The physical model of the coal-fired power system and the solar hybrid coal-fired power system is established. Starting from the energy balance equation and exergy balance equation

this paper derived the formula of the solar-to-electricity efficiency of the solar hybrid coal-fired power system. Besides

the thermodynamic properties of the solar hybrid coal-fired power system are analyzed. The influence of the receiver temperature

concentration ratio and solar irradiation intensity on the solar-to-electricity efficiency is studied. As a result

higher solar-to-electricity efficiency could be got when higher state extracted steam is replaced by solar heat. When the same stage extracted steam is replaced by solar heat

the higher solar-to-electricity efficiency is achieved for lower receiver temperature. For a given receiver temperature and a given solar irradiation intensity

the solar-to-electricity efficiency increases with the concentration ratio. For a given receiver temperature and a given concentration ratio

the solar-to-electricity efficiency increases with the solar irradiation intensity. The research in this paper will provide a theoretical reference for design and optimization of the solar hybrid coal-fired power systems.