Decommissioning Platforms to Offshore Solar System: Road to Green Hydrogen Production from Seawater

With more than 140 offshore platforms identified in Malaysian water to be decommissioned within 10 years, it is critical for the Oil and Gas operators to re-evaluate the overall decommissioning strategies for a more sustainable approach. A revision to the current decommissioning options with inclusion of green decommissioning plan to the overall decision tree will assist in accelerating sustainable decision making. Using the advantage of the available 3D modelling from Naviswork and convert to PVSyst software for solar analysis to the one of the shortlisted offshore gas complexes in Malaysia, three solar powered generation scenario was evaluated with aimed to establish the best integrated system on a modified decommissioned unmanned processing platform to generate cleaner energy. Financial assessment inclusive of Levelized Cost of Electricity, as well as environmental assessment for each scenario are evaluated together. From the study, optimum tilt angle was determined, resulted to best annual solar yield of 257MWh with performance ratio (PR) of 87% for on-grid scenario 1. Off-grid scenario 3 is used to understand the estimated green hydrogen production. A desktop investigation conducted to three (3) type of electrolysers resulted to 8.6 kg to 18 kg of green hydrogen based on the average daily solar yield produced in scenario 3. Using Proton Electron Membrane electrolyser to simulate the PV solar-to-hydrogen offshore system, it is observed that 98% of annual solar fraction can be achieved, with annual performance ratio of 74.5% with levelized cost of Hydrogen (LCOH) of $10.95 per kg. From financial assessment, this study justifies platforms repurpose to renewable energy concept to be an attractive option since cost to decommission the identified complex was observed to be 11 times greater compared to investing for this proposed concept.