The shift to a sustainable energy tomorrow is critical, especially to industries with a large carbon footprint, such as the oil & gas sector. This research investigates the function of Green Certificates (Guarantees of Origin) in greening the Oil & Gas Industry's supply chain, with a particular focus on the role of Green Hydrogen. The decision to explore this topic comes from the critical industry-wide desire for sustainable energy solutions, with the goal of addressing critical gaps in understanding how Green Certificates could encourage the adoption of Green Hydrogen and contribute to the industry's transition to a more sustainable and environmentally conscious future.

Green certificates, also known as Tradable Green Certificates (TGCs), Guarantees of Origin (GOs), or Renewable Energy certificates (RECs), are electronic certificates that verify that one MWh of energy has been produced from renewable energy sources.  Green Hydrogen is introduced as a prospective decarbonization alternative, investigating its properties, potential applications, benefits, and obstacles. Furthermore, the function of Green Certificates is investigated in encouraging renewable energy, explaining its purpose, regulatory frameworks, and market dynamics.

The dissertation employs a multifaceted methodology, incorporating bibliometric analysis, a case study, and a SWOT analysis to comprehensively explore the chosen research area. Initially, a detailed analysis of the literature provides a comprehensive overview of the Oil and Gas Industry's transition to sustainability, highlighting the environmental problems it faces. Thus, 2,693 papers have been selected from the Web of Science database to examine publishing trends and highlight influential publications from 2000 to 2023.

In addition to bibliometric analysis, a case study approach was used, concentrating on Europe's largest green hydrogen endeavor, the NortH2-project. This real-world case study offers useful insights into the practical use and problems of incorporating green hydrogen and green certifications into the supply chain. The NortH2-project, led by Equinor, RWE, Shell, Groningen Seaports Gasunie, and the province of Groningen, is a thorough example of the problems and opportunities inherent in the shift to sustainable energy methods (north2, 2023). The data gathered from the document analysis have been thoroughly investigated utilizing qualitative methodologies in order to discover success drivers and impediments.

Furthermore, a SWOT analysis, based on the case study, was used to assess the multiple factors influencing the incorporation of green hydrogen and green certifications into the oil & gas industry's supply chain. This strategic analysis helps to identify internal and external variables influencing the industry's transition, offering a comprehensive understanding of the difficulties and opportunities involved with the implementation of sustainable energy solutions.

This research reveals major findings by conducting an in-depth investigation of the function of Green Hydrogen in decarbonizing the Oil and Gas Industry's supply chain. It evaluates Green Hydrogen's potential uses in several elements of the supply chain, such as transportation and energy storage, stressing its ability to cut carbon emissions and improve sustainability. Moreover, the study addresses key questions, such as the role and environmental impact of Green Hydrogen, the operation of regulatory frameworks for Green Certificates, and the potential economic and environmental implications of integrating Green Hydrogen into the oil and gas supply chain. Finally, it also looks at the constraints of integrating Green Hydrogen into the supply chain, such as infrastructure requirements and financial considerations.

To sum up. the role of Green Certificates (Guarantees of Origin) in promoting the use of renewable energy, particularly Green Hydrogen, within the Oil and Gas Industry is a primary focus of this research. The analysis shows how Green Certificates encourage the use of Green Hydrogen by offering transparency, traceability, and accountability in renewable energy sourcing. It assesses the possible economic, environmental, and social consequences of incorporating Green Hydrogen and Green Certificates, with a focus on their innovative potential in the industry's sustainability practices. 

The present work combines significant findings from the case study and literature review to provide light on the implications for the oil and gas industry's transition to a sustainable supply chain. It recognizes the study's limitations, acknowledging the dynamic nature of the energy transition landscape, and makes recommendations for future research. Finally, this research adds to the expanding body of knowledge on sustainable energy solutions while also providing practical recommendations to speed the use of Green Hydrogen and Green Certificates in the Oil and Gas Industry, thus allowing the decarbonization of its supply chain.