Abstract
Energy system modelling can be used to provide scenario-based insights in energy system transition pathways. However, data accessibility is a common barrier for the model representation of energy systems, both regarding existing infrastructure, as well as planned developments consistent with current policies. This paper describes the 'Global Transmission Database', the first global dataset covering existing and planned electricity transmission developments between countries and selected regions. The dataset can be used as a starting point for the representation of cross-regional electricity grids globally in energy system models and other computational tools. All data is collected from publicly available sources and combined into a single machine-readable format for convenient application.