energy efficient
adjective
NATURAL RESOURCES, ENVIRONMENT ukus(also energy-efficient)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