GRID · SUBSTATIONS
Where the Grid Meets
Between the lines sit the nodes. A substation is where the high-voltage backbone meets itself — the fenced switchyards where lines join, split and step between voltages on the way from the power plants to the cities. This maps the major ones: 6,271 transmission substations at 300 kV and above, the switchyards of the very same backbone the transmission layer draws. Switch both on and the picture completes: the wires, and the junctions that tie them together. They’re drawn as squares in the same voltage colours as the lines, larger and brighter the higher the voltage.
Reading the voltages
A substation’s voltage is the highest the lines meeting there carry. The nodes split into the same four bands as the backbone — the same colours the live map uses, drawn as larger, brighter squares as the voltage climbs. The handful of ultra-high-voltage switchyards are the giants of the grid, where the 765–1,100 kV super-grids of China and India tie together.
Where the nodes are densest
A feel for where the mapped switchyards cluster. As with the lines, these counts follow OpenStreetMap’s coverage as much as the grid itself — richest across the US and Europe, with China’s ultra-high-voltage build-out well represented too — so read them as a guide to what’s mapped, not a definitive league table.
About this data
Every node comes from OpenStreetMap (power=substation, substation=transmission, via the Overpass API, ODbL). OSM holds around 800,000 substations worldwide — the vast majority small local sites under streets — so this deliberately shows only the transmission tier at 300 kV and above: the major switchyards of the same backbone the transmission layer draws. That floor is the brand line as much as a technical one — these are the big public-infrastructure nodes, shown by voltage only; operator and operational detail are never surfaced. Voltage is reliably tagged at this tier (about 96% of these substations), so it’s the colour axis; the rare impossible voltage tag is shown by band only, never with a made-up number. A switchyard mapped as both a point and an area is collapsed to one. Coverage follows where OSM mapping is densest — richest across the US and Europe — so this is a map of the mapped nodes, not a complete census. Snapshot taken 2026-06-25.
MOST COMMON VOLTAGES — 400 kV (1,723) · 500 kV (1,527) · 345 kV (1,455) · 380 kV (774) · 330 kV (403) · 765 kV (91)