The first objective of this study was to compare the mass and energy balances for a conventional air blown fluidized bed gasifier and a ballasted fluidized bed gasifier developed at Iowa State University. The ballasted gasifier is an indirectly heated gasifier that uses a single reactor for both combustion and pyrolysis. Heat accumulated in high temperature phase change material during the combustion phase is released during the pyrolysis phase to generate producer gas. Gas composition, tar and char contents, cold gas efficiency, carbon conversion, and hydrogen yield per unit biomass input were determined as part of these evaluations. Another objective of this study was to compare the cost of producing hydrogen by two types of biomass gasifiers: a conventional air blown fluidized bed gasifier and a thermally ballasted fluidized bed gasifier developed at Iowa State University. Experimental data has been scaled up to calculate the cost and feasibility associated with 50 Mg of hydrogen per day production plants. A detailed analysis based on a state by state model is used to demonstrate the effect of biomass cost on hydrogen production cost. This model also predicts the potential number of 50 Mg of H2/day plants that might be built in each state based on potential switchgrass supply.