A novel hybrid power system with zero CO2 emission (ZE-SOLRGT) has been proposed and analyzed in this paper. It consists of a high temperature Brayton-like topping cycle and a high pressure-ratio Rankine-like bottoming cycle, integrated with methane-steam reforming, solar heat-assisted steam generation and CO2 capture and compression. Water is selected to be the working fluid. Solar heat input enhances the steam generation and power output, and reduces fossil fuel consumption. Besides CO2 capture with oxy-fuel combustion and cascade recuperation of turbine exhaust heat, the system is featured with indirect upgrading of low-mid temperature solar heat and cascade release of fossil fuel chemical exergy, which is described by the energy level concept. With nearly 100% CO2 capture, the system attains a net energy efficiency of 50.7% (including consideration of the energy needed for oxygen separation). The cost of generated electricity and the payback period of ZE-SOLRGT are found to be $0.056/kWh and 11.3 years, respectively. The system integration accomplishes the complementary utilization of fossil fuel and solar heat, and attains their high efficiency conversion into electricity.
