A thermoeconomic analysis of a solar polygeneration plant for the joint production of electricity, fresh water, cooling, and process heat is carried out, in order to analyze in depth the process of exergy cost formation and comparing with standalone systems. The solar polygeneration plant consists of a concentrated solar power as prime mover, and a multi-effect desalination, a refrigeration absorption, and a process heat plants. Results show that the main components that contribute to the costs formation are: solar collectors, evaporator, re-heater, economizer, turbine, and super-heater. Also, a solar polygeneration plant is more cost effective than stand-alone systems, which produces the lower unit exergy cost of electricity, water, cooling and heat.