California will soon become the first US State to introduce energy efficiency standards for computers.

It is hoped energy consumption will be reduced by a third, cutting carbon emissions and saving consumers around $373 million (£300.57m) by 2027.

Computers in California currently account for up to 3% of residential and 7% of commercial energy usage, reaching almost 5,610GWh of electricity each year.

Desktops are four times more power-intensive than laptops, giving them the nickname “energy vampires”. Research from the University of California shows the average desktop is turned on as much as 77% of the time but spends 61% of this time not being used.

The new rules will make desktops reduce idle power use by 30% by 2019 and 50% by 2021.

Most desktops and monitors will be affected but around three quarters of laptops won’t have to change anything as they are already judged to be efficient enough.

The first rules will come into action on the first day of 2018 – prices are likely to be pushed upwards as a result but this should be significantly outweighed by the cost savings of energy.

Andrew McAllister, a Commission Member and advocate of the new regulations, said: “Such efficiency improvements are good for consumers, good for the electric system, good for the environment and frankly good for the green credentials of the manufacturers.”