods, this can be an issue.
- Limited runtime per tank: Most portable generators run 8–12 hours per tank at 50% load, requiring refueling during extended outages. See our Runtime Estimator for your specific model.
Standby Generators: The Details
A standby generator is a permanent outdoor appliance, like a central air conditioner, that sits next to your home on a concrete pad. It's connected to your home's electrical panel via an automatic transfer switch (ATS) and to your natural gas or propane supply. When utility power fails, the generator starts automatically within 10–30 seconds.
What they're good at
- Fully automatic operation: You don't have to do anything. Power goes out, generator starts. Power comes back, generator shuts off and reconnects to utility. You might sleep through the entire event.
- Unlimited runtime on natural gas: Connected to a utility gas line, a standby generator can run indefinitely (subject to maintenance intervals). No fuel storage required.
- Whole-home coverage: 20kW+ standby generators can power your entire home including central AC, electric range, and EV charger.
- Quiet and discreet: Installed away from the home with proper exhaust routing, standby generators are significantly quieter in practice than portables.
- Critical for medical needs: For homes with oxygen concentrators, nebulizers, or refrigerated medications, automatic standby power isn't a luxury — it's a safety requirement.
Limitations to understand
- High upfront cost: A properly installed 14kW standby generator typically costs $6,000–$12,000 all-in. Whole-home units run $15,000–$20,000+.
- Permit and inspection requirements: Installation requires electrical and gas permits in most jurisdictions, plus inspections. Plan for 2–4 weeks lead time.
- Propane dependency risk: If your standby runs on propane and your tank empties during an extended outage, you're without power just like with a portable.
- HOA restrictions: Some homeowner associations regulate standby generator placement, appearance, or noise levels. Check before buying.
- Annual maintenance: Standby generators require annual oil changes, filter replacements, and coolant checks. Most manufacturers sell annual service plans for $150–$300/year.
How to Decide
Ask yourself these four questions:
- How often do you lose power? If your area experiences 1–2 outages per year lasting a few hours each, a portable is almost certainly sufficient. If you lose power 4+ times per year or experience multi-day outages, the automation and convenience of standby begins to justify the price.
- Do you have medical equipment or other critical systems? If yes, standby is the appropriate choice.
- What's your budget? Be honest. A $12,000 standby install finance decision is different from a $1,200 portable cash purchase. Don't overextend.
- Are you renting or plan to move? Portable generators are personal property. Standby generators are improvements to real property — they may increase your home's value, but you can't take them with you.
The most common mistake: Buying a standby generator far larger than needed. A 7,500W essential-load standby covers most households' critical needs — refrigerator, furnace, a few circuits — for roughly half the cost of a 14kW whole-home unit. Use our Generator Size Calculator to determine your actual essential load before getting quotes.
Not sure what size you need? Our free calculator reveals your exact required wattage — essential for comparing quotes and avoiding over-buying.
Calculate Your Load →