Abstract: A solid fuel containing a recycled residue from anaerobic fermentation or anaerobic digestion of an organic material. The solid fuel can also contain a volatile solid fossil fuel. The residue is preferably derived from an anaerobic digestion process of municipal solid waste, raw sewage sludge, biomass feedstock, industrial waste, agricultural waste or mixtures thereof. The volatile solid fossil fuel preferably contains a coal constituent of lignite, anthracite coal, meta-anthracite coal, bituminous coal and/or sub-bituminous coal. Regardless of whether the solid fuel contains only recycled residue or recycled residue bound with a volatile solid fossil fuel, the solid fuel can be formed into pellets or energy cubes.