background
bright
bulb
compact
concept
conservation
eco
ecological
ecology
economical
economy
efficiency
efficient
electric
electrical
electricity
energy
environment
environmental
equipment
fluorescent
glass
glowing
grass
green
idea
illuminated
innovation
invention
kilowatt
lamp
light
modern
nature
object
power
save
saver
savings
single
spiral
symbol
technology
tube
utility
watt
white