b _ o g _ s p _ w _ r
biogas power
s _ l a _ e _ e r _ y
solar energy
p _ o d _ c _
produce
w _ n d p _ w _ r
wind power
h _ r _ f _ l
harmful
a _ v a _ t a _ e
advantage
g _ e e _ h o _ s _ g _ s e s
greenhouse gases
s _ s t _ i n _ b _ e
sustainable
F _ s s _ l f _ e _
Fossil fuel
a _ a i _ a _ l _
available
c _ a _
coal
r _ n o _ t
run out
a _ u n _ a _ t
abundant
a _ t e _ n a _ i _ e
alternative
p _ l _ u _ e
pollute
f _ n d _ m e _ t _ l
fundamental