This paper discusses the formulation of an optimal control strategy taking into account economic objectives in the fresh water production process through a solar seawater desalination plant. It contributes both a linearised model of the solar-field dynamics and a simplified model of the produced distillate as a function of the outlet solar field water temperature. Then such linear models are used to design an economic receding horizon optimal controller. In particular, it comprises incomes related to the production of fresh water and the costs dealing with the electricity. Several simulations validate the proposed models and show the performance of the proposed economic optimal control strategy. In both cases, actual disturbances from physical experiments have been included in the simulations. Notice that the AQUASOL facility available at the Plataforma Solar de Almeria (Spain) has been considered in this work as testbed. (C) 2014 Elsevier Ltd. All rights reserved.