Electricity · small loads that add up
Phantom power and smart plugs: how much can you actually save?
Use your electricity bill and measured standby loads to decide where a smart plug or panel monitor can pay off—and which devices should never be cut automatically.
The short answer
Natural Resources Canada says standby power can represent 5–10% of a household electricity bill, but that does not mean a smart plug can recover all of it. Some loads must remain on, newer devices already use little power and the smart plug consumes a small amount itself. Measure first, then automate only the avoidable loads with enough off-hours.
Entertainment centres, office peripherals or legacy devices with a measurable idle load and predictable unused hours.
Routers, leak protection, sump alarms, medical devices, refrigerators or anything whose safety, updates or remote access depend on continuous power.
Quebec electricity is relatively inexpensive, so dollar payback can be slower even when kWh savings are real. A monitor is often more valuable for finding one abnormal load than for cutting every standby watt.
Before shopping
Five checks that eliminate the wrong choices
Complete these checks in order. One physical or electrical incompatibility matters more than ten app features.
- 01
Measure watts in active, idle and fully off states.
- 02
Estimate true unused hours per day.
- 03
Identify devices that must remain connected for safety or network access.
- 04
Compare annual dollars saved with the complete device cost.
- 05
Recheck after firmware, device or household routine changes.
Useful comparison
Monitoring and switching solve different problems
A panel monitor finds large or hidden consumption patterns. A metering smart plug measures and switches one outlet. Choose from the question you need answered.
| Approach | Best use | Main limit |
|---|---|---|
| Electricity-bill estimate | Sets an upper planning range | Cannot identify the responsible device |
| Metering smart plug | One plug-in load and scheduled cutoff | Load rating and device behaviour must be compatible |
| Panel energy monitor | Whole-home and circuit-level patterns | Installation and circuit identification are more involved |
Personal calculation
Phantom-load calculator
Estimate the avoidable share, then verify it with a real measurement before buying multiple plugs.
The result assumes the selected share can actually be switched off. Confirm it by measurement and subtract the plug’s own consumption.
Action plan
Find the loads worth automating
Measure for a week
Capture weekdays, weekends and overnight behaviour before creating a schedule.
Convert watts to annual cost
Watts × idle hours per day × 365 ÷ 1,000 gives annual kWh; multiply by the applicable marginal rate.
Automate with a fallback
Keep a manual button and verify that power restoration does not leave the device in an unsafe or unusable state.
Your situation changes the answer
Three concrete scenarios
5 W avoidable for 20 hours per day
36.5 kWh per yearAt a low electricity rate, dollar savings may not repay an expensive plug quickly.
25 W office setup idle 16 hours per day
146 kWh per yearThis is large enough to calculate seriously, provided the equipment tolerates hard cutoff.
Unknown whole-home increase
Use a panel monitor firstSwitching random outlets may miss an abnormal heating, pump or appliance circuit.
Exact products to compare
A clear role for each product, without a forced winner
Amazon.ca links lead to the exact verified model. Stock and seller can change; compatibility remains the first filter.
Kasa KP125MP2 Matter plugs with energy monitoring
Outlet-level energy monitoring plus scheduling can verify and remove a measured idle load.
- Pack
- Two plugs
- Maximum load
- 15 A / 1,800 W
- Measurement
- Outlet-level energy monitoring
Emporia Vue 3 with 16 circuit sensors
Panel and circuit visibility helps locate the large loads before buying switches.
- Included sensors
- 16 branch-circuit sensors plus mains
- Location
- Inside the electrical panel
- Use
- Real-time circuit and whole-home monitoring
RoboStead may earn a commission from qualifying purchases made through Amazon.ca links, without affecting recommendation order.
FAQ
Common questions before buying
Can phantom power really be 10%?
NRCan gives a household range of 5–10%, but your home may be lower or higher. It includes many devices and does not mean all standby use is avoidable.
Should I put the router on a smart plug?
Usually no if it provides the connection used to control that plug, security devices or alerts. Network restart schedules can also create reliability problems.
How do I calculate annual kWh?
Multiply measured standby watts by avoidable hours per day and 365, then divide by 1,000. Use the marginal electricity rate that applies to those kWh.
Is a panel monitor an energy saver?
No. It measures. Savings occur only when the information leads to a repaired fault, changed schedule, lower setting or replaced device.
Official sources checked August 30, 2026: Natural Resources Canada standby power · Hydro-Québec phantom loads · Hydro-Québec smart power bars · Hydro-Québec usage calculators · RoboStead methodology · Report a correction