The amount of energy used by consumer electronics and domestic appliances in UK homes will double by 2010, said a report from the Energy Saving Trust.
The trust blames the rising number of electronic items in homes
It said the rise in popularity of computers and games consoles has created a huge extra need for power.
The large volume of sales has wiped out the effect of energy efficiency measures in new devices, it found.
By 2010 digital TV set-top boxes alone will cost up to £780m a year to run, said the trust.
A typical 1970s home contained just 17 energy-using products such as washing machines.
Three decades later juicers and electric toothbrushes have helped to double the number of electricity-hungry items in the average household.
Central heating systems are still the biggest culprits when it comes to guzzling electricity.
However, the trust is concerned that consumer devices will fuel a major rise in domestic energy demand by the end of this decade.
The Energy Savings Trust is a non-profit organisation funded by both the government and the private sector.