I don’t completely agree with the coal being a bad guy thing . Coal is wood that’s been sitting longer . Burn anything and you release carbon dioxide . Coals bad rep comes from the big coal fired electrical generators . People brag about how green their electric cars , lawn mowers , etc . are but a coal fired generator recharges them . What concerns me more is the water that solar panels use to cool themselves . Anyway , no real answers to any of it but coal heat in your home is the cheapest way to go and isn’t dependent on electricity .