(102a) Evaluating the Prospects of Integrating Grid Power in China's Offshore Wind-to-Hydrogen Systems Under a Multi-Objective Perspective

Hydrogen, with its dual functionality as both a chemical feedstock and an energy carrier, plays a critical role in climate mitigation and decarbonization. Utilizing renewable energy for water electrolysis is crucial for achieving carbon reduction targets. Over 30 nations have established hydrogen roadmaps, with China releasing its strategic commitment named “Medium and Long-Term Plan for the Development of the Hydrogen Energy Industry (2021–2035)” in 2022.

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. Previous researches focused on offshore wind-to-hydrogen production often overlooks the impact of balancing economic and environmental factors on project deployment plans. Additionally, there is a lack of models that consider the temporal and spatial variability of offshore wind power alongside China's time-of-use electricity pricing mechanism from a high-resolution perspective.

Herein, this study proposes a multi-objective optimization model to analyze the economic feasibility and environmental impacts of deploying offshore wind-to-hydrogen in China, integrating life cycle analysis, economic assessment, and GIS analysis results. It reveals the potential of integrating grid electricity in offshore wind-hydrogen systems. Three hydrogen production models are compared, indicating that onshore off-grid hydrogen production shows cost competitiveness only near the coast, with the lowest costs as low as 3.73 $/kg. High curtailment rates of 18.03-65.5% lead to low production efficiency and elevated costs, whereas integrating stable grid electricity can reduce costs to 2.23 - 7.85 $/kg. However, it is critical to control the proportion of grid electricity due to its negative impact on the environment. Multi-objective optimization results suggest that balancing costs and environmental impacts can achieve significant carbon reductions, even at the expense of some economic viability, providing policymakers with comprehensive insights and diverse options. Currently, China has 315,124 km² available for offshore wind-to-hydrogen, where the potential for clean hydrogen and low-carbon hydrogen at costs below 4 $/kg will reach 86.68 and 169.79 million tons, respectively. The promising hybrid hydrogen production will accelerate carbon reduction efforts in China.

The model developed in this study is also applicable to any country aiming to develop offshore wind-to-hydrogen systems. It explores optimal deployment strategies for future development and provides decision-makers with a comprehensive and diverse range of options.