Economy analysis of the solar supported coal-fired power generation (SSCPG) system

Integrating the solar utilization system with the coal-fired power plant into the solar supported coal-fired power generation (SSCPG) system shows an effective way for the large-scale utilization of solar energy and energy conservation in coal-fired power units currently in China. Two SSCPG systems integrating solar utilization system with C50-8.83/0.294 heat and electricity cogeneration unit are taken as examples to analyze its economy. Firstly, thermal performances of these two SSCPG systems are given by using solar heat electricity efficiency, solar heat input fraction, solar electricity generation fraction and so on as thermal economy evaluating indicators. The influence of location, operation mode on their thermal performance is also discussed. Then unit electricity generation cost of the SSCPG system is calculated, in which investment cost is involved. The results show that, on the condition assumed in this paper, the unit electricity generation cost of the SSCPG system of reducing 1# bled steam individually is 0.0386$/kW.h, a little higher than that of the coal-fired only system, 0.0356$/kW.h. But the unit electricity generation cost of solar part of it is 0.082$/kW.h, lower than that of solar only electricity generation system, 0.14$/kW.h. Finally, sensitivity analysis on the unit electricity generation cost is conducted. And the conclusion is that when collector price drops to 48$/m(2) and coal price increases to 368$/t meanwhile, the unit electricity generation cost of the SSCPG system of reducing 1# bled steam individually will be equal to that of the coal-fired only system as the discount rate is 12%.