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Asset classes
- Transmission Line80,968
- Power Plant32,429
- Substation / Converter7,614
- Oil & Gas Field7,055
- Coal / Uranium Mine5,382
- Pipeline4,951
- Cement Plant3,513
- Data Centre3,283
- Iron & Steel Plant1,293
- LNG Terminal1,198
- Grid Storage965
- Iron Ore Mine949
- Chemical Plant868
- Interconnector704
- Export Terminal519
- Refinery279
- Storage / Tank Farm38
- Oil / Commodity Contract19
- Hydrogen Project18
- Carbon Capture (CCS)16
Chokepoints
New Zealand · electricity network
New Zealand power grid
OverWatts maps 6,451 km of New Zealand's electricity transmission network across 1,164 line segments and 2 substations, the 46th most-mapped grid of 153 countries. Its backbone is high voltage (220–379 kV), carrying 6,439 km — 100% of the mapped length, with the highest tagged voltage at 350 kV. That works out to 23.3 km per 1,000 km² of land — moderate OpenStreetMap coverage, ahead of 63% of mapped countries.
OpenStreetMap coverage
This grades how completely OpenStreetMap has drawn New Zealand'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. 30% of segments carry a real line name and 62% an operator tag.
Mapped line length by voltage
- 220–379 kV6,439 km 100%
- Voltage untagged12 km 0%
1,164 segments · a segment is credited to the country containing its midpoint, so a border-crossing line counts once, on one side.
On the interactive map
Load against the network
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 New Zealand's network
- Transpower New Zealand720 100%
Segment counts from OSM `operator` tags, merged across spellings. Present on 62% of segments — this ranks who is recorded, not market share.
How New Zealand compares · mapped grid by country
- 1. People's Republic of China624,300 km
- 44. Finland6,783 km
- 45. Turkmenistan6,639 km
- 46. New Zealand6,451 km
- 47. Myanmar6,159 km
- 48. Portugal5,975 km
Frequently asked
- How big is New Zealand's transmission network?
- OverWatts maps 6,451 km of transmission line in New Zealand, across 1,164 segments, plus 2 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 New Zealand's grid?
- Most of the mapped network is high voltage (220–379 kV): 6,439 km of 6,451 km. The highest voltage tagged anywhere in the country is 350 kV.
- How complete is the grid map for New Zealand?
- Moderate — 23.3 km of mapped line per 1,000 km² of land, ahead of 63% 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 New Zealand?
- Transpower New Zealand are tagged as operators on mapped segments. Operator tags are present on 62% of New Zealand's segments, so this ranks who is *recorded*, not market share.
Elsewhere in New Zealand
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.