Thermodynamic modeling of the solid oxide fuel cell fed by the biomass gasification products was performed. The gasification using the heat of the hydrothermal reaction of the aluminum oxidation is considered as a potential expansion of the aluminum-hydrogen technology. Gasification products after the separation of the condensed phase, consisting of the ash and the aluminum oxide, become a synthesis gas with high heating power. In the fuel cell modeling only one electrochemical reaction was considered – the hydrogen oxidation. The consumption of methane and carbon monoxide was supposed to follow an equilibrium state of steam reforming and shift reactions. Power plant efficiency was found to be greater than 65% for the current density values up to 1 A/cm², when an experimentally proven value is used for the polarization resistance of membrane-electrode assembly (MEA). The relation of aluminum and biomass flow rates diminishes under the increasing pressure, and under the pressure 200 atm the aluminum to biomass ratio becomes less than 0.14. Thus the aluminum looks like a mere ancillary fuel.