Standby load is the power a device drinks while it is switched “off”, and it never appears as a line on the bill. A smart plug fixes it only if you know which socket deserves one. Most households buy six plugs first and measure a device second, which is the wrong order and the reason the exercise feels pointless.
Measure the socket before buying anything
Borrow or buy a single plug with metering and move it around for a week. The readings are consistent and often surprising. A cable or satellite set-top box pulls 15–30 W in standby because it keeps the tuner and the programme guide live. A console in “Instant On” sits at 10–15 W — the Xbox Series X is the usual offender, while a PS5 in rest mode is closer to 2 W. A laser printer holds 3–6 W to keep the fuser warm, and a microwave clock eats 2–3 W. The television is almost never the problem: sets sold since 2013 are capped near 0.5 W in standby by EU ecodesign rules and by ENERGY STAR criteria.
Add the plug’s own appetite, 0.7–1.5 W for a Wi-Fi model, and anything drawing under about 5 W does not justify a socket.
Buy the version with a meter
The TP-Link Tapo P110 is the sensible reference point: 16 A and 3680 W rating, 2.4 GHz Wi-Fi only, and a running kWh counter in the app. It sells for about $15 (BDT 1,700–2,000). The P100 is the same relay without metering for around $10 and is a false economy for this job, because you cannot prove the saving. Shelly’s Plus Plug S costs nearer $25 and exposes a local HTTP API, which matters if you would rather not depend on a vendor’s cloud staying online.
Two specification traps catch people. The radio is 2.4 GHz only, so it will not join a 5 GHz-only SSID — on a mesh system that is why a plug “refuses to connect”, and splitting the bands or using the guest network solves it. And 16 A is the relay’s limit, not the circuit’s: a 2 kW fan heater draws 8.7 A at 230 V and is fine, a 3 kW one is not.
Schedules that pay for the hardware
Do the arithmetic before setting anything. A 20 W set-top box switched off for 16 hours a day saves 0.32 kWh daily, which is 117 kWh a year — about BDT 1,000 at a domestic tariff near 8.5 taka per unit. One plug, two years to break even. Not compelling on its own.
Group the devices instead: set-top box, console, printer, soundbar and television add up to roughly 40 W. Cut that for 16 hours and you recover 234 kWh a year, around BDT 2,000, and the plug pays for itself in about ten months. Set one window at 01:00 off, 17:00 on and add a second if the house is empty during the day. In the Tapo firmware the schedule lives in the plug’s own memory, so it keeps firing through a router reboot or an internet outage; only app control and voice commands need the cloud. And never schedule an off-window for anything that records overnight. If timers are new to you, the wider set of tricks in cutting an electricity bill with smart plugs and timers covers lighting and water heating, where the savings are larger.
Four sockets that must never be on a timer
- Router and ONT. Cutting them kills broadband and usually the landline, and a plug that needs Wi-Fi to be switched back on is a trap you set for yourself. The power-cut workarounds in keeping internet working through a power cut are the better answer for that socket.
- Fridge and freezer. A four-hour gap pushes the compressor’s contents past 4 °C, and spoiled food costs more than a decade of standby.
- Medical equipment. CPAP machines, oxygen concentrators, and anything whose battery must stay charged.
- Appliances mid-cycle. Washers, dryers and dishwashers with mechanical dials forget where they were; killing power at the wall can leave a drum full of water.
Add alarm panels, doorbell transformers and gas detectors to that list. Keep one plug free as a roaming meter and move it each season — the device drawing 20 W today is often the one that leaves the house next year, and the saving leaves with it.