Abstract

Concentrated solar power (CSP) converts sunlight into heat for mechanical or electrical energy generation, offering a dispatchable alternative to variable renewables and often integrating thermal energy storage (TES) to extend power delivery beyond daylight hours. The Kalina cycle, employing an ammonia–water working fluid, enables variable-temperature heat exchange and reduces exergy losses compared with conventional Rankine-based systems; however, its application in CSP remains limited. This study evaluates the feasibility of a 10 MW high-temperature Kalina cycle (HT-KC) coupled to a parabolic trough collector (PTC) field and molten-salt TES under real-world Mexican solar conditions. Through exergy-efficiency optimization via the Variable Metric Method and solar-field sizing at a solar multiple of 1.5 for the 21 June design point, the HTKC achieves a first-law efficiency of 32.51% and an exergy efficiency of 66.4% under design-day conditions, attains an annual solar fraction of 41.87%, and maintains a capacity factor of 44.10%. Compared with a 10 MW direct-steam-generation Rankine benchmark—which delivers higher peak efficiencies (26% energy, 35% exergy) but requires larger fields and lacks cost-effective storage—the HT-KC demonstrates superior dispatchability and operational flexibility. These results provide a rigorous framework for designing reliable renewable power systems in high-irradiance regions and support strategic planning for grid-stable decarbonization.