GridInspector Methodology

About GridInspector

GridInspector displays the health score of OpenStreetMap (OSM) data for the electricity transmission network across countries worldwide.

This health score is based on two key indicators: Quality and Coverage.

The Quality indicator measures the consistency and accuracy of OSM data. For example: are the voltages correctly entered? Are the lines properly connected? Are the power towers correctly linked to the lines? The methods used to calculate these quality indicators are described below, and some are based on Osmose analysis.

The Coverage indicator compares the total circuit lengths in OSM with official national data, where available. The official data sources used are compiled on this page.

All algorithms used to calculate the indicators and generate the map are available in the following GitHub repositories: This tool was created by Dynartio as part of the MapYourGrid project.

Method for calculation of quality indicators

Line connectivity

A power line is considered **connected** if it links two power substations. If it is connected on only one end, or not at all, it is considered **not connected**. The line connectivity indicator is defined as the ratio of connected lines to the total number of lines.
  • nb_power_line_cable_connected = Number of connected power lines or cables computed by OSM Power Grid Map Analysis.
  • nb_power_line_cable = Number of power lines or cables computed by OSM Power Grid Map Analysis.
value(%) = 100 * nb_power_line_cable_connected / nb_power_line_cable

How to improve this score: Connect power lines to substations at both ends. Make sure lines are connected to appropriate `line_management=*` nodes when relevant.

Grid overall connectivity (without circuits)

Indicates whether the entire network of connected substations is connexe or not. The indicators reflects the number of substations connected in the different components of the graph. It is computed through OSM Power Grid Map Analysis. This indicator does not take circuit relations into account.

How to improve this score: Connect subparts of the national grid together with power lines.

Overall grid connectivity (with circuit relations)

Indicates whether the entire network of substations forms a single connected graph It reflects the number of substations are connected across the different components of the graph. It is computed using OSM Power Grid Map Analysis and takes circuit relations into account. A higher score indicates that a larger share of substations belongs to the main connected component of the network.

How to improve this score: Connect isolated parts of the national grid using power lines or power relation circuits.

"Cables" tag completeness on lines

Indicates the proportion of power lines for which the `cables=*` tag is present.
  • nb_osm_power_line_cable = Number of items that are tagged "power=line" or "power=cable" in OpenStreetMap.
  • nb_osm_power_line_cable_without_cables = Number of items that are tagged "power=line" or "power=cable" in OpenStreetMap and have no "cables"-tag.
value(%) = 100 * nb_osm_power_line_cable_without_cables / nb_osm_power_line_cable

How to improve this score: Tag `cables=*` on power lines.

"Circuits" tag completeness on lines

Indicates the proportion of power lines for which the `circuits=*` tag is present.
  • nb_osm_power_line_cable = Number of items that are tagged "power=line" or "power=cable" in OpenStreetMap.
  • nb_osm_power_line_cable_without_circuits = Number of items that are tagged "power=line" or "power=cable" in OpenStreetMap and have no `circuits=*` tag.
value(%) = 100 * nb_osm_power_line_cable_without_circuits / nb_osm_power_line_cable

How to improve this score: Tag `circuits=*` on power lines.

"Voltage" tag completeness on lines

Indicates the proportion of power lines for which the `voltage=*` tag is present.
  • nb_osm_power_line_cable = Number of items that are tagged "power=line" or "power=cable" in OpenStreetMap.
  • nb_osm_power_line_cable_without_voltage = Number of items that are tagged "power=line" or "power=cable" in OpenStreetMap and have no `voltage=*` tag.
value(%) = 100 * nb_osm_power_line_cable_without_voltage / nb_osm_power_line_cable

How to improve this score: Tag `voltage=*` on power lines.

"Voltage"-tag completeness on substations

Indicates the proportion of power substations for which the "voltage"-tag is present.
  • nb_osm_power_substations = Number of items that are tagged "power=substation" in OpenStreetMap.
value(%) = 100 * nb(OSM power=substation & voltage!='')/ nb_osm_power_substations)

How to improve this score: Tag `voltage=*` on power substations.

Connected power towers

Indicates the proportion of power towers that are connected to a power=line or power=minor_line.
  • nb_oc1_t = number of Osmose-Class1 issues (i.e. Lone power tower or pole) where the concerned node is a power tower.
  • nb_osm_power_tower = Number of nodes that are tagged "power=tower" in OpenStreetMap.
value(%) = 100 * (1 - nb_oc1_t / nb_osm_power_tower)

How to improve this score: Connect power tower on power lines. This solves some of the Osmose-Class1 issues (i.e. Lone power tower or pole).

Completed power lines

A power line is considered completed when both of its ends are connected to another power line, a power portal or a power insulator, or an appropriate line_management node.
  • nb_oc2 = number of Osmose-Class2 issues (i.e. Unfinished power transmission line)
  • nb_osm_power_line = Number of ways that are tagged with "power=line" in OpenStreetMap.
value(%) = 100 * (1 - nb_oc2 / 2*nb_osm_power_line)

How to improve this score: Connect the power line to another line, to a portal or insulator, or to an appropriated line_management node. This solves some of the Osmose-Class2 issues (i.e. Unfinished power transmission line).

Line-to-line voltage consistency

Segments of connected lines must have coherent voltages.
  • nb_oc3 = number of Osmose-Class3 issues (i.e. Connection between different voltages)
value(%) = 100 * (1 - nb_oc3 / nb(connection nodes) )

Connection nodes computed by grid analysis.

Warning: The Osmose-Class3 issue is refering to line connections AND to minor_line connections. It is not possible yet to distinguish line and minor_line in the issue. Thus the indicator is not yet completely consistent regarding the transmission grid.

How to improve this score: Check consistency of line voltages on joining nodes. This solves the Osmose-Class3 issues (i.e. Connection between different voltages).

Line-to-substation voltage consistency

The voltage of a power line should match the voltage of the substations it is connected to.
  • nb_oc7 = number of Osmose-Class7 issues (i.e. Unmatched voltage of line near of substation)
  • nb_line_substation_connection = number of tuple (substation ; connected line) computed by OSM Power Grid Map Analysis.
value(%) = 100 * (1 - (nb_oc7 / nb_line_substation_connection))

How to improve this score: Check the voltage between a power line and the substations it is connected to. This solves Osmose-Class7 issues (i.e. Unmatched voltage of line near of substation).

Estimated spatial coverage of substations

Indicates the proportion of densely populated area surface that is covered by a substation.
  • d = surface of densely populated areas
  • c = surface of densely populated areas not covered by a substation (Hypothesis: coverage radius of a substation = 40 km)
value(%) = 100 * c / d

Population density source = https://data.humdata.org/dataset/kontur-population-dataset-3km