Induced by promising hydrogen production of CeO2-based solar thermochemical cycle and evident temperature decreasing effect of methane reduction, a moderately high-temperature solar thermochemical ceria-methane cycle is investigated thermodynamically. In this paper, isothermal and non isothermal solar-to-fuel efficiencies (n(solar-to-fuel)) under different temperatures and reactant ratios are compared carefully. The calculated results indicate that the condition of CH4:CeO2=0.5 is favorable for oxygen release, fuel selectivity and methane conversion. The introduction of methane could increase the maximum yield of H-2, and more solar energy could be converted to chemical energy as the increase of n(H2O):n(CeO2). n(H2O):n(CeO2) = 0.5, T-red = 1400 K and T-oxi; = 750 K are suggested for the maximum non-isothermal n(solar-to-fuel) of 0.35, which is larger than the maximum isothermal n(solar-to-fuel) of 0.24. The result shows that non-isothermal solar thermochemical ceria-methane cycle is more feasible for fuel production. (C) 2019 Elsevier Ltd. All rights reserved.