Standby for Action!

Leaving electrical appliances in “standby mode”, rather than turning them off at the wall, has long been cited as waste of electricity. Statistics about how many power stations we could decommission if we all turned off our TVs are often in the press, but usually with little substance to back these claims up. Sustainable Girton have been measuring some typical household appliances to see how much they really use in standby, how much you could save if you turned them all off, and how this relates to other energy saving measures.

We measured a number of appliances that are commonly left on or in standby. While your particular model of TV might use more or less than these, our results should give you a rough idea of how much power is involved, and should you want to measure your own devices we’d be happy to help.
Device                                    Standby (Watts)   On (Watts)

Hi-fi/Stereo                                    12                           22

TV                                                 10                          100

Video recorder                               1                            13

DVD player                                    7                            12

Digital TV set top box                     5                            6

Computer + peripherals                  15                          130

Computer monitor                          11                          70

Laptop computer                           2                             29

Broadband modem                        14                           14

Answering machine                        3                             3

Battery charger                              2                             14

Mobile phone charger                    1                             5
Total:                                           83 Watts                418 Watts

This comes to a total of 83 Watts in standby which if left running all year amounts to a cost of about £75: 83 Watts for 24 hours a day, 365 days a year is 727 kWh (units of electricity) and each unit currently costs about 10p. This is not an insignificant sum by any means, and so it is clearly financially beneficial to turn things off.

Environmentally speaking, the generation of this electricity will result in the production of over 300 kg of CO2 each year [1]. To give you an idea of what this means, it is roughly equivalent to the pollution produced by driving 870 miles in a typical car [2] (i.e. just over two miles per day), or about 10% of the pollution from the average person’s annual electricity and gas use [3].

There are clearly bigger ways to make a difference to the amount of energy you use — avoiding one short car journey per day for example — but cutting out the wasted energy of appliances on standby is an easy change to make. It really surprised us how much some appliances use, and how much this adds up to when left on 24 hours a day, 365 days a year.

Businesses can also help by becoming more energy efficient and making a saving along the way. Business Utilities UK, a commercial energy broker, have worked with us to try and cut their usage by remembering to turn off devices (such as printers etc) after staff have left the office.

[1] This is calculated taking account of the various different ways in which electricity is generated in the UK, and the various sources of inefficiency such as transmission losses, using the National Energy Foundation’s calculator. Each kWh of electricity generates 0.43kg of CO2. 727 kWh * 0.43 = 313 kg.

[2] Using the same calculator, you can compare different fuels. Each mile in a typical car generates 0.36 kg of CO2. 313 kg / 0.36 = 868 miles.

[3] Using Carbon Footprint results, the average UK consumption of domestic fuels (i.e. the total for the home, water heating, cooking and electrical appliances section) is 2.8 tonnes of CO2. 313 kg is a little over 10% of this.