This study presents a thermoeconomic analysis of a CSP+MED plant to evaluate the impact of time-varying conditions (ambient temperature, part-load operation, solar irradiation) on the unit electricity and water thermoeconomic costs. The analysis considered a 100 MW CSP plant coupled to a 45,000 m3/day IVIED plant, in Crucero, Chile, located at 1200 m above the sea level and 80km from the coast. A parametric analysis varying the part-load operation and the ambient temperature was carried out, and an evaluation of the CSP+MED plant for eight summer and winter days was performed. Results allow determining the conditions impact and the cost allocation of the main systems of the plant in the products cost. It was obtained that the DNI has the main impact on both costs, followed by the part-load operation that has a significant impact, and the ambient temperature which has a moderate effect in the water cost. Moreover, it was determined that the CSP cost allocates 83% of the unit electricity cost and 60% of the unit water cost.