Exergetic and Exergoeconomic Analyses of a Parabolic Trough Solar Power Generation System

As concentrating solar power technologies moves to maturity progressively, large-scale solar thermal power plants have gained increasing attention. The exergetic and exergoeconomic analyses allow indicating energy degradation of the component quantitatively and establishing the monetary value to all material and energy flows. Therefore, they have strong theoretical implications to the system optimization. A thermodynamic simulation model of a 50 MW parabolic trough solar power generation system and the related exergetic and exergoeconomic analyses were presented in this paper. The results of exergetic analysis showed that the component of the lowest exergy efficiency was solar field, and the efficiency only had approximate 22%. Moreover, the exergy efficiencies of thermal energy storage and power block were about 81% and 58% respectively. According to the exergoeconomic analysis, the exergoeconomic cost of electricity and output thermal energy of solar field and thermal energy storage varied respectively in the ranges of 0.1277–0.1322 $/kWh, 0.0427–0.0503 $/kWh, and 0.0977–0.1074 $/kWh when thermal energy storage capacity ranged from 4 hours to 12 hours.