Combined cooling for CSP plants: Modeling, experimental validation and optimization analysis

The global development of Concentrated Solar Thermal Power (CSP) projects demands new technologies that enhance the thermal efficiency of power cycles without increasing costs or environmental impact. Among the subsystems of the power cycle, the cooling circuit plays a critical role, as it must minimize water consumption while maintaining high efficiency; a challenge that is particularly relevant in arid regions where many CSP plants are installed. This paper presents a model for a cooling system that combines Dry Cooling (DC) and Wet Cooling Tower (WCT) technologies, enabling multiple operating configurations (parallel, series, parallel–series, only-WCT, and only-DC). The model was validated using experimental data from a 200 kW th pilot plant, achieving a Mean Absolute Error (MAE) below 0.97 ° C for system temperatures and 19.4 l/h for water consumption. An optimization analysis was also performed, demonstrating the potential of the proposed technology to provide adaptive cooling for CSP plants under varying seasonal and operating conditions. For the pilot plant during summer, optimally combining DC and WCT in a parallel series configuration enabled a nearly continuous variation in specific electricity consumption, ranging from 0.06 kW e / kW th in only-DC operation to values up to 90 % lower in only-WCT mode, at a water usage cost of 1.48 l/kWh th . • Physical model to predict the performance of combined cooling systems. • Validated the model experimentally, achieving a MAE of 0.41 ° C for the condensate temperature. • Performed optimal operation analysis across multiple case studies. • Demonstrated the potential of combined cooling for CSP plants using optimization tools.