In this work a thermoeconomic analysis of the joint production of electricity and water for a simulated 5 MWe Solar Thermal Power Plant (STPP) based on parabolic trough mirrors and Direct Steam Generation (DSG) is carried out. The location considered for this plant is Almeria, in southeast of Spain. Two different seawater technologies have been selected to be coupled with the STPP: Multi-Effect Distillation (MED) and Reverse Osmosis (RO). The Power Block (PB) has been designed to maximize the thermal efficiency, including regeneration and reheating. Four coupling arrangements have been investigated: the MED replacing the condenser of the PB, the MED being fed by one steam extraction of the PB, the RO directly using the electricity generated in the PB and the RO connected to the local grid. Results show that the best coupling option is with the RO unit being connected to the local grid, which produces the lower Levelized Water Cost (LWC). (C) 2016 Elsevier B.V. All rights reserved.