Generators win on run time: as long as you have fuel, they can power a home through a week-long outage, including heating loads a battery can't sustain. Batteries win on everything else that matters day to day: they're silent, emission-free, switch over instantly, need little maintenance and can save money on time-of-use rates. Which one suits you depends on how long your outages last, what you need to run and how you heat your home.
Key takeaways
- Batteries offer clean, quiet, automatic backup but store a limited amount of energy.
- Generators can run for days on fuel but produce noise, exhaust and carbon monoxide, and need regular maintenance.
- Approximate installed costs: portable generator $800–$3,000 (plus transfer switch), standby generator $10,000–$20,000, home battery $12,000–$20,000.
- For rural homes facing long winter outages, a battery paired with a small generator can combine the strengths of both.
- Never run a generator indoors or in a garage, and never backfeed your home without a proper transfer switch.
Head-to-head comparison
| Factor | Home battery | Portable generator | Standby generator |
|---|---|---|---|
| Approx. installed cost | $12,000–$20,000 | $800–$3,000 + $500–$1,500 transfer switch | $10,000–$20,000 |
| Run time | Hours to ~2 days per battery (longer with solar) | As long as you refuel | Days to weeks on natural gas or large propane tank |
| Switchover | Automatic, near-instant | Manual: start, plug in, switch over | Automatic, typically 10–30 seconds |
| Noise | Near silent | Loud | Moderate to loud |
| On-site emissions | None | Exhaust, CO | Exhaust, CO |
| Maintenance | Minimal | Oil changes, fuel stabilizer, test runs | Annual service, weekly self-tests |
| Everyday value | Time-of-use savings, solar storage, possible grid programs | None | None |
| Heavy loads (electric heat, central A/C) | Usually not | Limited by size | Yes, if sized for it |
All costs are approximate Canadian ranges and vary with size, brand and installation complexity.
Where generators come out ahead
Long outages
When a major ice storm or windstorm leaves a rural area without power for several days, a generator with enough fuel keeps going. A battery, especially in winter when solar recharge is minimal, will eventually run down. Our article on solar plus battery backup explains the winter solar challenge.
Big loads
A properly sized standby generator can run central air, a well pump, an electric water heater and even electric heating. Doing the same with batteries requires several units and a much larger budget.
Upfront cost for basic coverage
A portable generator with a transfer switch is the cheapest way to keep a fridge, furnace and sump pump running. For a household on a tight budget, that matters.
Where batteries come out ahead
Safety and air quality
Carbon monoxide from generators is a serious hazard and a leading cause of injuries during power outages. Generators must run outdoors, well away from windows, doors and vents. Batteries produce no exhaust at all.
Convenience
A battery takes over automatically, often before you notice the lights flickered. There's no refuelling in a storm, no stale gasoline, no pull-cord on a -25°C night.
Year-round value
A generator sits idle until there's an outage. A battery can shift electricity use to cheaper hours, store solar power and, in some regions, earn payments through grid programs. Whether those savings add up is explored in Is a home battery worth it?.
Emissions and noise
Generators burn gasoline, diesel, propane or natural gas, emitting greenhouse gases and local air pollutants. Neighbours notice the noise, too, and some municipalities have bylaws on generator placement and noise. For context on emissions from home energy choices, see our carbon page.
Fuel considerations for generators
- Gasoline: widely available but goes stale within months without stabilizer, and storing large amounts is a fire hazard. Gas stations may not pump during a regional outage.
- Propane: stores indefinitely; a large tank can run a standby generator for days.
- Natural gas: effectively unlimited supply for standby units, assuming gas service continues during the outage.
- Diesel: efficient, but less common for homes.
The hybrid approach
Many rural Canadian households end up with both:
- A battery (often with solar) handles short outages, which are the most common, silently and automatically.
- A small generator recharges the battery during rare, extended winter outages, running only a few hours a day rather than continuously.
Some battery systems support a generator input directly, which simplifies this. Ask your installer before you buy if a hybrid setup interests you.
Questions to help you decide
- How long are your typical outages? Mostly under a day? A battery handles that well. Several days, several times a year? Consider a generator or hybrid.
- How do you heat? Gas furnace or boiler: a battery can run the blower or pumps. Electric heat or a heat pump: you'll need a lot of capacity, which favours a generator or a multi-battery system.
- Do you have a well or sump pump? Check surge requirements for either option.
- Is time-of-use pricing available where you live? If so, a battery has extra value.
- What's your tolerance for maintenance and noise?
Local incentives occasionally apply to batteries, particularly with solar, but they change. Check our rebate finder by address.
Frequently asked questions
Can I connect a portable generator by plugging it into an outlet?
No. Backfeeding through an outlet is dangerous and illegal in Canada; it can energize utility lines and electrocute workers. Use a properly installed transfer switch or interlock, installed under permit by a licensed electrician.
How long will a standby generator run on propane?
It depends on tank size and load. A large residential tank can typically run a standby generator for several days under moderate load; your installer can estimate run time for your setup.
Do batteries work in extreme cold?
Yes, if installed in a suitable location or equipped with internal heating. Lithium batteries shouldn't charge below about 0°C without heating, so check the rated operating range for garage or outdoor installs.
The bottom line
There's no universal winner. Generators remain the practical choice for long outages and heavy electric loads, while batteries deliver safer, quieter, cleaner backup that also earns its keep year-round. For many Canadian homes, especially rural ones, the best answer is a battery for everyday resilience with a small generator held in reserve.
Sundamentals is an independent, non-profit education platform. Program details and prices change often — check current programs for your address in our rebate finder.