How big is Spain's transmission network?

OverWatts maps 29,800 km of transmission line in Spain, across 4,672 segments, plus 240 substations. This is mapped length from OpenStreetMap, not an operator-reported total — where OSM is incomplete the figure is a floor, never a ceiling.

What voltage is Spain's grid?

Most of the mapped network is extra-high voltage (380–764 kV): 14,900 km of 29,800 km. The highest voltage tagged anywhere in the country is 1,320 kV.

How complete is the grid map for Spain?

Strong — 59.4 km of mapped line per 1,000 km² of land, ahead of 93% of the 153 countries with any mapped grid. Coverage grades how completely OpenStreetMap has drawn the network, not how much network exists; large, sparsely-populated countries score low for geographic reasons alone.

Who operates the grid in Spain?

Red Eléctrica de España, Movhera, REN and 5 others are tagged as operators on mapped segments. Operator tags are present on 52% of Spain's segments, so this ranks who is *recorded*, not market share.

What interconnectors connect Spain to its neighbours?

8,900 MW of cross-border transfer capacity to France, Portugal, Algeria, Morocco, plus 7,100 MW planned. Capacities are from the Global Transmission Database (v1.0, 2023).

Spain · electricity network

Spain power grid

OverWatts maps 29,800 km of Spain's electricity transmission network across 4,672 line segments and 240 substations, the 12th most-mapped grid of 153 countries. Its backbone is extra-high voltage (380–764 kV), carrying 14,900 km — 50% of the mapped length, with the highest tagged voltage at 1,320 kV. That works out to 59.4 km per 1,000 km² of land — strong OpenStreetMap coverage, ahead of 93% of mapped countries. It is connected to 4 neighbouring grids by 8,900 MW of existing cross-border transfer capacity, with a further 7,100 MW planned.

Open the grid lens →Spain profile →

29,800 km

Mapped transmission line

240

Substations

#12

of 153 mapped grids

8.9 GW

cross-border · 4 neighbours

1,320 kV

Highest voltage

OpenStreetMap coverage

Strong59.4 km / 1,000 km²ahead of 93% of 153 mapped countries

This grades how completely OpenStreetMap has drawn Spain's network — not how much network exists. Large, sparsely-populated countries score low for geographic reasons alone, and every kilometre here is mapped length, so the totals are a floor rather than an operator-reported figure. 9% of segments carry a real line name and 52% an operator tag.

Mapped line length by voltage

380–764 kV14,900 km 50%
220–379 kV14,800 km 50%

4,672 segments · a segment is credited to the country containing its midpoint, so a border-crossing line counts once, on one side.

8.9 GW existing · 7.1 GW planned · capacities from the Global Transmission Database v0.1 (CC BY 4.0), existing as of 2023

On the interactive map

Open the interactive map →

Load against the network

65.9 GW

Operating generation

Data centres mapped

124

km of line per substation

59.4

km per 1,000 km²

Where there is room to connect a new load depends on published hosting capacity, which most operators release only as their own map. OverWatts does not yet ingest those feeds, so these are the density measures the open data supports — generation and mapped demand against mapped network — not a headroom figure.

Segment counts from OSM `operator` tags, merged across spellings. Present on 52% of segments — this ranks who is recorded, not market share.

How Spain compares · mapped grid by country

1. People's Republic of China624,300 km
10. South Africa33,200 km
11. Kazakhstan31,900 km
12. Spain29,800 km
13. Saudi Arabia27,300 km
14. Australia24,400 km

Frequently asked

How big is Spain's transmission network?: OverWatts maps 29,800 km of transmission line in Spain, across 4,672 segments, plus 240 substations. This is mapped length from OpenStreetMap, not an operator-reported total — where OSM is incomplete the figure is a floor, never a ceiling.
What voltage is Spain's grid?: Most of the mapped network is extra-high voltage (380–764 kV): 14,900 km of 29,800 km. The highest voltage tagged anywhere in the country is 1,320 kV.
How complete is the grid map for Spain?: Strong — 59.4 km of mapped line per 1,000 km² of land, ahead of 93% of the 153 countries with any mapped grid. Coverage grades how completely OpenStreetMap has drawn the network, not how much network exists; large, sparsely-populated countries score low for geographic reasons alone.
Who operates the grid in Spain?: Red Eléctrica de España, Movhera, REN and 5 others are tagged as operators on mapped segments. Operator tags are present on 52% of Spain's segments, so this ranks who is *recorded*, not market share.
What interconnectors connect Spain to its neighbours?: 8,900 MW of cross-border transfer capacity to France, Portugal, Algeria, Morocco, plus 7,100 MW planned. Capacities are from the Global Transmission Database (v1.0, 2023).

Elsewhere in Spain

Transmission lines Substations Power plants Data centres

Network geometry: OpenStreetMap (ODbL) © OpenStreetMap contributors, ingested and measured by OverWatts · derived 2026-07-26. Counts every mapped line of 220 kV and above; the map layer draws the ≥380 kV backbone only, so it shows less than is measured here.