Technical and economical optimization for a typical solar hybrid coal-fired power plant in China

Solar hybrid coal-fired power plant can use solar heat with temperature lower than 300 °C to generate power efficiently by replacing the bled-off steam from a steam turbine to heat the feed water. In this paper, a model of the solar field and power block has been developed to investigate the thermodynamic and economic performances of a solar hybrid coal-fired power plant under a variety of operating conditions and structure layouts. The effects of the key operating parameters on the performances of the solar hybrid coal-fired power plant are numerically investigated. A technical and economical optimization of the solar multiple has been presented. Furthermore, the annual solar-to-electric efficiency, annual solar power output and levelized cost of electricity of the solar hybrid coal-fired power plant are also analyzed. It is found that the efficiencies in the region of 13-20% can be achieved, and this for levelized cost of electricity in the region of 0.7-1.1 ¥/kW he, depending on the solar multiple and substituting method.