How much does it really cost you to leave your tech on standby?

The high cost of energy and the resulting media coverage has led to some questionable advice on how much you can save.  

Turning off your larger tech products can seem like an easy win. Flick a switch on the socket and you're saving money. We can't argue with that.

But, thanks to our tests, we know the savings could be so small that it may not make much of a difference to your energy bills. We’ve used the most recent price cap figure of 22.36p per kWh and created averages from tested models - including TVs and soundbars - so we can share with you how much your tech really costs to run. 

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Cost of tech on standby

In the table below, you'll find the average annual standby energy costs for a device on standby for 20 hours per day (that's 7,300 hours per year).

Turning all of this tech off at the wall will save you £20.40. Every little helps when you’re grappling with high energy bills, but it’s a far cry from some media reports claiming you could save £15 a year by turning off your TV alone.

Find out how you can get the best energy deal

Can you save with a smart plug?

There’s a convenience to standby mode. Devices turn on quicker and stay up to date in the background, so they’re ready to go when you are. Turning devices off at the wall will save you some money, although it’s not always practical – plugs can be hard, or impossible, to reach for some.

Smart plugs enable you to switch devices on and off remotely, using an app on your phone. 

A smart plug on standby should use less power than the devices attached to them - 20 hours per day on standby will cost you 97p. This is less than everything bar a TV and Blu-ray player, based on our tests.

However, there's a catch. The cheapest smart plug we've tested is £8.99, but some can cost over £40. This means it could take years before a smart plug pays for itself in energy saving alone.

Connecting a smart plug to a smart speaker would be the most cost-effective way to use one, but it would still take a year before your energy savings match the initial cost of the plug. If you bought the most expensive plug, it would take more than seven years.

So while smart plugs can make life more convenient, they're not the best way to save energy. Unless, that is, you buy one with an integrated energy monitor. This lets you keep an eye on how much electricity your appliances are using, so you can adjust your usage.

The TP-Link Tapo P110 is the cheapest smart plug we've tested with energy monitoring that we're happy to recommend:

See more on how to buy the best smart plug, or head straight to our smart plug reviews to compare prices and models.

The cost of charging your laptop and phone

Since laptops and phones are battery-powered, their power consumption is measured slightly differently. Our team of experts carried out a separate snapshot test on four laptops and four phones using a power meter. These start from £20 and are widely available, so you can buy one yourself if you want to test your own gadgets and appliances.

We used the RS PRO energy meter, £28, from RS Components. If you're interested in measuring your mobile phone or other appliances around your home, you can buy similar meters starting from around £18 from popular retailers such as Amazon and Screwfix.

The good news is that your phone and laptop don't cost too much to charge.

Phone

• Even the most expensive way of charging a phone - leaving it plugged in over night - only costs £1.43 per year. This is based on charging every night
• We found the cheapest method is to put it your phone on charge when it's at 30% battery and charging it to 80%. This will save you 42p per year
• For more information, see can changing the way you charge your phone save you money?

Laptop

• Leaving your laptop plugged in 24/7 will cost a little more -  £6.22 per year, which is only slightly more than the standby cost of a wireless speaker
• If you charged it only when needed from 30% to 80% (based on using the laptop for five days per week), you could save yourself the princely sum of 72p a year. This way is better for your battery health, too
• For more information, go to can you charge your laptop for less?

Our expert tests will help you find the best laptop to suit your needs, whatever your budget

The tech you shouldn't switch off

One device to leave on is your wireless router. It may seem like an obvious choice for a night-time switch-off, but the eight-hour drop could look like an unstable connection to your internet service provider and can lead to your speed being throttled.

A printer should also stay connected, even while you're not using it. it needs to clean the heads and can't do that if it's switched off at the wall. Without this, the heads could get clogged with ink and need replacing more often.

Luckily, printers don't tend to use much power any way, although ink can be pricey. The best way to cut costs is to make sure you own one of the best cheap printers to buy and run. Not in the market for a new printer? We can still help - we reveal the best cheap ink cartridges and where to buy them.

The best ways to save

In the long term, choosing energy efficient appliances is one of the best solutions to combat rising bills. 

Find out which energy efficient appliances will make big savings over time.

You'll find annual running costs in our reviews. This means you can compare models to see the difference over the course of a year. We change the kWh in line with price caps, so you know the figures will be up to date.

You can also use the filters on our reviews to choose a Which? Eco Buy product. The Eco Buy badge certifies that those products are more energy-efficient than most.

There are also plenty of budget-friendly tips to help reduce your energy bills, including lowering your boiler's flow temperature. You should also make the most of energy-saving or low-power modes on your devices. These savings will be small but can add up over time.

Need help managing your finances during the cost of living crisis? For personalised money-saving tips, try our free My Money Health Check tool.

How we get our energy figures 

Dr Steph Kipling, Science Team leader at Which?, explains how we get our energy figures when we test products.

'We measure energy consumption during lab tests, taking readings when the product is on and when it's on standby. This is combined with survey data of member usage to give an accurate, representative figure of how much products cost to run'.

'We use Ofgem’s price cap for the cost per unit of electricity and gas, and update our running costs when the price cap changes. You can estimate running costs yourself by multiplying the power rating of the product in Watts by the time in hours the product is in use, then divide by 1,000. 

'This gives the energy consumption in kilowatt hours (kWh), which can be multiplied by the cost per unit for energy (currently 34p for electricity). Scale this up to estimate the cost per week, month and year.

'However, this estimate might not be realistic for all products. While it's useful for simple products such as kettles, it's less accurate for complex systems such as ovens, washing machines and TVs. The equation assumes the product is always using full power, whereas ovens use more power while heating up, for example.  

 'Measuring actual energy consumption is more accurate – especially as we test products in the way people use them. For example, using the best picture settings on a TV, which can affect consumption'.

Join Which? Tech Support

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Information originally published in Which? Tech magazine December 2022. Additional reporting by Natalie Turner. Article updated September 2023 with latest energy prices.