NOVELTY - Transporting renewable fuel comprises generating low density hydrogen fuel from biomass dissociation at a first location of a low elevation; self-transporting the low density hydrogen fuel in a pipeline to a second location at a higher elevation than the first location; generating a high density hydrogen carrier at the second location of higher elevation; and delivering the high density hydrogen carrier to a third location of a lower elevation than the second location while providing pressure or kinetic energy.    USE - The method or system is useful for transporting renewable fuel (claimed).    ADVANTAGE - The method or system can be used to avoid the high costs of compressing or cryogenically freezing biofuels, such as hydrogen and methane fuels. In addition, the costs associated with maintaining a pipeline for transporting gaseous and liquefied hydrogen fuel can be avoided. The method can be used to selectively respeciate a given renewable fuel for efficient storage and transport.    DETAILED DESCRIPTION - Transporting renewable fuel comprises generating low density hydrogen fuel from biomass dissociation at a first location of a low elevation; self-transporting the low density hydrogen fuel in a pipeline to a second location at a higher elevation than the first location, where the low density hydrogen fuel travels from the first location to the second location without adding energy or pressure; generating a high density hydrogen carrier at the second location of higher elevation by reacting the low density hydrogen fuel with at least one of a carbon donor, a nitrogen donor and an oxygen donor; and delivering the high density hydrogen carrier to a third location of a lower elevation than the second location while providing pressure or kinetic energy. An INDEPENDENT CLAIM is a pipeline system of transporting renewable fuel, comprising a biomass conversion plant at a first location of a low elevation to generate low density hydrogen fuel from biomass dissociation; a first pipeline connecting the biomass conversion plant to a second location of a higher elevation than the first location, where the low density hydrogen fuel travels within the pipeline from the first location to the second location without added energy of pressure; a thermochemical reactor connected to the second location of the higher elevation to generate a high density hydrogen carrier, where the thermochemical reactor reacts the low density hydrogen fuel with at least one of a carbon donor, a nitrogen donor and an oxygen donor; and a second pipeline connecting the thermochemical reactor to a third location of a lower elevation than the second location, where the high density hydrogen carrier is delivered to the third location with at least one of pressure or kinetic energy generated by the high density hydrogen carrier.