Multi-criteria approach to transmission expansion planning in Europe

The challenge of worldwide energy decarbonisation is crucial to ensure a sustainable development, whose achievement needs higher deployment of renewable sources and electrification of final uses. To reach clean energy transition goals, transmission system covers a fundamental role, and transmission grid improvements are crucial to ensure higher renewable integration and increase network flexibility and reliability. Research on transmission expansion planning has been so far dominated by energy economics and power system engineering, implementing model-based scenarios through techno-economic simulations with the objective of costs minimization. However, transmission expansion planning involves a large number of stakeholders, with diverse objectives and interests, asking to address this topic with a more multi-disciplinary approach, which should be reflected into a decision-making prompt to articulate a policy framework representing a compromise among different objectives. Focusing on European dimension, the study is intended to review the possible drivers and barriers to the development of the electricity interconnection projects, approaching it as a socio-technical system, term that indicates a system where social, economic and political elements are integrated into the planning and operation of technological systems. Aiming to identify the main influencing factor, stakeholder analysis is performed, highlighting the main players in transmission expansion planning and defining their interests in the realization of the projects. To fully describe the issue, threats and barriers should be also studied, researching for criteria able to depict them. Through this analysis, it is possible to identify multiple criteria, belonging to diverse domains (social, political, economic, environmental, technical), which should the basis for decision-support methods, as multi-criteria decision analysis (MCDA), which are widely used tools for supporting the policy decision-making process in complex energy planning.