A novel hybrid plant for a mixture of methane and hydrogen (enriched methane) production from a steam reforming reactor whose heat duty is supplied by a molten salt stream heated up by a concentrating solar power (CSP) plant developed by ENEA is here presented. By this way, a hydrogen stream, mixed with natural gas, is produced from solar energy by a consolidated production method as the steam reforming process and by a pre-commercial technology as molten salts parabolic mirrors solar plant. After the hydrogen production plant, the residual heat stored in molten salt stream is used to produce electricity and the plant is co-generative (hydrogen + electricity). The heat-exchanger-shaped reactor is dimensioned by a design tool developed in MatLab environment. A reactor 3.5 m long and with a diameter of 2 '' is the most efficient in terms of methane conversion (14.8%) and catalyst efficiency (4.7 Nm(3)/h of hydrogen produced per kg(cat)). Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.