Thermo-economic Optimization of Solar–Coal Hybrid Systems

In this paper, an economic optimization of the solar multiple for the solar-coal hybrid systems was presented. The solar heat at approximately 300 °C was used to preheat the feed water before entering the boiler in the typical coal-fired power plants. Three different unit scale coal-fired power plants have been considered, with the different parameters in the power block and different solar field sizes. Thermal performance for each solar power plant has been featured, both at design and off-design conditions under the climatic conditions of Shizuishan City. The economic assessments were then performed. The costs and payback period of each configuration with different steam extraction replaced were compared, using the well-established cost-estimating methodology. The levelized cost of energy (LCOE) for each case is calculated, yielding a minimum LCOE value for a certain solar multiple value within the range considered.