Galvanized Metal?

[chemistguy]

Coal is not renewable while charcoal is. Trees take CO2 out of the atmosphere. Burning coal releases mercury and other heavy metals (toxic) and sulfur dioxide (leads to formation of smog and acid rain). Mining coal destroys entire mountains and the runoff from mines poisons waterways and causes cancer hotspots.

 

[Ocelot85]

You could always make your own charcoal if you've rejected the use of coal or gas, it'd be cheaper than buying it.