Annual economic performance of a solar-aided 600 MW coal-fired power generation system under different tracking modes, aperture areas, and storage capacities

The solar-aided coal-fired power generation (SACPG) system is proven to be an effective way to use solar energy. In this work, a 600 MW SACPG system using solar parabolic trough technology is simulated based on hourly meteorological data. Solar field is used to preheat feedwater to replace high-pressure extraction steam of the original coal-fired unit. Based on annual and off-design performance, the main parameters of the SACPG system, such as thermal energy storage (TES) hours, solar multiple (SM) and ratio of row spacing to aperture width (S/W ratio) are optimized from the thermodynamic and economic viewpoints. Besides, a sensitive economic analysis is performed when the cost of a specific component changes. The thermodynamic and sensitive economic analysis reveals the S/W ratio should be determined depending on land cost and tracking mode to balance between annual solar-to-electricity efficiency (SEE) and lower levelized cost of electricity (LCOE). Besides, although a TES system could annual SEE of SACPG system, its optimized capacity should be determined by the cost of the solar field and the TES system. Therefore, a balance point is proposed in the end to determine on what condition it is economical to set a TES system. (C) 2016 Elsevier Ltd. All rights reserved.