A Thermodynamic Model of Solar Thermal Energy Assisted Natural Gas Fired Combined Cycle (NGCC) Power Plant

A solar thermal energy assisted NGCC power plant was modeled to investigate the impact on plant efficiency, output and CO2 emission with solar thermal energy addition. In this particular model, with 23.7 MWth solar thermal energy input to the HRSG, the duct firing could be shut off, 2337.5 kg/h natural gas would be saved, and 6.2 t/hr CO2 emission would be eliminated. However, there would also be a 4.07 MWe loss in power from the combined cycle. Another solar input approach shows 14.35 MWe additional electricity would be generated with 35 MWth solar thermal energy addition. The thermodynamic analyses in this paper demonstrated the possibilities to utilize the solar thermal energy to reduce fuel consumption and CO2 emission, or to increase the NGCC power plant efficiency and output, while taking advantage of the already existing power plant infrastructure.