Feasibility analysis of decarbonizing coal-fired power plants with 100% renewable energy and flexible green hydrogen production

•Retrofitting coal-fired power plants with renewables and hybrid energy storages.•Flexible green hydrogen production via electrolyzer to tackle energy curtailment.•Multi-regional and multi-temporal feasibility analysis of the carbon-free retrofit.•The carbon-free retrofit is techno-economically feasible in wind-rich regions.•The proposed retrofit in Jilin is more profitable than carbon capture and storage.