The multiobjective optimization of a corn-based bioethanol plant coupled with a solar-assisted steam generation system with heat storage is described. Our approach relies on the combined use of process simulation, rigorous optimization tools, and economic and energetic plant analysis. The design task is posed as a bicriteria nonlinear programming problem that considers the simultaneous optimization of the plant profitability and the energy consumption. The capabilities of the proposed methodology are illustrated through a 120,000,000 kg/year corn-based bioethanol plant considering weather data of Tarragona (Spain). (c) 2013 American Institute of Chemical Engineers AIChE J 60: 500-506, 2014