Energy system optimization models are indispensable for planning the European energy transition. Yet their applicability is constrained by the fundamental trade-off between spatial detail and computational tractability. Modelers often tackle this by spatially aggregating electricity networks. Existing methods, however, neglect differences in voltage levels, reducing them to a single level and thereby overlooking the critical role of transformers in expansion planning. Therefore, we propose a novel voltage-aware network partitioning and aggregation methodology that preserves individual voltage levels and transformers. We demonstrate the effectiveness of this approach and compare it against a voltage-unaware grid aggregation by solving a network expansion problem for a European case study using PyPSA. Our findings show that the proposed methodology preserves up to 70% of the transformer expansion costs in the aggregated model compared to the full grid model, thereby significantly improving the accuracy of investment decisions for transformers in the aggregated grid.
@article{arxiv.2605.13205,
title = {Voltage-Aware Grid Aggregation: Expanding the European High-Voltage Network},
author = {Benjamin Stöckl and Marco Anarmo and Sonja Wogrin and Yannick Werner},
journal= {arXiv preprint arXiv:2605.13205},
year = {2026}
}
Comments
Accepted for IEEE International Conference on the European Energy Market