燃やす
alternative
background
bio
biofuel
biology
biomass
boiler
boiler room
domestic
eco
ecological
ecology
economy
energy
environment
environmentally
fire
fuel
granule
heap
heat
heating
industry
mass
natural
nature
pellet
pellets
pine
power
recycling
renewable
sawdust
solid
texture
timber
waste
wood
woodchip
wooden