How big is Canada's transmission network?

OverWatts maps 72,900 km of transmission line in Canada, across 5,708 segments, plus 213 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 Canada's grid?

Most of the mapped network is high voltage (220–379 kV): 45,400 km of 72,900 km. The highest voltage tagged anywhere in the country is 765 kV.

How complete is the grid map for Canada?

Partial — 7.3 km of mapped line per 1,000 km² of land, ahead of 27% 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 Canada?

Hydro-Québec, Hydro One, AltaLink and 5 others are tagged as operators on mapped segments. Operator tags are present on 50% of Canada's segments, so this ranks who is *recorded*, not market share.

What interconnectors connect Canada to its neighbours?

14,828 MW of cross-border transfer capacity to United States, plus 4,100 MW planned. Capacities are from the Global Transmission Database (v1.0, 2023).

Canada · electricity network

Canada power grid

OverWatts maps 72,900 km of Canada's electricity transmission network across 5,708 line segments and 213 substations, the 6th most-mapped grid of 153 countries. Its backbone is high voltage (220–379 kV), carrying 45,400 km — 62% of the mapped length, with the highest tagged voltage at 765 kV. That works out to 7.3 km per 1,000 km² of land — partial OpenStreetMap coverage, ahead of 27% of mapped countries. It is connected to 1 neighbouring grid by 14,828 MW of existing cross-border transfer capacity, with a further 4,100 MW planned.

Open the grid lens →Canada profile →

72,900 km

Mapped transmission line

213

Substations

of 153 mapped grids

14.8 GW

cross-border · 1 neighbours

765 kV

Highest voltage

OpenStreetMap coverage

Partial7.3 km / 1,000 km²ahead of 27% of 153 mapped countries

This grades how completely OpenStreetMap has drawn Canada'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 50% an operator tag.

Mapped line length by voltage

≥765 kV55 km 0%
380–764 kV27,100 km 37%
220–379 kV45,400 km 62%
<220 kV174 km 0%
Voltage untagged218 km 0%

5,708 segments · a segment is credited to the country containing its midpoint, so a border-crossing line counts once, on one side.

14.8 GW existing · 4.1 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

137 GW

Operating generation

Data centres mapped

342

km of line per substation

7.3

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.

Operators tagged on Canada's network

Segment counts from OSM `operator` tags, merged across spellings. Present on 50% of segments — this ranks who is recorded, not market share.

How Canada compares · mapped grid by country

1. People's Republic of China624,300 km
4. Russia165,600 km
5. Brazil160,000 km
6. Canada72,900 km
7. Mexico42,400 km
8. Iran37,700 km

Frequently asked

How big is Canada's transmission network?: OverWatts maps 72,900 km of transmission line in Canada, across 5,708 segments, plus 213 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 Canada's grid?: Most of the mapped network is high voltage (220–379 kV): 45,400 km of 72,900 km. The highest voltage tagged anywhere in the country is 765 kV.
How complete is the grid map for Canada?: Partial — 7.3 km of mapped line per 1,000 km² of land, ahead of 27% 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 Canada?: Hydro-Québec, Hydro One, AltaLink and 5 others are tagged as operators on mapped segments. Operator tags are present on 50% of Canada's segments, so this ranks who is *recorded*, not market share.
What interconnectors connect Canada to its neighbours?: 14,828 MW of cross-border transfer capacity to United States, plus 4,100 MW planned. Capacities are from the Global Transmission Database (v1.0, 2023).

Elsewhere in Canada

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.