Techno-economic optimization of offshore green hydrogen with dynamic storage modelling

The global energy transition needs innovative solutions for decarbonizing oil&gas sector, with green hydrogen emerging as a pivotal energy carrier. This master's thesis presents a comprehensive techno-economic analysis of two distinct strategies for integrating green hydrogen into an existing offshore oil and gas platform. The primary objective is to evaluate their technical feasibility and economic viability. Scenario 1 encompasses a complex system integrating green hydrogen production via electrolysis, biomethanation (Power-to-Gas, P2G) utilizing captured CO₂, direct blending with natural gas, and flare for surplus H₂. Scenario 2, conversely, adopts a much more simple approach, focusing only on direct blending of green hydrogen with natural gas, with flaring as the only alternative for excess H₂. Both scenarios are built upon realistic operational profiles, including dynamic wind data for hydrogen production and a dynamic modeling of hydrogen storage. The techno-economic assessment reveals significant differences in capital expenditure (CAPEX), operational expenditure (OPEX), and financial performance indicators (NPV, IRR, Payback Period). The study conclusively demonstrates that, under the analyzed conditions, Scenario 2 (direct blending) is significantly more economically viable than Scenario 1 (biomethanation + blending). This outcome is primarily attributed to the substantial CAPEX and additional OPEX associated with the biomethanation unit and the complex CO₂ capture and handling systems required in Scenario 1. While Scenario 1 offers environmental benefits through CO₂ valorization, its higher cost structure impacts overall profitability and investment recovery time. Both scenarios, however, exhibit high efficiency in hydrogen utilization, with minimal flaring losses.