energy efficient UK US adjective (also energy-efficient) NATURAL RESOURCES, ENVIRONMENT
► used to describe things that use only as much energy as is needed without wasting any: energy-efficient lighting/building/appliance »
The company has fitted energy-efficient lighting throughout the building.
»energy-efficient technology/system
»We need to become more energy efficient so that we don't generate power just to waste it.
energy efficiency noun [U]
► »
a drive to promote energy efficiency in the workplace
Financial and business terms. 2012.