You might think that when you switch an electrical appliance off, it uses no power, but you could not be more wrong. Many appliances now have a ‘standby’ function that allows them to be turned on again quickly, without starting up from scratch. The appliances that have a standby facility tend to use electrical power when they are apparently off. Some use more than others.
The worst culprits are appliances that have black cubes in their power lead, between the appliance and the plug. This is responsible for converting AC electricity into DC electricity and the sensors and circuitry inside this box need to monitor what is happening with the device more or less constantly. This uses varying amounts of power, depending on what type of appliance it is, how old it is and the way it has been designed.
What Appliances Use Stand by Power?
A very wide range – anything that has an LED – such as a washing machine that is still on after the washing cycle has finished. Something that has a display that is always on – like the clock on a microwave or standard oven. Anything with the black box power supply often called a ‘vampire’, between the appliance and the plug. And anything that has a remote control. Worryingly, some equipment that has none of these things and shows no signs of using any power still has a standby function and burns up quite a few extra watts of power when you think it isn’t doing anything. The only way to tell is to buy a meter to measure energy usage.
How Much Power Does Standby Use?
It varies between different pieces of equipment but the major problem is not each individual device. It is the cumulative effect of all the appliances that we all have in our homes that may be using electricity without us knowing. It is easy to have about 50 such appliances (scary – but just count them up…) and each one may only be using £3 of power per year – but that is £150 per year for all of them, which is quite a sizeable sum for pieces of equipment that are doing nothing.
How Can I Save Standby Power?
This is quite tricky but with a few simple steps it is possible to reduce overall standby power usage by about a quarter. Unplugging equipment that is not in use regularly (in case you forget and leave it in standby for weeks at a time). Using multi-plus with switches, so that you can disconnect everything at once. Use a power adaptor that takes several appliances, and switch them all off at once when you switch the unit off. Don’t leave mobile phones charging once their charge is complete – and turn off the empty charger. Buy low energy standby appliances – its getting easier – but you will need to do your research before selecting your appliance.
How Much Does Standby Power Cost the UK?
This is very difficult to measure accurately, but the overall percentage of all domestic electricity used probably uses around 15% for standby functions. Having appliances on standby may account for about one hundredth of all carbon dioxide emissions released into the atmosphere globally.
What are Some Examples of Standby Power?
A mobile phone charger, plugged into a fully charged phone uses 2 watts (1.8p per month) – a phone that is charging uses 3 watts (2.7p per month), so there is not much difference. Just having the power supply plugged in, without any phone, uses 0.25 watts. A computer display in full use gobbles up 65 watts (68p per month) – but still uses 12 watts when in sleep mode (10p per month). When off it uses 0.8 watts (<1p per month). Some laser printers actually uses more power in standby mode – 6.4 watts on ready and only 6.1 when fully on. A cordless phone uses 2.8 watts when the handset is in place and ready to use, but only 1.9 watts when you are actually on the phone.
Some of these are relatively small sums but if you add them up throughout a typical household there are large savings to be made on an annual basis by turning appliances off (or unplugging them) rather than putting them into standby!