The grid's load-bearing nodes

Delete one substation from the map and ask what is still connected. In the mapped transmission network, 28,823 substations are structural single points: remove one and some part of the network can no longer reach the rest, with up to 128 GW of attached generation sitting on the severed side. This page ranks them. It measures network shape, not electrical operation; a cut vertex is a place that deserves an N-1 look, never an outage forecast.

Highest-severity single points

country

substation	country	kV	severed substations	severed generation (MW)

severity = substations and attached generation cut off from the component's main body if this node is removed; names are OSM-sourced and often absent; shown as unnamed, never invented

Where the single points concentrate

See the live siting screen Screen a shortlist

Method & receipt. Universe: the mapped line topology; Substation-to-Substation connections from OpenInfraMap/OSM (78,786 networked substations; substations with no mapped line are out of scope). Articulation points and bridge lines are computed exactly (igraph, igraph_articulation_bridges_v1); severity counts the substations on the severed side and the generation MW attached to them (a generator connected to k substations contributes mw/k to each; no double counting). Honesty: this is graph topology, not a load-flow study. Re-dispatch, lower-voltage paths, switching and any line missing from the map all add real redundancy this method cannot see; treat every row as a screening candidate for N-1 review, not a vulnerability claim. Coverage inherits the map: dense in Europe/North America/China, thinner elsewhere; OSM name gaps are shown as unnamed. Source: GET /v2/spatial/grid-criticality · methodology · sources.