The carbon fuel cell, a novel electrochemical conversion scheme for the production of efficient electric power from solid carbonaceous fuels, is investigated. A model of the carbon fuel cell is developed, validated, and exercised to explore the interactions between cell geometry, power output, and overall efficiency. The model is built on the Boudouard reaction mechanism and includes experimentally measured kinetic parameters of the electrode and carbon bed reactions. Results indicate that the modeled cell geometry can operate in an optimal regime offering efficiencies near 60% and cell power densities of 100 mW cm(-2). The model further reveals a fundamental tradeoff between efficiency and power output inherent in a carbon fuel cell, suggesting that high cell efficiencies can be obtained at half of peak power output. (c) 2012 Elsevier B.V. All rights reserved.