Integrating solar energy into a conventional fossil-fuel fired power plant through solar-aided coal-fired
power generation (SACPG) mechanism has been proven to be an efficient way to use solar energy for
power generation purposes. However, due to the rather intermittency of solar radiation, SACPG systems
always work under off-design conditions. In this paper, hourly based annual performances of a SACPG
system was simulated and analyzed with various solar field sizes and thermal energy storage (TES) capacity
under different (plant) load conditions in a 330 MW power plant case study. The results indicate that,
TES system could stabilize the solar thermal output and improve the stability of the SACPG system at different
loads. And it could also improve solar contribution in the power generation and annual peak solarto-
electricity efficiency. Through case study, the minimum levelized energy of costs and corresponding
aperture area in this case are $0.0629/kW h, 1.413 _ 105 m2 for 100% load, $0.0654/kW h,
9.42 _ 104 m2 for 75% load, and $0.0730/kW h and 5.89 _ 104 m2 for 50% load, respectively. And the
corresponding optimized TES hour with different loads is found to be 0.5 h. The values are relatively
lower than the reference trough plant.