In this paper we address the integration of a polygeneration system based on biomass with a concentrated solar power facility for the constant production of electricity over a year long. The process is modelled as a superstructure embedding two different gasification technologies, direct and indirect, and two reforming modes, partial oxidation or steam reforming followed by gas cleaning and three alternatives for the syngas use, water gas shift reactor (WGSR) to produce hydrogen, a furnace for thermal energy production and an open Brayton cycle. We couple this system with a concentrated solar plant that uses tower technology, molten salts and a regenerative Rankine cycle. The problem is formulated as a multi-period mixedinteger non linear programming problem (MINLP). The optimal integration involves the use of indirect gasification, steam reforming and a Brayton cycle to produce 340 MW of electricity at 0.073 /kWh and 97 kt/yr of hydrogen as a credit. (C) 2013 Elsevier Ltd. All rights reserved.