Identifying options for the multi-terminal expansion of the COBRAcable

Abstract

A meshed North Sea offshore electricity grid with high renewable energy penetration, as envisioned by the European Commission, is still at its infancy. Currently, point-to-point high-voltage DC interconnections across borders are already being implemented successfully, but the next steps of expanding these interconnectors with additional terminals to connect to offshore wind farms or other energy facilities are still being researched. This MSc research evaluates the case of the COBRAcable, an interconnector between Denmark and the Netherlands. The COBRAcable presents an interesting and unique case as it the first of its kind and likely involves the expansion of the interconnector in Germany territory. Large uncertainties are present due to different national regulatory regimes, diverse groups of stakeholders with different interests, and stochastic uncertainties due to the variability of renewable energy sources. A socio-economic framework has been designed to address the interdisciplinary nature of the problem of multi-terminal expansions. Scenarios of alternate futures are developed, and Monte Carlo analysis is performed to address the future energy characteristics and stochastic uncertainties respectively. It consists of a linear optimal power flow model where a simplified grid is being tested under multiple expansions that are selected in an expansion portfolio. The results will be quantitative costs and benefits of expansions as compared to a base case. Complementary, a qualitative stakeholder analysis is carried out to address the regulatory uncertainties that are not accounted for by the model.