Levelized Cost of Storage Analysis of Subsea Isobaric Hydrogen Storage

Abstract

Floating offshore wind-based green hydrogen production has emerged as a viable alternative to conventional electricity generation and transmission. Large scale, long duration offshore hydrogen storage is a critical component. A subsea isobaric hydrogen storage concept is proposed in this study. A detailed levelized cost of storage (LCOS) analysis is conducted from the perspective of life cycle assessment for the first time. The findings yield several new insights and provide recommendations for optimizing the techno-economic performance of subsea isobaric hydrogen storage technology. Transportation and installation costs are significant contributors to overall expenses. In the benchmark scenario with a 200-m water depth and a weekly cycling rate, the calculated LCOS is 0.52 USD/kg H₂, which is substantially lower than that of conventional pressurized container storage with the value of 1.33 USD/kg H₂. And the LCOS decreases with the increasing water depth. The LCOS is 0.14 USD/kg H₂ when the water depth is 800 m. Sensitivity analysis reveals that the LCOS is primarily influenced by the hydrogen storage accumulator, while the impact of the wind farm is marginal. The LCOS demonstrates high sensitivity to water depth of storage, storage volume per hydrogen accumulator, and the lifetime of hydrogen accumulators. These results provide valuable guidance for the design and deployment of cost-effective subsea isobaric hydrogen storage systems.

Keywords

Green hydrogen / Offshore renewable energy / Levelized cost of storage / Hydrogen storage / Subsea / Isobaric / Energy storage / Offshore wind

Statement of the Use of Generative AI and AI-Assisted Technologies in the Writing Process

During the preparation of this manuscript, the authors used DeepSeek in order to check spelling, grammar, punctuation, and typographical errors within the manuscript. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the published article.

Author Contributions

Conceptualization, Z.W., P.L., T.S., D.S.-K.T., R.C. and W.X.; Methodology, Z.W., T.S., D.S.-K.T. and R.C.; Software, Z.W.; Formal Analysis, Z.W., Z.Z., H.W. and P.L.; Investigation, Z.W., Z.Z. and H.W.; Resources, P.L. and W.X.; Data Curation, Z.W., Z.Z. and H.W.; Writing—Original Draft Preparation, Z.W. and Z.Z.; Writing—Review & Editing, T.S., D.S.-K.T., R.C. and W.X.; Visualization, Z.W.; Supervision, W.X.; Project Administration, Z.W. and W.X.; Funding Acquisition, W.X.

Ethics Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data generated during and/or analyzed during the current study are available from the corresponding author on request.

Funding

This research was funded by the National Natural Science Foundation of China [No. 52075065].

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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