In-situ green hydrogen production from offshore wind farms, a prospective review

To harvest wind energy in deep sea, offshore wind farms are built farther and farther from coast, dramatically increasing cost especially for electricity transmission. To address this, in-situ hydrogen production is promising, which can be transported to shore by pipeline or ship. To date, a few pilot projects have been implemented worldwide while many related studies are conducted in recent literature. In this work, technical feasibility, economic analysis, environmental impact and potential risk of the offshore wind-hydrogen system are reviewed. First, it is found that existing technologies on offshore wind power, water electrolysis, hydrogen storage and transportation are already mature, but their adaption to the changeful ocean environment is still under optimization. Next, the calculated levelized cost of hydrogen indicates that currently it is still too expensive to be profitable, which needs significant reduction from both government support and scale effect. Moreover, this green hydrogen is predicted to obtain much lower global warming potential than conventional grey hydrogen, but the continuous discharge of concentrated brine may disrupt the local ecology. Furthermore, potential risks in project safety and profitability are haunting this new industry. Based on existing academic studies and engineering experience, future development trends are suggested in the end.