The ability of solid oxide fuel cells to convert not only H(2) but also CO and its utilization of a catalyst containing anode enabling the conversion of hydrocarbon fuels allows the use of wood gas. The hydrocarbons in the wood gas show the ability to be converted to H(2) and CO directly to a certain extent due to reforming reactions. Therefore the available amount of H(2) and CO at the anode is depending to what degree the hydrocarbons become reformed. In order to illustrate the impact of a varying hydrocarbon content and consequently of a varying available amount of H(2) and CO on the fuel utilization due to individual reforming rates, the performed tests with synthetic wood gas and varying naphthalene contents using a single-cell test rig are presented. The conversion of naphthalene impacts not only the open circuit voltage but also the cell voltage during operation. Therefore this paper focuses on the change of the cell voltage due to a changing available amount of H(2) and CO resulting from reforming of naphthalene and methane. The experimental results are compared with theoretical equilibrium calculations to illustrate the kinetic impact of the process parameters on the reforming mechanism. (C) 2010 Elsevier B.V. All rights reserved.