Battery backup calculator (Canada)
Winter storms and ice make outage planning different in Canada: the furnace blower and the sump pump matter more than air conditioning. Tick what you need, set how long the outage lasts, and see how many batteries cover it.
What do you need during an outage?
Example wattages: check the label on your own appliance and edit. Hours are per day of outage.
Outage and battery
Many owners keep some charge back for the next outage. 0% uses the full battery.
Your backup estimate
- Energy needed per day
- 3.2 kWh
- Energy needed for the outage
- 3.2 kWh
- Energy the batteries must supply
- 3.2 kWh
- Peak load if everything runs at once
- 1.4 kW
- Batteries needed for energy
- 1 unit
- Batteries needed for power
- 1 unit
- Recommended: Tesla Powerwall 3
- 1 unit
- Runtime on battery alone
- 102 hours
- Estimated installed cost
- $17,996
Estimates only. With solar, at least half a day of use is assumed to be stored for the night. Cost uses EnergySage first-half 2026 average quotes per kWh for each brand (converted to local currency where the sources say so).
Motor loads (pumps, AC, fridge compressors) draw several times their running watts for a moment when they start. Check the battery's start rating (LRA) against your largest motor.
Defaults and sources
- Appliance energy method
- Daily kWh = watts × hours used ÷ 1,000; use the wattage on your appliance label. A refrigerator runs at full wattage about a third of the time it is plugged in.U.S. DOE Energy Saver, Estimating Appliance and Home Electronic Energy Use · checked Oct 27, 2026
- Tesla Powerwall 3
- 13.5 kWh AC, 11.5 kW continuous, starts loads up to 185 LRATesla Powerwall 3 datasheet (North America) · checked Oct 27, 2026
- FranklinWH aPower 2
- 15 kWh AC, 10 kW continuous (15 kW peak for 10 s), 185 A LRAFranklinWH aPower 2 datasheet (V2.0) · checked Oct 27, 2026
- Enphase IQ Battery 5P
- 5.0 kWh usable, 3.84 kVA continuous (7.68 kVA for 3 s)Enphase IQ Battery 5P datasheet (DSH-00010-2.0, July 2023) · checked Oct 27, 2026
- Installed home battery price
- No Canadian survey exists; US EnergySage first-half 2026 averages converted at the Bank of Canada first-half 2026 average of 1.3781 CAD per USD (about $1,330-$1,970/kWh)EnergySage (US quotes) and Bank of Canada FXUSDCAD · checked Oct 27, 2026
- Solar production per kW
- Modelled for the largest city in your provincePVGIS 5.3 (European Commission JRC): south-facing, 30 degree tilt, 14% system losses, ERA5 weather 2005-2023 · checked Oct 27, 2026
- Canada Greener Homes Loan
- Closed: funding fully committed, no new applicationsNatural Resources Canada · checked Oct 27, 2026
How the calculator works
Each appliance's daily energy is its watts times the hours it runs, divided by 1,000. The calculator adds what you tick, multiplies by the outage length and subtracts what your solar can put back each day at the share you set; winter output in most provinces is low, so a cautious share is wise.
It sizes batteries for both stored energy (after your reserve) and peak power, and recommends whichever needs more units. Battery prices are US EnergySage averages converted to Canadian dollars, because no Canadian price survey exists.
Battery backup in Canada: common questions
Can a home battery run my furnace in a power outage?
A gas furnace's blower is a modest load, around 500 W in this calculator's example, so one 13.5 kWh battery can run it for a day alongside a fridge, lights and internet. Electric baseboard or electric furnace heating draws several kilowatts and empties a battery within hours.
How much does a home battery cost in Canada?
There is no Canadian price survey. Converting EnergySage's first-half 2026 US averages at the Bank of Canada rate gives about $1,330-$1,970 per kWh installed, or roughly $18,000 for a 13.5 kWh Tesla Powerwall 3. Get local quotes.
Are there rebates for home batteries in Canada in 2026?
There is no federal homeowner programme open: the Canada Greener Homes Loan has closed. Some provinces and utilities run their own storage or demand-response programmes; check yours before buying.