abstract
alternative
background
blue
bright
concept
connect
connection
current
day
design
earth
eco
ecological
ecology
electric
electrical
electricity
energy
green
heat
icon
idea
industry
lamp
light
line
plug
power
ray
save
savings
shiny
sign
sky
socket
solar
summer
sun
sunbeam
sunlight
sunny
sunset
sunshine
supply
symbol
technology
white
wire