Hydrogen-Battery Hybrid Energy System on Repurposed Offshore Platforms for Efficient Clean-Energy Transition

Abstract Due to the rising global energy demand and enhanced awareness of the environmental impact of fossil fuels, the Gulf of America (formerly called the Gulf of Mexico), traditionally known for oil extraction, offers a distinct chance to repurpose the existing offshore infrastructure. With the depletion of oil reserves, it is feasible to adapt previously utilized floating platforms for extraction to generate renewable energy, specifically through wind-generated power and hydrogen production. This adaptation seeks to promote a transport system that is more ecologically friendly in the future. Offshore wind turbines will serve as the principal energy source, while battery storage and hydrogen production will complement the overall system performance and fulfill fuel and electricity demand for sustainable energy generation. The system is divided into two distinct cases, each evaluated for cost, performance, and feasibility, with a focus on minimizing both the Levelized Cost of Energy (LCOE) and the Levelized Cost of Hydrogen (LCOH). The first case examines the integration of offshore wind turbines with hydrogen production. Excess electricity generated by wind turbines is directed toward hydrogen production via electrolysis. The hydrogen produced can be used as fuel for vehicles or transported to the shore via pipelines. The second case investigates a technology that combines wind turbines with battery storage. In Case 1, Particle Swarm Optimization (PSO) optimizes the constraints and efficiency of the electrolyzer in the production of hydrogen, which lowers the OPEX to $9.60 million while keeping the CAPEX at $300.00 million. Thus, hydrogen production reaches an annual 4.72 million kg, giving rise to an LCOH of $7.49/kg with a yearly profit of $9.27 million. Grey Wolf Optimization (GWO), also performing the optimization of efficiency, obtained 4.57 million kg of hydrogen-an LCOH equalling $7.73/kg with a profit of $8.70 million per year. In Case 2, the GWO optimizes the cycles of battery charge and discharge so as to prolong battery life and cut expenses. The battery energy storage system with CAPEX of $225.00 million produces 14.76 million MWh of electricity at an LCOE of $41.50/MWh, making an annual profit of $4.17 million. GWO is balanced and offers a reasonable cost-performance ratio compared to PSO (which gives an LCOE of $41.24/MWh and annual profits of $3.98 million). The implementation of a comprehensive strategy results in a substantial reduction in costs, improved energy efficiency, and a dependable supply of both electric power and hydrogen, emphasizing the benefits of converting offshore oil platforms for clean energy transition. This study explores a clean strategy to enable cost-effective repurposing of offshore O&G platforms. Both cases highlight the economic and technical feasibility of transitioning offshore oil platforms to clean energy systems, demonstrating substantial cost reductions and reliable energy and hydrogen supplies for sustainable energy production.