Identification of Technical Design Constraints and Considerations for Transmission Grid Expansion Planning Projects

TL;DR

This paper systematically identifies and classifies key technical constraints and considerations for planning large-scale transmission grid expansions, especially for offshore wind integration, providing a structured decision-making framework.

Contribution

It introduces a hierarchical classification of constraints and considerations, enhancing transparency and systematic planning for transmission grid expansion projects.

Findings

Seven key areas of interest identified and analyzed

Hierarchical classification of constraints into hard, main, and key considerations

Discussion of dependencies between different planning areas

Abstract

The large-scale deployment of renewable energy sources, particularly offshore wind, requires large-scale transmission grid expansion projects to transmit the produced low-carbon power to the main demand centers. However, the planning and design of such complex projects currently lack a transparent and systematic process that system operators can follow when considering such investments in their grids. This paper identifies and classifies the main technical design constraints and considerations relevant to the planning of transmission grid expansion projects, and more specifically, electrical energy hubs. Seven key areas of interest are identified, namely network integration, HVDC technologies, costs (CAPEX, OPEX, and space requirements), electricity market design, future proofness and modular expandability, reliability-availability-maintainability, and sustainability. Each area of interest is analyzed in terms of its technical and operational relevance, with technical design constraints and considerations derived from such analysis. In addition, a hierarchical classification of the identified constraints and considerations (and therefore areas of interest) is introduced, distinguishing them between three criticality classes, namely hard constraints, main drivers, and key considerations. The dependencies between the different areas are discussed, too. Therefore, this work provides system operators and policymakers with a structured basis to support a transparent planning methodology with clear decision hierarchies for investments in transmission grid expansion projects.