environmental
alternative
brainstorm
bulb
concept
conceptual
conservation
consumption
creative
earth
eco
ecofriendly
ecologic
ecological
ecology
electricity
energy
environment
future
genius
glass
global
green
idea
illuminate
innovation
invention
kyoto
lamp
light
lightbulb
natural
photosynthesis
planet
plant
power
process
renewable
resource
responsibility
reusable
reuse
sky
solar
solution
sunlight
sustainability
sustainable
symbol
technological
technology
warming
waste
wisdom