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Public-images-osm logo.svg power = substation
Legacy National Grid Substation - geograph.org.uk - 39134.jpg
A facility which controls the flow of electricity in a power network with transformers, switchgear or compensators. Edit this description in the wiki page. Edit this description in the data item.
Rendering in openstreetmap-carto area
Area power.png
Group: Power
Used on these elements
may be used on nodesshould not be used on waysmay be used on areasshould not be used on relations
Useful combination
Status: approvedPage for proposal

A substation is a facility for controlling the flow of electricity in a power network. Substations can vary in size from small buildings the size of a garden shed, to much larger outdoor installations of the size of many football fields. They normally contain one or more transformers to increase or decrease the voltage, and are linked to the rest of the network by lines or cables.

Although the majority of substations contain transformers and are used for increasing or decreasing the voltage, some only perform more specialist tasks such as switching or compensation.

This tag should not be used for facilities where power is generated - use power=plant or power=generator instead.

How to Map

Tag a node or a area as power=substation. Most substations should be mapped as areas. Very small substations such as small transformer kiosks in residential areas may be mapped as substation nodes, or as transformers.

In a few cases, a single substation is split over multiple sites (for example on either side of a road), and should be tagged as a multipolygon relation.

The operator, maximum voltage, and a reference code are often marked on a sign outside the substation. These can be recorded in the operator=*, voltage=*, and reference=* tags.

Substation vs Transformer

When should a facility be tagged as a substation and when should it be tagged as a transformer? Substations and transformers can be distinguished as follows:

  • power=substation represents an area that may contain transformers. It typically also comprises switchgear and other components.
  • power=transformer represents a transformer device, as a node. Power transformers are mostly found inside substations. However, a small distribution transformer located in a power pole is considered by most people to be a "transformer", not a "substation". A pole-mounted transformer should not be tagged as a substation. See power=transformer for more details.


The most common tags used for substations are:

Key Value Comment Recommendation
power substation The substation should normally be mapped as an area. However, a small distribution substation may also be mapped as a node. mandatory
substation transmission / distribution / etc The role of the substation within the electricity network. recommended
location outdoor (default) / indoor / etc The physical location of the substation. recommended
voltage <voltage>[;<voltage>..] The voltages of the substation, ordered from highest to lowest (e.g. 400000;225000;63000). It is recommended to tag at least the highest voltage of the substation. recommended
gas_insulated yes Whether this substation uses pressurized gas as insulator. Gas insulation is increasingly used in modern high voltage substations. optional
name <name> The name by which the substation is known. recommended
operator <operator> Name of the company that operates the substation. optional
ref <reference> Abbreviation / reference number of the substation. optional

The location=* tag may also be used together with power=transformer and other components of a substation when their location differs from that of the substation.
location=kiosk has been used to tag compact distribution substation located in small enclosures where technicians cannot enter to work. man_made=street_cabinet + street_cabinet=power is more suitable for such objects.

Substation Components

It's possible to map the components within substations, especially for larger outdoor facilities. A typical substation comprises at least the following components:

Substation-diagram.png Gray: Substation
Cyan: Power line
Blue: Bay
Green: Switches etc
Purple: Busbar assembly
Red: Transformer

Power Lines: Busbars & Bays

Power lines within a substation are further categorised into line=busbars and line=bays, with the busbar being the central, high-current connection point of the substation.

There is normally one set of busbars per voltage level, with the higher-voltage busbar being the largest and most visible due to the larger conductor spacing. Bays are lines which run off the busbar to connect to transformers or power lines, usually via a combination of circuit breakers, disconnectors, and instrument transformers.

Lines in substations are almost always in groups of three, with one conductor per phase. These can be tagged as a single way (power=line, cables=3), or individually.

Other Components

LOADING TAG LIST... (If you do not see this tag list, you need to enable Javascript)

This table is auto-generated. See Taginfo/Taglists for a documentation on it.


Maperitive OSM Carto Tagging Note
red:400kV, blue:132kV,
purple:converter,DC line/cable,
yellow:transformer, black:switch,
red circle:reactor, read area:filter
Standard OSM Carto rendering
name=Bjæverskov HVDC Kontek

(valve hall)
name=HVDC Kontek
rating=600 MW
Bjæverskov HVDC substation in Denmark (northern terminal of Kontek HVDC connection).
Bing imagery of the substation.
Photo Tagging OSM Carto Note
Bleiswijk-380kv-photo.jpg areapower=substation
name=380kV Bleiswijk
380kv-bleiswijk-mapnik.png 380 kV substation with three 380/150 kV transformers. Unusual for using outdoor gas insulated switchgear (GIS).
Indoor 25/10kV substation, Wateringen areapower=substation
25kv-substation-mapnik.png Indoor 25/10kV substation near The Hague. The entire fenced area should be mapped as a substation, not just the building.
Transformer cabinet, Netherlands nodeman_made=street_cabinet
An example of a small kiosk type substation.
Pole mounted transformer Uldum, Denmark nodepower=pole
Typical pole mounted 10 kV transformer.
Transformer house, Germany areapower=substation
Characteristic tower type transformer building functioning as an electricity pole.
Service building.png area power=substation


Typical minor distribution station located in a small masonry building.

Tools using this scheme

See also

Possible tagging mistakes

If you know places with this tag, verify if it could be tagged with another tag.
Automated edits are strongly discouraged unless you really know what you are doing!
If you know places with this tag, verify if it could be tagged with another tag.
Automated edits are strongly discouraged unless you really know what you are doing!