Energy storage sharing can effectively improve the utilization rate of energy storage equipment and reduce energy storage cost.However, current research on shared energy storage focuses on small and medium
Subsea energy storage is an emerging and promising alternative to conventional floating onboard energy storage. In this review, various potential subsea electricity and hydrogen energy storage solutions for ‘floating offshore wind + hydrogen’ are examined and compared.
Subsea battery energy storage is one such promising solution. Modular Li-ion battery energy storage systems are deployed on the seabed and connected to floating wind turbines and offshore platforms via flexible cables. The seawater can effectively transfer and store the heat generated by the battery energy storage system.
Third, the ocean provides an ideal heat sink and seawater with near-constant temperature is an ideal heat transfer medium, thereby facilitating heat management of energy storage systems. Certainly, it will be more complex to deploy energy storage systems onto the seabed.
After all, high security and reliability are the baseline of energy storage in ‘floating offshore wind + hydrogen’ systems. Second, additional space is necessary if the scale of the energy storage system is very large, thereby lifting the investment. In contrast, these challenges could be avoided by subsea energy storage.
For floating offshore wind farms, it will be safer if the medium- and large-scale battery energy storage systems can be deployed far from the wind turbines and offshore platforms. Subsea battery energy storage is one such promising solution.
The period from 2024 to 2030 will be critical for the long-term competition between subsea energy storage and floating energy storage. More demonstrations, improvements, and innovations should be conducted in this period, especially focusing on the utility-scale demonstrations at sea.
