'power-efficient' originates from English, specifically the combination of the words 'power' and 'efficient', where 'power' referred to 'energy or force' and 'efficient' derived from Latin roots meaning 'producing an effect without waste'.

'power' comes into English via Old French (e.g. 'poeir') from Latin roots related to 'posse/posse' (to be able), while 'efficient' comes from Latin 'efficere' (ex- + facere 'to do, make'); the compound 'power-efficient' is a modern English formation (20th century onward), modeled on earlier compounds such as 'energy-efficient'.

Initially it simply combined the meanings of 'power' and 'efficient'; over time it has come to be used as a technical descriptor specifically for devices, systems, or designs that minimize electrical power use while maintaining performance.