NOVELTY - The invention presents a method of gas-generation of hydrogen aboard transportation vehicles equipped with electric power plants. The group of inventions is dealt with a method of gas-generation of hydrogen, which may be used in the transportation vehicles supplied electrical power plants. The method of gas-generation of hydrogen by the first alternative is realized using reaction of the fuel (carbon) with water steam. At that a part of the energy produced by fuel elements is directed on realization of the process of generation of hydrogen. For production of the water steam they use the water produced by fuel elements, which is transformed in the steam phase due to a regenerative heat exchange between the products of the gas-generation - the blue gas and water. The mixture of hydrogen, carbon dioxide, carbon oxide and water steam, which is formed in process of reaction of the fuel with the water steam is subjected to two-four recirculations. The method by the second alternative provides for a process of pyrolysis of polymeric fuel (for example polyethylene) and a double conversion. The mixture of hydrogen, carbon dioxide, carbon oxide and water steam, which is formed during reaction of polymeric fuel with water steam, is subjected to two-four recirculations. The complex of chemical reactions is realized either in one reaction zone with simultaneous prevention of its coking or, as a minimum, in two reaction zones, or, as a minimum in two independent reaction zones, in one of which the pyrolysis of initial polymeric fuel takes place and in another - a two-stage reaction of conversion of pyrolysis products is going on. The part of the electric power produced by fuel elements is used to support reactions of pyrolysis and conversion. Supply of the reaction zone by water steam is provided in the process of the water regeneration produced in the fuel elements. At that the water steam is formed due to the regenerative heat exchange of this water with the reaction products removed from the zone. The technical result is in emission-free operation of the gas generator of hydrogen in a combination with a simplicity of the process of supply of the transportation vehicle electric power plant with the solid fuel with simultaneous preservation of the existing infrastructure of the fuel filling, in decrease of the mass of the plant and in increase of reliability of its operation.    USE - Usage of generated hydrogen aboard transportation vehicles equipped with electric power installations.    ADVANTAGE - Emission-free operation of the gas generator of hydrogen, simplicity of supply of the transportation vehicle electric power plant with the solid fuel, preservation of the existing infrastructure of the fuel filling, decreased the mass of the plant, increased reliability of its operation. 3 cl, 2 dwg, 2 ex