A vehicle block heater on a 2 to 4 hour timer uses roughly 0.8 to 4 kWh a night, which is about 10¢ to 48¢ in energy charge at the regulated 12.01¢/kWh rate. Left plugged in all night for 12 hours, the same heaters use 4.8 to 12 kWh, so a timer is the easiest way to cut the cost.
Electricity is billed by the kilowatt-hour (kWh). To work out what a heater costs: watts × hours ÷ 1,000 = kWh, then kWh × rate. For example, a 600 W block heater on for 4 hours is 600 × 4 ÷ 1,000 = 2.4 kWh, and at 12.01¢/kWh that is 2.4 × $0.1201 = $0.29.
Vehicle block heaters: manufacturer listings for common frost-plug and cartridge block heaters run from 400 W and 600 W (Kat's Heaters) to 1,000 W (Zerostart) and above for larger engines. Your owner's manual or the label on the heater gives the real figure.
Garage heaters: plug-in models are limited to about 1,500 W on a regular household outlet, while hard-wired or 240 V ceiling and wall units are commonly rated several kilowatts. One manufacturer's compact garage heater line (King Electric GH series) is rated 5, 7.5 and 10 kW at 240 V.
Winter in Whitecourt, Grande Prairie and the rest of northern Alberta means a lot of plug-in nights. Here is what each plug-in costs in energy charge at the regulated Rate of Last Resort and at Bright Fire's 1-year fixed rate, using a 30-night month.
| Heater and plug-in time | Energy per night | RoLR 12.01¢ per night | Bright Fire 8.29¢ per night | RoLR per 30 nights | Bright Fire per 30 nights |
|---|---|---|---|---|---|
| 400 W, 2 hours (timer) | 0.8 kWh | $0.10 | $0.07 | $2.88 | $1.99 |
| 400 W, 4 hours (timer) | 1.6 kWh | $0.19 | $0.13 | $5.76 | $3.98 |
| 400 W, 12 hours (all night) | 4.8 kWh | $0.58 | $0.40 | $17.29 | $11.94 |
| 600 W, 2 hours (timer) | 1.2 kWh | $0.14 | $0.10 | $4.32 | $2.98 |
| 600 W, 4 hours (timer) | 2.4 kWh | $0.29 | $0.20 | $8.65 | $5.97 |
| 600 W, 12 hours (all night) | 7.2 kWh | $0.86 | $0.60 | $25.94 | $17.91 |
| 1,000 W, 2 hours (timer) | 2 kWh | $0.24 | $0.17 | $7.21 | $4.97 |
| 1,000 W, 4 hours (timer) | 4 kWh | $0.48 | $0.33 | $14.41 | $9.95 |
| 1,000 W, 12 hours (all night) | 12 kWh | $1.44 | $0.99 | $43.24 | $29.84 |
Energy charge only. These tables multiply kWh by the energy rate. They do not include delivery charges (which also have per-kWh parts), local access fees, GST or the $9.99 per month Bright Fire admin fee, so your bill will be higher than the figures shown. Rates as of October 2026: Rate of Last Resort 12.01¢/kWh (EPCOR and FortisAlberta areas; 12.02¢ in ATCO Electric areas, 12.06¢ in Calgary and Red Deer), set through December 31, 2026; Bright Fire 1-year fixed 8.29¢/kWh. This is a comparison of published rates, not a guarantee of savings.
A garage heater is a different scale: it is rated in kilowatts, not hundreds of watts. These figures assume the heater runs continuously, which is the upper limit; a thermostat will cycle it off once the space is warm.
| Garage heater | RoLR per hour | Bright Fire per hour | RoLR per 4 hours | Bright Fire per 4 hours | RoLR, 20 four-hour sessions | Bright Fire, 20 four-hour sessions |
|---|---|---|---|---|---|---|
| 1,500 W plug-in (120 V) | $0.18 | $0.12 | $0.72 | $0.50 | $14.41 | $9.95 |
| 5,000 W (5 kW, 240 V) ceiling or wall unit | $0.60 | $0.41 | $2.40 | $1.66 | $48.04 | $33.16 |
Energy charge only. These tables multiply kWh by the energy rate. They do not include delivery charges (which also have per-kWh parts), local access fees, GST or the $9.99 per month Bright Fire admin fee, so your bill will be higher than the figures shown. Rates as of October 2026: Rate of Last Resort 12.01¢/kWh (EPCOR and FortisAlberta areas; 12.02¢ in ATCO Electric areas, 12.06¢ in Calgary and Red Deer), set through December 31, 2026; Bright Fire 1-year fixed 8.29¢/kWh. This is a comparison of published rates, not a guarantee of savings.
Sources: Natural Resources Canada, Block Heaters Save Fuel and Help the Environment (Office of Energy Efficiency); manufacturer listings for Kat's Heaters and Zerostart block heaters; King Electric GH series garage heater datasheet.
For a 400 W heater plugged in for 12 hours it is 4.8 kWh, about $0.58 at the regulated 12.01¢/kWh rate or $0.40 at 8.29¢/kWh, energy charge only. A 1,000 W heater for 12 hours is 12 kWh, about $1.44 or $0.99. The same heaters on a 2 hour timer cost $0.10 and $0.24 at 12.01¢. Delivery charges, GST and fees are extra.
Natural Resources Canada suggests an automatic timer that switches the block heater on two hours before you plan to drive, instead of leaving it plugged in all night. Your owner's manual may give a different figure for your vehicle.
Check the label or your owner's manual. Manufacturer listings for common engine block heaters run from about 400 W for small frost-plug models through 600 W to 1,000 W and above for larger engines. The cost is the same formula for any of them: watts × hours ÷ 1,000 × rate.
Look for the wattage on the nameplate. A 5,000 W (5 kW) 240 V heater that runs continuously for one hour uses 5 kWh, about $0.60 at 12.01¢/kWh or $0.41 at 8.29¢/kWh, energy charge only. A thermostat cycles the element on and off, so the real running time is usually less than the clock time.
Delivery charges are set by your wires company and are the same with every retailer, but they also have per-kWh parts, so they add to the cost of every kWh you use. The tables show the energy charge, the part that depends on your retailer, so you can see the effect of the rate itself. GST is extra on the whole bill.
Natural Resources Canada says that at -20°C a block heater can improve overall fuel economy by as much as 10 percent, and for a single short trip at -25°C the fuel savings could be in the order of 25 percent. It also helps the engine start more easily and reach operating temperature faster.
Your winter plug-in costs scale with your rate. Run the free Bill Check or compare plans on the rate card.
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