Standby power, in honest proportion
Short answer. Modern standby power is far lower than the advice suggests: a television draws about half a watt on standby, or roughly 4 units a year. The devices that still matter are the ones that run continuously by design — routers, dispensers with heated tanks, and an idle UPS — not chargers left in sockets.
Applies: All year · Cost to do: Costs nothing · Indicative saving: around 15 units a month
The advice is twenty years out of date
Standby consumption of five to ten watts per device was normal in the 1990s and early 2000s. Regulation and better power supply design have cut it to well under a watt on most current equipment.
A television on standby all year costs about 4 units. The same television being watched costs about 170. Telling somebody to unplug it is technically correct and practically a distraction.
What genuinely still costs something
A Wi-Fi router and fibre ONT drawing 15 watts between them run 8,760 hours a year — about 130 units. That is more than a microwave or a blender contributes, and it is invisible because it never switches off.
A water dispenser's hot tank maintains temperature all year whether or not anyone uses the hot tap. Switching that function off, using the switch on the back panel most households never touch, is often the largest 'standby' saving available.
An idle UPS or inverter loses 15 to 40 watts continuously whenever it is switched on. During long stretches with no load shedding, switching it off entirely is worth several units a month.
Set-top boxes and older satellite receivers remain genuinely bad, drawing several watts continuously on some models.
Where to spend the attention instead
The ranking is not close. The geyser switch is worth 400 units a month in winter. The air conditioner thermostat is worth 120 in summer. LED conversion is worth 100 year-round. Standby across an entire house is worth perhaps 15.
Do the standby measures because they are free and take five minutes, not because they are where the bill is.
The safety argument, which is separate and stronger
Uncertified chargers and cheap power adapters do fail, occasionally dangerously. Unplugging those is worth doing for that reason alone.
That argument does not depend on the electricity saving, and it should not be dressed up as one.
What to actually do
- Switch off the hot tank on a water dispenser if nobody uses the hot tap.
- Switch the UPS off during long periods with no load shedding.
- Switch off mesh Wi-Fi nodes covering rooms nobody uses.
- Put set-top boxes, speakers and printers on one switched strip.
- Unplug uncertified chargers — for safety, not for units.
- Then stop, and go and put the geyser on a timer.
What does not work
- “Phone chargers left plugged in waste significant electricity.”
- A modern charger with nothing attached draws under a tenth of a watt — under 1 unit a year. The fire-safety argument for unplugging cheap ones is much stronger than the energy one.
- “Unplugging the television at night makes a noticeable difference.”
- About 4 units a year. It is real and it is negligible next to what watching it costs.
Frequently asked questions
Should I turn my Wi-Fi router off at night?
Eight hours off a day saves roughly 2 to 3 units a month. That is real, and for most households the reboot time and the interruption to overnight tasks outweigh it. Switching off unused mesh nodes is the better version of the idea.
Does a UPS increase my bill even when there is no load shedding?
Yes, through standby losses of 15 to 40 watts whenever it is switched on. And when it is used, it adds 20 to 35 per cent to every unit you consume during an outage through charging and conversion losses.
Related guides
- Converting a house to LED, in the right order — all year, small one-off cost
- Refrigeration: the load that never switches off — all year, small one-off cost
The numbers behind this
All 10 guides are ranked by value in the index. To see what your own house needs, run the efficiency audit.