This paper presents an exergetic analysis of a combined heat and power (CHP) system, integrating a near-atmospheric solid oxide fuel cell (SOFC) with an allothermal biomass fluidised bed steam gasification process. The gasification heat requirement is supplied to the fluidised bed from the SOFC stack through high-temperature sodium heat pipes. The CHP system was modelled in AspenPlus (TM) software including sub-models for the gasification, SOFC, gas cleaning and heat pipes. For an average current density of 3000 A m(-2) the proposed system would consume 90 kg h(-1) biomass producing 170kW(e) net power with a system exergetic efficiency of 36%, out of which 34% are electrical. (C) 2007 Elsevier Ltd. All rights reserved.