Robust Transmission Planning: An Application to the Case of Germany in 2050

Technological advances and climate considerations drive substantial changes within the electricity sector. Yet, these changes, although their thrust might be intuitive, are subject to large uncertainties: Technologies may be available earlier or later, international/regional co-ordination may work better or worse etc. This poses significant challenges to the task of transmission planning: Therefore, in this paper, we analyze how these uncertainties may impact transmission planning and how these impacts can be mitigated. We put a special focus on 'robust' optimization techniques and analyze a stylized model of Germany in 2050. We find, somewhat counter-intuitively, that 'classical' robust optimization techniques may lead to imbalanced decisions, focusing on only one of several possible realizations, especially when the absolute impact of the exogenous uncertainties leads to strongly differing costs. In that case, minimizing the maximum regret may be more preferable. Overall, we find evidence that techniques of robust transmission planning allow for savings in transmission investment and power system operations.