Where the electricity goes when everything is switched off

Both approaches to standby power consumption work. What differs is what they cost you, and the cost is what this sets out.

Off is usually a low-power state

A device that responds to a remote control must keep an infrared or radio receiver alive and a processor ready to interpret it. A device with a network connection must maintain that connection and respond to network traffic, which costs continuously.

A device with a clock, a memory of your settings, or a fast-start feature is doing work while apparently off. True zero consumption requires a mechanical switch that physically breaks the circuit, which is increasingly rare.

The offenders are not the obvious ones

Set-top boxes, games consoles in quick-resume modes, network equipment and some televisions with fast-start enabled are typically the largest. Phone chargers left plugged in with nothing attached draw very little on modern designs, despite being the folk example.

Anything with a display, a fan or a mains transformer that is warm to the touch when idle is consuming meaningfully. Warmth is a decent first-pass diagnostic because all standby consumption eventually becomes heat.

Regulation has done most of the work

Several jurisdictions have imposed standby limits on devices sold there, and typical consumption has fallen substantially as a result. Those limits often carve out networked devices, which are exactly the category that has multiplied.

Under load, the result is that individual devices are much better and household totals have not fallen proportionally. Exact limits and covered categories vary by country, so check local regulations rather than assuming a figure.

Measuring beats guessing

An inexpensive plug-in energy meter reports instantaneous power and accumulated energy, which turns speculation into data in a few days. Measure over a period rather than at an instant, because many devices cycle between states. Multiply average watts by hours per year and by your tariff to see whether any given device is worth acting on.

Most households find that two or three devices account for the majority of the total.

Switching off has costs too

Devices that must reboot, resynchronise or reconnect on power-up consume energy doing so and inconvenience the user. Some equipment, notably network gear and anything with a hard disk, is stressed by frequent power cycling.

Devices that update firmware or content overnight need to be reachable to do it. The sensible approach is to switch off the large idle consumers you rarely use rather than everything indiscriminately.

Figures here are typical rather than guaranteed — check the spec sheet for your part.

Where the bigger savings actually are

Standby is a real but modest share of a typical household bill compared with heating, hot water, cooling and cooking. Fixing standby is satisfying and cheap; insulating and adjusting heating settings usually saves an order of magnitude more. Both are worth doing, and it is worth being honest about the relative sizes.

A device left running rather than in standby, such as a computer overnight, dwarfs any standby figure.

Side by side

The takeaway

Measure the few large idle consumers rather than unplugging everything. Two devices usually explain the total.

Understanding the failure mode tells you more than the feature list does.