Energy saving tips often include advice to avoid leaving gadgets on standby and chargers plugged in when not in use.  But how do you know how much energy they use? Even if you have an OWL type energy monitor attached the power supply, these items will not register. One way is to use a plug-in power and energy monitor. This is a device that plugs into the mains and into which you plug the gadget.

When we checked our gadgets back in 2005, we found that the worst culprit was an early 1990s music system which ticked over at around 14 watts in standby mode. As we hardly used it anyway, it got switched off at the mains (a saving of around 122 kWh per year and approximately £15).

We recently ran another check on the gadgets and chargers in use in our home. Some of the results surprised us.

Calculation: If we left the 5 watt standby radio switched on at the mains plug and not in use for 21 hours a day (we typically have the radio on for 3 hours a day), how much energy would we waste in a year?

We did this in a spreadsheet for all our gadgets!

Below the radar

Chargers, standby and digital radio power supplies