Voltage-Aware Grid Aggregation: Expanding the European High-Voltage Network

TL;DR

This paper introduces a voltage-aware grid aggregation method that maintains voltage level distinctions and transformers, improving the accuracy of expansion planning in European energy systems.

Contribution

The authors develop a novel voltage-aware network partitioning approach that preserves voltage levels and transformers, enhancing model accuracy over existing voltage-unaware methods.

Findings

Preserves up to 70% of transformer expansion costs compared to full grid models.

Improves accuracy of investment decisions in aggregated grid models.

Demonstrates effectiveness through a European case study using PyPSA.

Abstract

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.