Photo of Terence Eden. He has a beard and is smiling.

No, you can't save £30 per year by switching off your "standby" devices

· 21 comments · 950 words · Viewed ~21,829 times.

Every few years, a dodgy stat does the rounds claiming you can save £££ if you switch off all your gadgets at the wall. The standby mode of your TV is bleeding you dry!!!

This is known as "Vampire Energy" and, amusingly, is a bit of a Zombie statistic. Being the party-pooper that I am, I emailed the Energy Saving Trust to ask how they calculated the stat. They replied quickly with:

The calculation for £35 savings from turning off stand-by devices per year per household comes from average 201KWh for stand-by power times GB average standard electricity price 16.471 £p/KWh, then rounded to nearest £5.

201KWh comes from “Further Analysis of the Household Electricity Survey Early Findings: Demand side management”.

Please note that the term “stand-by” used in this situation also include device on idle mode.

Please refer to the report in more detail about the assumptions used in the analysis. Here is the link for this report: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/275483/early_findings_revised.pdf

OK, let's take a look at the 2013 report.

First up, what disclaimers do they have? We developed an algorithm to determine standby power consumption by inspection of the profile of energy use, from the two-minute interval data (see Appendix). Overall we found that standby power accounts for an average for all 250 households of 23 W, continuously. This works out at a mean of 201 kWh/year, or 5.1% of total electricity. Readers should note that the minimum reading from monitoring equipment is 0.01 Wh, so an appliance drawing 1W only gives a reading every six minutes. We configured the algorithm to register power as low as 0.025 W, which gives a reading only once in four hours. However, it is often impossible to distinguish a difference between off and very low standby power. This means we were unable to determine a reliable figure for many appliances – especially for TVs and some other AV equipment. The mean standby figures we report here could be biased, and higher than the real figures.

Straight away they say that it's hard to measure low power devices - so they've been rounded up. But at least they're honest about their methodology.

So, what devices did they monitor?

Chart showing how much power various devices use in standby.

I'm not sure how many people were still using VCRs back in 2013 - Dixons stopped selling them in 2004. I'd bet hardly anyone uses them now. If you still use one - please switch it off at the wall when not in use!

Set top boxes still exist - but most TVs now have digital decoders built into them. When the TV is on standby, the "STB" is also on standby. Drawing a tiny amount of electricity. But, OK, not everyone has a new TV.

What about things like Sky boxes? Well, the report mentions two issues:

Many TVs now have digital decoders built in and do not need a separate set top box. However, in this survey more than half the TVs also had set top boxes (232 set top boxes for 407 TVs), and another 25 had a Sky box. Sky boxes and other set-top boxes (many types, including Virgin media) use significantly more ‘standby’ power than other audiovisual appliances. However, strictly speaking set top boxes and Sky boxes do not have a standby mode, because they are always active to some degree. We have included them in our analysis because they contribute in large part to the overall ‘standby’ of an audio visual site. Also some boxes consume a great deal less in idle mode than others, suggesting there is scope for improvement.

Yes, you can switch these boxes off at the wall - but then they won't record the programmes that you want.

In March 2013 Sky announced a software update for some of their decoder products, introducing an option for a new eco-standby mode using only 0.5 W. This option is not on by default. In addition, the eco mode only activates overnight and if there are no recordings scheduled. (Wake up takes approximately 1 minute.) This is a positive move but the impact will be small unless householders are made aware of it and take the trouble to activate it. TV standby power is generally lower than the set top boxes and shows some signs of falling over time, with newer devices using less power in standby mode on average.

As the report was being published, Sky updated their boxes so they'd be eco-friendly. I'm told that this mode is now the default - but it may be worth checking to see if your devices have an "eco" setting. That will do more good than unplugging things.

It's not just AV equipment contributing to this "vampire" power. Computer equipment is also included:

Chart from the report showing various bits of IT equipment and their power use.

Again, the report acknowledges that things like modems and routers don't really count as "standby" because they can be in constant use. If you want to check your TikTok in bed, you don't want to have turned off the WiFi.

Laptops have a high average "standby" because they use the first few hours charging their batteries. So, again, legitimate use rather than "vampire" use.

The report also looks at things like microwave oven clocks, tumble-dryers, dishwashers. Some of these do use a considerable amount of standby power. Although resetting the clock on the microwave every morning may not be the best start to your day.

That all feeds in to the 201kWh per year figure.

There's also some discussion about the idle power for things like doorbells, smoke alarms, burglar alarms. They have a significant power draw - but I don't think anyone would suggest that it is sensible to switch off your alarms overnight.

Remember that original Tweet?

It suggests turning off tablets - which are not included in this report. Go buy a cheap Watt-meter and see how much "vampire" energy it is using. Once the battery is fully charged, it will use very little.

Similarly, laptops - even older ones - won't draw too much electricity once they've gone to sleep.

Consoles? Sony publishes stats for the PlayStation. Some of the older ones will use up to 4W in "rest" mode. That allows the device to check for updates and to power on quickly. If you switch it to low-power mode, it'll use less than a Watt.

This "advice" is bunkum.

Should you switch your devices to "eco" mode? Absolutely! Will it save you £30? Not even close.

Update - 27th April 2022

This zombie stat is doing the rounds again today. Here's a Twitter thread where I go into a bit more detail about it.

Share this post on…

  • Mastodon
  • Facebook
  • LinkedIn
  • BlueSky
  • Threads
  • Reddit
  • HackerNews
  • Lobsters
  • WhatsApp
  • Telegram

21 thoughts on “No, you can't save £30 per year by switching off your "standby" devices”

  18. Manek Dubash says:

    I find one way of quickly getting a handle on how much juice a device is consuming is the Mk 1 hand. Is it warm? If so, it's using enough energy to consider doing something about it, if not, it's not.
    Reply

  19. Gordon says:

    All this ignores a major factor; the energy consumed by these devices is radiated as heat into your home. If you have thermostatic control of your rooms/house then that heat will contribute to the thermostat switching off just a little sooner, or going on later, a little more often. In that way, the energy is not 'lost' or 'wasted', it is just added to the energy used to heat the home. If we consider a house to be a closed system (it's not, but leaving your Sky box plugged-in doesn't change that), then the net effect is...close to zero. Yes, it may be more efficient for many to use gas to heat rather than electricity, but at the volumes we're discussing this would be a rounding error in overall household consumption.
    Reply

Trackbacks and Pingbacks

What links here from around this blog?

  1. Chart from the report showing various bits of IT equipment and their power use. No, you can't save £30 per year by switching off your "standby" devices
  2. Screenshot of an email. It says "Hi Terence, You'll earn 1800 OctoPoints – that's £2.25 worth – for every unit of electricity you cut down between 5:00 PM and 6:00 PM on 15th November. Opt in now to save power and earn rewards in this Session. You'll go into a draw to win an extra 400,000 OctoPoints – that's £500 worth! – just for opting in. Important: you need to opt in before the Session starts if you want to earn rewards." Experiments with domestic load shedding in the UK

Comments closed