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Always unplug the charger from the power outlet!

Do you also always leave the cell phone charger in the socket when you leave the house? Then you’re wasting electricity unnecessarily – and money. But the charger is definitely not the only hidden power guzzler in your household. atechbook asked an expert how devices in standby mode affect your electricity bill.

Any charger that is constantly plugged in is like a dripping faucet. The reason for this is the transformer, which also consumes power in standby – even when no end device (for example, smartphone, tablet or laptop) is plugged in. The transformer takes care of converting the voltage from 230 volts to the necessary level.

How can I tell if a device is consuming power in standby?

To test whether a charger is eating up power in standby, all you have to do is touch it: If it’s warm, current is flowing. Often, chargers with higher power also emit an electrical buzz that also indicates current flow. Incidentally, the same also applies to the chargers of electric toothbrushes, shavers and cameras as well as laptops or PCs.

Although the power consumption of these devices is basically not high, a year has almost 9000 hours. Thus, for every forgotten charging cable, several kilowatt hours accumulate senselessly. In addition, some batteries can be broken by overcharging.

Disconnect unused devices from the mains

To save electricity, electronic devices should not be left on standby for long periods of time. This is also advised by Jens Hakenes, editor beico2onlineGmbH . “Unused chargers or other power supplies should always be disconnected from the mains, either by pulling the plug or by using a power strip that can be switched off. There is also an energy-saving mode on most cell phone models. If this is activated, the battery will last longer. Even better, turn off your phone when it won’t be used for a long time.”

How much money can I save?

Cost of one kilowatt hour (kWh) still cost 32.16 cents on average in 2021, the average electricity price in Germany will already be 41 cents per kWh in 2022. Electricity is therefore becoming more and more expensive. All the more reason to look out for hidden sources of consumption in the household.

“As a rule of thumb, the newer the charger, the more economical it is. Since 2014, chargers and other power supplies should comply with an EU regulation. This stipulates that power supplies with up to 51 watts consume only 0.3 watts in idle mode. Such a charger consumes 2.4 kilowatt hours per year and costs 0.98 euros (assuming 22 hours of idling per day). According to the Federal Environment Agency, idle consumption of around 5 watts is also possible. That would be 40 kilowatt hours or a good 16 euros per year,” Hakenes says.

That doesn’t sound like much at first glance, but in most households more than one charger is in operation in standby and eats up power unnoticed. So consumption adds up quickly.

Hidden standby devices in the household

Nowadays, hardly any household appliance can do without electronic control. In the past, everything was technically simpler, as electrical appliances had real off switches that completely disconnected the device from the power grid when “off”. This is still the case, for example, with tower PCs, which have a large I/O switch on the back of the power supply unit. In contrast, many electrical devices today have only “sham off” switches or push buttons that conceal electronics that consume power throughout. These include, for example:

  • Television
  • Radio
  • Receiver
  • Printer
  • Game console
  • Microwave oven
  • Washing machine
  • Tumble dryer
  • Dishwasher
  • Stove
  • Coffee maker

The reasons why the devices constantly consume power in standby are quite different. Some permanently display the time. Others are constantly ready to receive signals from a remote control, because only then can they be switched on at any time from the comfort of the sofa. In the case of coffee machines or photocopiers, on the other hand, which have to be heated up first, the aim is to ensure that they are ready for immediate use.

On average, standby consumption accounts for one tenth of the electricity bill. Older devices in particular often consume more electricity in standby mode than new ones. Hakenes: “An old stereo system, for example, can cause unnecessary costs of almost 35 euros per year.”

Here’s some examples of how much power appliances consume on average in standby mode:

Device Standby watt
Kilowatt per year* Euro per year*
Stereo system 15 120 49,20
Television (LCD) 14 112 45,92
Mini hi-fi system 11 88 36,08
PC, monitor & printer 10 80 32,80
DVB-T2 receiver 10 80 32,80
Router (DSL/WLAN) 8 64 26,24
Cell phone charger (old) 5 40 16,40
Telephone (cordless) 3 24 9,84
Washing machine 3 24 9,84
Microwave oven 2,5 20 8,20
Cell phone charger (new) 0,3 2,4 0,98

(Source: *Average standby time per day: 22 hours; measurement of individual sample devices

Tip: Simply switch off standby

Use a power strip with a switch for standby devices. This allows several devices to be disconnected from the power supply at the same time without having to pull the plugs out of the socket.