The growing popularity of hi-tech devices, such as flat-screen TVs and digital radios, threaten to undermine efforts to save energy, a report says.
UK consumers spend £12bn a year on electronics, much of which is less efficient than older technology, a study by the Energy Saving Trust found.
By 2020, the gadgets will account for about 45% of electricity used in UK households, the organisation projected.
It said flat-screen TVs and digital radios were among the worst offenders.
Paula Owen, author of the report called The Ampere Strikes Back, said household appliances currently consumed about a third of an average home"s electricity.
But she warned this was likely to increase as a result of people buying more energy intensive devices.