Does power also flow through devices and TVs when they are turned off or on standby?

Answer

A lamp is a simple thing: when you open the switch, the circuit is broken and no more current can flow. There is therefore no energy consumption (be careful, this does not mean that you can just touch all contact points. It is possible that you unconsciously close the circuit with your body via the ground and that a current flows through your body).

Something different are all those devices that are ‘supposedly’ switched off, but can still be brought to life by pressing the remote control. You immediately understand that these devices cannot be ‘off’, but constantly watch until they discover a signal ‘on’. That in itself would not be a big problem, but those devices usually work at a low voltage. Therefore, a transformer is needed to convert the 240V from the grid to that low voltage. Such a transformer will always waste some energy, even if it is not loaded. Just plug the transformer of your mobile phone into the mains, WITHOUT attaching your mobile phone to it: the transformer actually does nothing, but you will notice that it gets a bit warm after a while. This is a very small energy consumption, but in the last ten years an enormous number of these devices have been added. And many little ones…

Attached is a figure showing the increase in this creeping energy consumption over the past few years.