A Methodology for Sizing Subsea Energy Storage Devices for Offshore Wind-Powered Oil and Gas Platforms

This thesis presents a methodology for sizing subsea energy storage devices for offshore wind-powered oil and gas platforms. This study examines the literature on hybrid energy systems (HES) and subsea energy storage systems (ESS). A subsea energy storage system is proposed as an environmentally friendly and economically feasible solution for power backup. It could be integrated into the power grid of a HES consisting of the ESS, renewable and non-renewable energy sources. It requires an appropriate ESS sizing approach. Two methods of subsea energy storage sizing are presented in this thesis. The first method uses the wind speed expected value. The second method relies on the weather window analysis. Both methods aim to estimate the ESS size capable of working within a chosen period in the power grid of a HES consisting of the wind farm and non-renewable energy source. Correspondingly, the sizing results of an ESS comparing both methods are presented in this work. Finally, initial charging of the device, additional power supply from the shore, and recommendations on future work are discussed. As a result, this study is expected to serve as a guide for planned and existing projects regarding sizing subsea energy storage