alternative
background
bio
biomass
block
brick
briquet
briquette
briquettes
briquetting
brown
burnable
chip
coal
combustible
compressed
cut
dry
ecology
energy
fire
firewood
fuel
group
heap
heat
industry
isolated
log
lumber
material
natural
pile
power
pressed
resource
sawdust
stack
temperature
texture
timber
tree
waste
white
wood
wooden