Does leaving appliances on standby actually cost much?

Standby power gets far more attention than its share of a bill deserves, and the reason is historical. Devices sold in the early 2000s could draw ten or fifteen watts doing nothing, and the phrase entered the national conversation then. Ecodesign rules have since capped standby at a fraction of a watt for most equipment, with a slightly higher allowance for devices that need to maintain a network connection. The result is that the advice outlived the problem for most devices, while a small number of genuinely thirsty items still sit quietly in living rooms.

What you'll need

• A plug-in energy monitor, if you want real numbers (optional)
• Your electricity unit rate from your own bill

Step by step

1. Do the arithmetic once so the scale is clear.A device drawing one watt continuously uses about 8.8 kilowatt hours a year. Multiply that by your own unit rate to get its annual cost. Then do the same for five watts and for fifteen. That single exercise tells you which of these is worth acting on and which is not.
2. Accept that most modern devices are genuinely small.Chargers with nothing attached, modern televisions in standby, smart speakers, most kitchen appliances with a clock, and modern set-top boxes generally sit between a fraction of a watt and a couple of watts. Individually these are pence per year, and switching them off has more symbolic value than financial.
3. Find the specific exceptions, which are worth real money.Older set-top boxes and PVRs, especially those that stay awake to record. Games consoles left in instant-on or rest mode, which can draw ten watts or more continuously. Hi-fi amplifiers and AV receivers, some of which draw significant power in standby. Older desktop computers and laser printers. Anything with a permanently lit display or a mains transformer that is warm to the touch.
4. Use the warm test as a first pass.A power supply or device that is noticeably warm while doing nothing is turning electricity into heat, which is exactly what standby consumption is. It is a crude test and it finds the worst offenders quickly.
5. Measure the candidates with a plug-in monitor.A cheap plug-in energy monitor shows the actual draw and, over a week, the cumulative kilowatt hours. It converts a general belief into a per-device number, and it usually produces one or two genuine surprises alongside several anticlimaxes. Some libraries lend them.
6. Put the answer in proportion against what actually uses electricity.Total household standby in a typical modern home is a small fraction of the bill. The tumble dryer, electric heating, hot water, the oven and the kettle dominate. Optimising standby while ignoring those is the classic misallocation of effort.
7. Act on the few that justify it, in the easiest way.A switched extension block behind the TV, an accessible wall switch, or a smart plug on a schedule for the AV stack. One action that covers several devices is more likely to persist than a nightly round of the house.
8. Change the settings rather than the switch where you can.Turning off instant-on or rest mode on a games console, disabling quick-start on a television, and setting a printer's sleep timer all reduce the draw permanently without anyone having to remember anything. This is usually the better fix.
9. Leave alone the things that must stay powered.Fridges and freezers, alarms, the router if anything depends on it, smart heating controls, telecare and medical equipment, and anything with a defrost cycle or an internal clock that matters. The saving from switching these off is trivial and the consequences are not.
10. Be honest about the result.For most households, dealing with standby properly saves a modest but real amount per year, concentrated in two or three devices. That is worth doing, and it is not the answer to a large bill.

Tips

• One watt continuous is about 8.8 kilowatt hours a year. Memorising that single figure lets you cost any standby claim you ever read in a few seconds.
• The games console in rest mode is the most commonly overlooked genuinely thirsty device in a modern home. Check its power settings before anything else.
• A switched extension block behind the television turns five devices into one switch, which is the difference between a habit that lasts and one that does not.
• If a phone charger is cool to the touch with nothing plugged into it, it is drawing almost nothing. The old advice about unplugging chargers is largely obsolete.

Common mistakes

• Assuming standby is a large share of the bill — It was in the early 2000s, and ecodesign rules have since capped it for most equipment. In a modern home it is a small fraction, and treating it as the main saving means ignoring the heat-producing appliances that dominate.
• Switching everything off at the wall on principle — It achieves little for most devices and causes real problems with a few — fridges, alarms, routers, smart heating and anything with a clock or a defrost cycle.
• Guessing which devices are the thirsty ones — The intuitive candidates are usually not the real ones. A plug-in monitor for a week identifies them properly and stops the effort going in the wrong place.

Questions people ask