Investigating the impact of unanticipated market and construction delays on the development of a meshed HVDC grid using dynamic transmission planning

This study presents a market-based dynamic transmission planning framework for the construction of a meshed offshore voltage source converter-high voltage direct current (VSC-HVDC) grid. Such a grid is foreseen for integrating offshore wind and electricity trade functions among the North Sea countries. The proposed model seeks to maximise the social welfare of all zones and to minimise the investment capital of transmission infrastructure subject to technical and economic constraints. It determines the optimal grid design, including grid topology and transmission capacities for each development stage. The transmission capacities are set in such a way that congestion revenues collected throughout the lifetime of the infrastructure project pay off the investment cost of building the grid. The model is used to investigate the impact of unanticipated delay constraints due to technical (e.g. unavailability of DC breakers), economic (e.g. supply chain shortages) and legal obstacles (e.g. heterogeneous permitting criteria). It is quantified how (i) longer delays result in larger social welfare losses; (ii) different countries will be affected differently by the delays and so have unequal incentives for solving them; (iii) the length of the delay affects the capacity of cross-border connections. Numerical results are interpreted in economic terms and allow appraisal of the effectiveness of the proposed approach.