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Vampire power - a trick to help you work out the costs

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There has been a lot of talk in the media recently about the amount of energy some electrical items in a home when they are simply 'sitting plugged in doing nothing'.

It has been nicknamed vampire power with some very alarming costs quoted at times which may worry people unnecessarily. It is also traditionally known as Standby Power.

If you are not technically minded understanding how much this vampire power is costing you for a particular electrical gadget in your home is impossible.

But, how WARM a gadget gets when it is not being used is a direct clue as to how much energy it is wasting. The warmer it is the more it is costing you.

This article has some practical examples of vampire power for physically small items in my own home and how much energy they are wasting. This could help you do similar comparisons on your own gadgets to work out roughly how much they might be costing you if they are left switched on permanently.


Unless you have a special plug in energy measurement device or smart monitor plug it is impossible to know by looking at an electrical item or even looking at the labelling how much vampire energy it is wasting.

But, one very useful thing about wasted vampire energy is that it is always wasted in the form of heat. Simply by touching an item and feeling how warm it will give you a very good idea whether it is costing you a little or a lot.

If an item basically feels cool to touch then it isn't using any energy, or such a tiny amount that you would never notice it on your bill.

Below are some real world examples from my own home, where I do the best to describe how warm something feels to me, along with how much vampire power I have measured for that gadget.

The first examples I will give are will the smallest items, small plug in power adapters and chargers which are everywhere in modern homes.

Example 1

The first example below is slightly warm to to my finger-tips. The best way to describe how warm is chocolate would slowly melt touching it. There might be better ways of trying to describe how it feels but I'm afraid can’t think of anything better. Sitting there all year would cost about £2.50 in electricity to generate this 'finger-tip heat'.

Power socket adapter plug vampire power
The front would very gently melt chocolate! £3 a year

Example 2

With this mobile phone charger I can feel just a tiny amount of warmth coming on one small part of the front face if I hold my fingers on if for a few seconds. This uses around 40p a year to run with nothing charging on it.

Mobile phone charger vampire power
Tiny amount of heat just in the area of my finger tips 50p per year

Example 3

This is plug-in adapter where the body of it all feels evenly warm all over, warm enough to happily warm a cold hand up nicely if I had just come in on a cold day - this ‘toastier’ device uses around £5 of electric a year.

Power adapter vampire energy
Warm for a chilled hand on a cold day £7 a year

Example 4

Modern laptop power adapters are actually very good (very cool once a laptop is fully charged) and the worst I have found is 80p for a year. Older ones might not be as good. The modern ones are basically cold bricks. Even plugged in to a fully charged laptop that is switched off they stay cold. So these are really good for vampire power.

Laptop charger adapter vampire power
Modern ones are basically cold bricks, so max £1 a year

Larger gadgets

The touch test is useful for any small electrical item although the bigger you get the harder it gets to use this method. This is because for gadgets with larger boxes (especially for example TVs, the electronics that is generating the heat is buried somewhere deep in the product and it is probably impossible to feel on the outside.

One good larger example to show here is my router. The router box itself is pretty warm to touch across the full palm of my hand, so quite warm across quite a big area compared to the other items. If I came in on a cold day with chilled hands this would warm my hand up pretty nicely. The vampire energy to generate this heat costs me about £16 a year in electricity to run.

Internet home wifi router vampire power heat waste
Toasty and warm all year round for £20

Other slightly larger items that this type of touch detective test might work for are:

- Sky boxes

- Blu ray and DVD players

- games consoles

- under sink instant hot water dispensers

Anything electrical and small (ish) that is warm sat there doing nothing is telling you something.

Hopefully all the above might help you suss out which are the most important things to switch off at the plug and how much difference it really will make.

All costs above assume a 27p unit cost of electricity from October 2023.


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All content on the site should be treated as information and not advice. You should take professional advice where appropriate to different site articles.


Mark Thompson

Get Energy Savvy - simple practical home energy efficiency information


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