Abstract: A solar tower power aided coal-fired power generation system for a typical 350 MW subcritical coal-fired power plant in china was proposed.The solar tower power system,named solar boiler,extracted about 5% feed water from the high pressure heater and heated it to the same parameters as that of the coal-fired boiler.The steam generated from the solar boiler joins the main steam from the coal-fired boiler at the inlet of turbine.The simulation model of solar tower power aided coal-fired power generation system was developed by modular modeling method.According to the solar data of the Spring Equinox,the system behavior since the cold start of the solar boiler in the morning of the first day to the shutdown at sunset of the day was simulated.The hot start process of the system was also simulated.The simulation results show that the startup of the solar boiler causes fluctuation of the coal-fired power plant,but the fluctuation can be eliminate by the regulation of the control system.Since the parameter of the solar boiler should match the coal-fired boiler,the steam flowrate of the solar boiler changes with the solar power and reach maximum at midday.The time used for hot start is less than cold start,and the continuous running of the system will reduce the coal consumption of the power plant significantly.Every day’s startup and shutdown of the solar boiler caused by the intermittent solar power will enhance the fatigue life consumption of the solar boiler.