Benchmarking carbon emissions of coal power against natural gas power via renewable energy integration

This study develops an integrated power system combining coal-fired power plants (CFPP) with photovoltaic, wind power, and hybrid energy storage systems, with particular focus on revealing operational characteristics to inform practical system management. Through assessment of system economics and detailed analysis of seasonal and daily operation characteristics, this study reveals four key findings: (1) The integrated system achieves a 12 % reduction in levelized cost of electricity (0.563 vs. 0.643 CNY/kWh) while maintaining specific CO2 emission comparable to natural gas power (349g CO2/kWh); (2) Specific CO2 emission exhibit distinct temporal patterns, reaching minimum levels during summer daylight hours (10:00–18:00), primarily influenced by renewable resource availability and power demand fluctuations; (3) The proposed optimized CFPP operation strategy featuring lower load during daytime and higher load during nighttime demonstrates effective peak-shaving capability and improved system reliability during peak consumption periods; (4) Battery energy storage system primarily handles daily peak-shaving with predictable operation characteristics conducive to battery health maintenance, while the thermal energy storage system effectively compensates for renewable energy fluctuations and power demand variability. These findings highlight potential pathways for integrated system optimization, suggesting that future efforts could focus on time-dependent emission control strategies, enhanced flexibility in coal plant operation, and storage system management approaches considering equipment health implications. The results demonstrate how operational characteristics analysis can reveal synergies in conventional-renewable hybrid systems.