Optimization of a 600 MW supercritical solar-coal hybrid power plant and CO2 reduction analysis

In order to comprehensively evaluate the performance of the coupled system, a 600 MW coal fired power plant was investigated to study the performance of a solar-coal hybrid power plant. In conventional thermodynamic method, the production cost was neglected, however, a new method was developed to apply thermodynamics and thermoeconomics for comprehensively evaluating the performance of the hybrid system. The physical and thermoeconomic model of the hybrid system were established. The evaluation indexes of the hybrid system such as coal consumption, CO2 emission reduction, coal to cost ratio, energy efficiency, thermoeconomic generation cost and thermoeconomic coefficient were proposed, then the feasible coupling method of the solar-coal hybrid power plant was determined. The study results show that when the steam from the first extraction point is replaced by the steam from solar collector, the coal to cost ratio is the highest and it is 0.0499 g/(kW·h·¥). The payback period of this coupling method is the shortest. The coupling method with the lowest thermoeconomic generation cost, coal consumption and the highest CO2 reduction is to replace the steam from the second extraction point with the steam from solar collector. The thermoeconomic generation cost, coal consumption reduction and CO2 emission reduction of the coupling method are 0.3445 ¥/(kW·h), 13.49 g/(kW·h) and 17.80 t/h respectively. Therefore, the feasible coupling method of the solar-coal hybrid power plant is to replace the steam from the second extraction point with the steam from solar collector. © 2015, China Coal Society. All right reserved.