ABSTRACT
We extend the equal load-sharing model of cascades to investigate the abrupt breakdown behavior of coupled distribution grids. In particular, we mimic the effects of the ever-increasing customer demand in a foreseen scenario where energy hubs interconnect the different energy vectors. In the load growth scenario we find evidence of first order transitions (i.e. abrupt breakdowns of the system) due to the long-range nature of the flows. Our results indicate that the foreseen increase in the couplings between the grids has two competing effects: on the one hand, it increases the safety region where grids can operate without withstanding systemic failures; on the other hand, it increases the possibility of total failure of all the interconnected systems at once.
