With the shortage of fossil fuels and its negative effects on the environment, solar energy as one type of renewable energy has attracted increasing attention both socially and politically. There are two approached to use solar energy for generating electricity, i.e., using solar energy to directly to make work or integrating solar energy into fossil-fueled plant. The solar-aided coal-fired power generation (SACPG) mechanism is proven an effective way to use solar energy efficiently. In this paper, SACPG system and solar-alone parabolic trough CSP plant are modelled respectively. A comparison discussion related to TES system between SACPG system and solar-alone CSP plant is presented. The aim is to find what role of TES system will play in these two different systems.
Through analysis, the role TES system plays varies in solar-alone power generation system and SACPG system. For solar-alone power generation system, the main function for TES system lies in storing surplus solar heat. Besides, there exists an optimum loop number with highest annual SEE with a specific TES hour. However, TES system for SACPG system not only stores the surplus solar heat, but also adjusts working condition. With the help of TES system, the working condition could be set as the high-pressure extraction steam could be totally replaced by solar heat. By doing so, annual solar power generation and annual SEE could be improved compared with that without TES system.