Multi-objective perspective: The prospects of integrating grid power in China's offshore wind-to-hydrogen systems

Utilizing renewable energy for water electrolysis is crucial for achieving carbon reduction targets. Limited terrestrial resources and increasing energy demands compel coastal provinces in eastern China to expand planning of offshore wind. Developing offshore wind-to-hydrogen requires a low-cost and stable power source, creating an opportunity for grid electricity integration. To comprehensively assess the prospects of grid connection in accelerating the development of offshore wind-to-hydrogen production, this study proposes a high-resolution techno-economic-environmental optimization framework combining life cycle assessment and GIS-based analysis. Specifically, an optimization model for estimating hydrogen production potential is proposed to complement the large-scale regional analysis. Results show that the minimum cost of off-grid hydrogen reaches 3.5–3.7 $/kg, limited by high curtailment rates of 18–65%. Integrating grid electricity into hydrogen production reduces levelized cost of hydrogen to 2.3–7.9 $/kg but increases carbon emissions to 2.9–17.1 kg CO2/kg H2. Multi-objective optimization results suggest that balancing costs and environmental impacts can achieve significant carbon reductions. Under current conditions, grid connecting hydrogen production demonstrates its potential of 11.38 Mt clean hydrogen or 17.33 Mt low-carbon hydrogen in China at costs below 3 $/kg. It reveals the feasibility of promoting the low-carbon transition of the hydrogen industry in the short term.