A large-scale power-to-H2-to-power system adopting hydrogen mixed gas turbine for wind accommodation: Process modeling, optimal dispatch and economic feasibility analysis

The high percentage of renewable energy penetration poses volatility and intermittency challenges, making it imperative to explore pathways for large-scale green hydrogen production and utilization. In the present work, a novel power-to-H 2 -to-power (PtH2tP) system is proposed for onshore wind accommodation, incorporating hydrogen mixed gas turbines (HMGTs). An innovative methodology integrating economic and carbon emissions assessment with optimal dispatch is developed, in which the HMGT off-design operational characteristics and policy compensation for green hydrogen are considered. A case study in China demonstrates the feasibility of the PtH2tP system in achieving flexible energy conversion and hydrogen self-sufficiency. Particularly, a levelized cost of electricity of 0.0537 €/kWh and carbon emissions of 0.29 kg CO 2 eq/kWh are observed. The fuel consumption of HMGTs and purchased grid electricity are significant contributors to carbon emissions. A comprehensive sensitivity analysis indicates an optimal hydrogen substitution ratio of 31% as the threshold for balancing economics and environmental benefits. • A PtH2tP system incorporating onshore wind turbines and HMGTs is proposed. • The LCOE for implementing the PtH2tP system in Yulin, China is 0.0537 €/kWh. • Carbon emissions are attributed to HMGT's fuel and purchased grid electricity. • The optimal hydrogen substitution ratio of 31% is discovered in the case studied.