So what is the answer to our initial question – is it true that electronic equipment consume a lot of power when they are on their standby mode and presumably turned off?

The answer is: it depends on the equipment.

From what we’ve seen on our own (and small) research, the majority of equipment won’t be consuming anything at all when they are on their standby mode, or be consuming so little that is negligible – turning them off by removing them from the wall would have an impact of less than $1 on your monthly electricity bill.

But there will be equipment that will really consume a lot of power and our greatest villain was our cable TV converter, consuming 27.5 W when it is presumably turned off! Having this equipment connected 24/7 to the wall as it happens on the majority of homes – and with some homes having more than one converter box – will definitely make an impact on your electricity bill.

Remember, however, that if your cable signal is digital by removing your cable TV converter from the AC outlet you will lose access to the programming grid. When turning the equipment back on you will have to wait to up half an hour for it to download all channel information.

So almost all equipment won’t be consuming anything at all but because of just one of them you may have an increase on your electricity bill.

The main problem is how to know which equipment consume power when they are theoretically turned off. The best way would be buying (or borrowing from a friend) a digital power meter and make the measurements for yourself. Assuming that you don’t want to buy one or don’t have a friend that has one, another option is the temperature test: any equipment that is hot when it is turned off is consuming power. So just touch all sides of your equipment to check whether they are hot or not. Of course this shouldn’t be done after you used them, as they will be hot exactly because you have just used them. Try doing this in the morning, before anyone starts using them.

Or you can simply use the paranoid approach: remove all equipment from the wall (connecting them to a surge protector and turning off the surge protector) after using them!

We also made two important discoveries during our research.

First was regarding our computer speakers. When idle, i.e., with no sound being produced, it consumes 7.5 W. So it is not only important to turn it off after using the computer (a lot of people forget to turn them off), but also while you are using the computer try keeping them off when you are not using sound (i.e., not listening to music, not playing videos, not playing games, etc). The second discovery about our speakers was that they are consuming 3.3 W even when they were turned off!

The second major discovery was regarding our laser printer. Leaving it on its “ready” (idle) state consumes 2.1 W, but it is better to leave laser printers turned on than turning then on and off all the time, as every time we turn them on they start a heating process and paper jamming detection that consumes around 300 W. This is the only case which leaving an equipment on its idle state and consuming a little bit of power is a good thing – unless, of course, you won’t be using the printer for the whole day; then leave it off.