Two different kinds of backup
A generator makes electricity by burning fuel. A home battery stores electricity, from the grid or from solar panels, and releases it when the grid fails. Both can keep a furnace and fridge running in an outage, but they behave very differently over hours and days.
For a typical Edmonton home, the right answer depends on how long you want to ride out, what you need running, and whether you have, or plan to add, solar.
It is also worth separating two goals. Some people want backup only for outages. Others want to use stored energy every day, for example to store solar production or shift usage. A battery can do both. A generator only does the first.
How battery backup is wired
A battery system has an inverter that converts stored DC power to the 120/240 V AC your house uses. For backup, it must also be able to isolate your home from the grid during an outage, for the same lineworker-safety reasons as a generator transfer switch.
Most installations move a short list of circuits to a separate critical loads panel that the battery supplies. Some larger systems back up the whole home with load management.
If the battery is paired with solar and connects to the grid, the system falls under Alberta's Micro-generation Regulation, which involves notifying and coordinating with your wire services provider before connecting. Our battery storage and residential solar teams handle that paperwork.
Runtime is the big difference
A battery holds a fixed amount of energy. How long it lasts depends on how much you draw. A gas furnace blower, fridge and a few lights can run a long time on a well-sized battery. Add electric heat, a kettle and a dryer and it drains fast.
A generator on natural gas keeps going for days. That matters in the rare multi-day outages that follow major storms.
The way you use a battery during an outage matters too. Many systems let you see the state of charge on an app, so you can turn off non-essential loads and stretch runtime. Setting your critical loads panel up carefully at installation makes this much easier, because the circuits that matter are already separated from the ones that do not.
Think about the furnace in particular. In a January outage it may run for long stretches, and its blower is the load that keeps your home and pipes from freezing.
Winter considerations
- Battery temperature. Many lithium batteries cannot charge below freezing and lose capacity in the cold. Location matters: inside a heated space or in an enclosure with heating, following the manufacturer's instructions and code requirements for where batteries may be installed.
- Solar in December. Short days and snow-covered panels mean little recharging in mid-winter. Do not count on solar to refill a battery during a January outage.
- Generators in the cold. Need a cold-weather kit and pre-winter service but are otherwise built for outdoor use.
- Heating load. Your furnace is the priority load. Make sure whatever you choose covers its blower and controls.
Where batteries may go in a home, and what separation or protection they need, depends on the system and the codes in force. Your installer confirms this with the permit authority.
Comparing the options
| Battery backup | Standby generator | |
|---|---|---|
| Switch-over | Near instant, often unnoticed | Within seconds |
| Runtime | Limited by stored energy | As long as fuel is supplied |
| Noise and exhaust | Silent, none | Engine noise, exhaust outdoors |
| Day-to-day use | Can store solar or shift usage | Only used in outages and exercise |
| Maintenance | Little routine service | Annual service, oil, battery |
| Winter recharge | Grid or generator; solar is weak | Not applicable |
Cost drivers differ too. Battery cost tracks storage capacity and inverter size. Generator cost tracks size, distance to the panel and gas meter, and any gas supply upgrades.
When a combination makes sense
Some homes pair a battery with a small generator. The battery handles short outages silently and covers the switch-over. If an outage drags on, the generator recharges the battery a few hours a day. This needs equipment designed to work together, so plan it as one system.
If you want the simplest long-duration backup, see standby vs portable generators. If you want quiet backup plus everyday value from solar, a battery is worth a look.
Think about the last few outages you had. If they were mostly a few hours, a battery covers you well. If you worry about multi-day events in deep cold, lean toward a generator or a combination.
Whichever way you go, the transfer and isolation equipment must be installed by a licensed electrician under permit, and the critical circuits chosen with your winter needs in mind. Bring a list of what you want running and a rough idea of how long, and the options narrow quickly.
Common questions
Will a battery run my furnace?
A gas furnace's blower and controls are a modest load that a suitably sized battery can carry for a useful time. Electric furnaces and baseboard heat are much larger loads and drain a battery quickly.
Does a battery need solar panels?
No. A battery can charge from the grid and hold that energy for outages. Solar adds the ability to recharge during the day and to use stored energy every day.
Can the battery go in my garage?
It depends on the product, its temperature limits and the code requirements for that location. An unheated Edmonton garage gets far too cold for many batteries to charge.
Do I need a permit?
Yes. Battery and inverter installations are electrical work requiring a permit, and grid-connected systems with solar also go through the Micro-generation process.
Codes and permit rules change and every building is different. For work on your system, talk to a licensed electrician and your local permit authority.