alternative
background
bio
bioenergy
concept
conceptual
conservation
conserve
eco
ecofriendly
ecologic
ecological
ecology
efficiency
efficient
electric
electric cable
electricity
energy
environment
environmental
grass
green
idea
invention
light switch
nature
outdoors
power
receptacle
recycling
renewable
reprocessing
responsibility
reusable
saving
socket plug
sustainability
sustainable
switch
switchplug
technology