The paper presents the calculation results for three variants of CHP plant fuelled by sawmill biomass. The plant shall produce electricity and heat for a drying chamber. An analysis of the system efficiency for four different working fluids was conducted: octamethyltrisiloxane, methylcyclohexane, methanol and water. The highest electric power was obtained for the system with internal regeneration and methylcyclohexane applied as the "dry" working fluid, the highest temperature to supply the drying chamber was obtained for the system with external regeneration and octamethyltrisiloxane applied as the working fluid. The results of the analysis indicate that, by proper choice of the working fluid and of the regeneration variant (internal or external), it is possible to "adjust" the work of the system to the needs and expectations of the plant investor (user). (C) 2014 Elsevier Ltd. All rights reserved.