Computers, copiers and printers sold the European Union and the U.S. will have to become more energy-efficient from next month in order to gain Energy Star approval, following an agreement signed Wednesday by the European Commission and the U.S. Environmental Protection Agency.

The energy savings from the new specifications for home and office equipment are expected to total 22TWh (terawatt hour) over the four- to six-year lifetime of the products -- roughly equivalent to Ireland's total annual energy consumption, the Commission said in a statement.

The list of machines currently approved under the E.U.-U.S. Energy Star scheme includes 70 desktop PC brands, 43 laptops and tablet PCs, 18 copiers, 32 printers, 19 scanners and 14 fax machines.

"The new criteria are an important contribution to reach the E.U.'s energy efficiency targets," said the European energy commissioner Andris Pielbags.

Computers are expected to account for most of the savings: 18 TWh out of the 22 TWh target, the Commission said.The E.U.-U.S. Energy Star scheme will in future be extended to cover other product categories including servers, data storage equipment and video games consoles.