Households are being warned that leaving a desktop computer running around the clock could add almost £230 a year to their electricity costs, as bills are predicted to rise in October. E.ON Next has forecast that the October energy price cap could reach £1,725 for a typical household, an increase of £62 compared with the July 2026 cap.
Analysis from mini PC manufacturer GEEKOM found that a typical 150W desktop computer used for eight hours a day costs an estimated £114.36 a year in electricity. But leaving the same computer running continuously increases that estimated cost to £343.09 a year.
That is a difference of £228.73 every year, or more than £1,140 over five years, compared with switching the machine off outside an eight-hour working day.
Why computers keep consuming power
The findings come from GEEKOM's PC Running Cost Calculator, which allows households to estimate how much their computer costs to run based on its power consumption, daily usage and electricity tariff. With working from home, gaming and everyday browsing meaning computers are now used for hours at a time in many households, experts say it's easy to forget how long devices remain powered after they're actually needed. Switching off the monitor does not necessarily mean the computer itself has stopped consuming electricity.
Max Tang, CMO of GEEKOM, said: “Energy bills are likely to be front of mind again as we head towards October and the colder months, but most people will immediately think about heating and large household appliances. The technology sitting on our desks is much easier to overlook. If you finish work at five or six o'clock but your desktop stays running all evening and overnight, you're using electricity for hours when you're getting no benefit from it.”
“Our calculations show that the difference between using a typical desktop for eight hours a day and leaving it running around the clock could be almost £230 a year. Before autumn really sets in, it's worth taking five minutes to check your computer's power settings and making sure it's actually going to sleep or being switched off when you finish using it.”
Hardware choice makes a difference
Someone using a 150W desktop for eight hours every day could spend around £572 over five years powering the computer alone. For a machine left running continuously, that rises to more than £1,715.
Hardware choice can also make a substantial difference. Based on the typical power assumptions used in the calculator, a 50W laptop costs around £38.12 a year to use for eight hours a day, while a 25W mini PC costs approximately £19.06. That compares with £114.36 for the 150W desktop modelled, representing a potential difference of around £95 a year between the desktop and mini PC scenarios.
Seven ways to cut your computer's electricity costs before October
GEEKOM's experts recommend:
- Switch your computer off when you've finished for the day – leaving a desktop running overnight can mean hours of unnecessary electricity consumption. If you don't need remote access or background processes running, shut it down.
- Check your sleep settings – set your computer to automatically enter sleep mode after a short period of inactivity. This can dramatically reduce consumption when you forget to switch it off manually.
- Don't just switch off the monitor – a blank or switched-off screen doesn't necessarily mean the computer itself has stopped consuming significant electricity. Check whether the PC has actually entered sleep mode or shut down.
- Use power-saving settings – Windows and macOS both include built-in energy-saving modes that can reduce processor activity and other unnecessary power consumption during everyday tasks.
- Reduce your screen brightness – monitors contribute to the overall electricity consumption of a home-office setup. Keeping brightness at a comfortable rather than maximum level can help reduce unnecessary energy use.
- Consider energy efficiency when replacing your computer – different types of computers can have very different power requirements. If you mainly use your machine for browsing, emails, streaming and office tasks, consider energy consumption alongside performance when it's eventually time to replace it.
- Check what's still running on your desk – additional monitors, printers, speakers and other peripherals can all contribute to a home office's electricity consumption when they're left powered unnecessarily.
The exact cost of running a computer will vary depending on the device, how long it's used each day and the household's electricity tariff. Brits can check how much their own setup could be costing them using GEEKOM's free PC Running Cost Calculator, which allows users to compare devices, adjust daily usage and enter their own electricity rate.
