Desktop computers left on overnight could add almost £230 a year to energy bills, analysis finds
Households are being urged to check their computer usage habits as new analysis suggests leaving a desktop computer running could add significantly to already-rising energy costs. The warning comes as E.ON Next forecasts that the October energy price cap could reach £1,725 for a typical household, an increase of £62 compared with the July 2026 cap.
According to analysis from mini PC manufacturer GEEKOM, a typical 150W desktop computer used for eight hours a day costs an estimated £114.36 a year in electricity. However, leaving the same computer running around the clock increases that estimated cost to £343.09 a year—a difference of £228.73 every year, or more than £1,140 over five years.
The hidden cost of idle computers
The findings come from GEEKOM's PC Running Cost Calculator, which allows households to estimate how much their computer costs to run based on power consumption, daily usage, and electricity tariff. The figures are calculated against a typical electricity tariff and standard usage patterns.
Over a five-year period, a 150W desktop used for eight hours every day could cost around £572 to run, while the same machine left running continuously could cost more than £1,715. The analysis also highlights the energy efficiency of different devices: a 50W laptop used for eight hours a day costs approximately £38.12 a year to run, while a 25W mini PC costs approximately £19.06 a year. The potential difference in annual running cost between a 150W desktop and a 25W mini PC, both used for eight hours a day, is around £95 per year.
Expert advice: small changes, significant savings
Max Tang, Chief Marketing Officer at GEEKOM, said that while energy bills are often associated with heating and large appliances, the technology on desks is 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," he said.
Tang added 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."
Practical tips to reduce computer electricity costs
GEEKOM's analysis includes seven tips for cutting computer electricity costs. These include switching the computer off when not in use, checking sleep settings, not just switching off the monitor, using power-saving settings, reducing screen brightness, considering energy efficiency when replacing hardware, and checking peripherals. The company notes that switching off the monitor does not necessarily mean the computer itself has stopped consuming electricity.