A thermoelectric reformer unit-for dissociating fossil-based hydrocarbons, renewable hydrocarbons or hydrogen-containing inorganic compounds to produce hydrogen in a reactor using thermoelectric technology with thermoelectric materials to achieve very high conversion efficiencies. Thermoelectric reforming occurs in a reactor core containing a number of energy sources. These energy sources generate extremely high temperature heat that reacts with the fuels in its local surrounding areas. Since the heat is locally generated, it will not penetrate far within the reactor core that is surrounded by walls that act as a casing for the reformer. Synthetic gas produced in the reformer can be fed into internal combustion engines certain, types of fuel cells, or other energy conversion equipment without or with only limited levels of purification. Ancillary components are needed to produce high-purity hydrogen fuel for other types of fuel cells.