Power generation/Guidelines/Thermal plants
Covered features
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This documentation offers practical guidance for mapping fossil fuels and biomass thermal power plants, including coal, gas, waste-to-energy, and combined heat-and-power facilities.
There is debate over whether nuclear power plants count as thermal plants. Although their heat source is nuclear fission rather than fuel combustion, they share many features such as turbine halls, chimneys, and cooling towers. For convenience, and because their mapped components are similar, this documentation includes nuclear power plants.
Covered elements include the main plant site, turbines, chimneys, cooling towers, storage areas, water intake and treatment structures, and generation substations.
This documentation does not cover :
- Mobile or small-scale heating systems, household boilers, or standalone backup generators ;
- Geothermal power plants : which are covered on this page : Geothermal plants.
- Solar thermal power plants, which are covered on this page : Solar plants.
The aim of this documentation to ensure consistent, high-quality mapping, especially during organised editing. Accurate tagging helps support research, planning, and energy transition projects.
Power generation facilities are industrial sites, typically closed to the public and posing serious risks such as electrical hazards, heat, exposure to chemicals, or death.
Information gathering on-site should always be done safely and in full compliance with local regulations and warning signs. You must never enter restricted or hazardous areas, and this documentation does not encourage or expect you to trespass fences or gates under any circumstances.
Thermal plants
Technology:
Technology: Thermal power plants generate electricity by converting heat from fuel combustion (conventional thermal plants) or nuclear fission (nuclear plants) into mechanical energy.
- In conventional thermal plants, fuel such as coal, oil, gas, biomass, or waste is burned in a boiler or combustion chamber. The heat produces steam or hot gases, which drive a turbine connected to an electrical generator.
- In nuclear plants, the heat is generated by nuclear fission in a reactor core, with steam delivered to turbines in much the same way.
Some plants are designed for cogeneration of combined heat and power (CHP), thus supplying electricity and heat for district heating or industrial processes.
- Conventional thermal plants CHP are very common for district heating networks, industrial processes, etc.
- Nuclear CHP is technically feasible but less common (only 43 nuclear reactors in total in the world are CHP) because of safety regulations and distance between nuclear sites and urban centers.
These plants include:
| Type of plant | Photo | Satellite image | Name of the plant | Coordinates |
|---|---|---|---|---|
| Coal-fired power plant |
 |
 |
Bełchatów Power Station, Poland | 592157961 592157961
|
| Oil-fired power plant |  |
 |
Hsieh-ho Power Plant, Taiwan | 10757938 10757938
|
| Gas-fired power plant | (photo not available) |  |
Qurayyah IPP, Saudi Arabia | 196903045 196903045
|
| Biomass power plant |  |
 |
Drax Power Station, UK | 34383063 34383063
|
| Waste-to-energy power plant |  |
 |
EEW Energy from Waste Premnitz GmbH, Germany | 747892905 747892905
|
| Nuclear power plant | .jpg) |
 |
Kori Nuclear Power Plant, South Korea | 1270612144 1270612144
|
In satellite imagery:
Thermal power plants can be identified in aerial imagery by the following features :
- A cluster of large industrial buildings (that are housing boilers and turbine halls) ;
- Tall chimneys, visible with long shadows ;
- Cooling towers, often in a typicall hyperboloid shape ;
- Fuel-storage areas (coal piles, oil tanks, biomass silos);
- Water tanks or discharge structures ;
- On-site substations.
Most thermal plants with steam cycles are located near a body of water, because they need significant amounts of water for cooling purposes. On satellite imagery, they are often easy to spot as large industrial complexes situated right next to rivers, lakes, or coastlines.
However, there are exceptions : some plants use air-cooled condensers instead of water, and facilities in arid regions may rely on dry cooling systems or hybrid designs to reduce water demand.
To illustrate the different features of a thermal power station, let's take a look at the Ratcliffe-on-Soar Coal-Fired Power Station in the UK (coordinates 52.8655526, -1.2551273).
| Features | Ground photo | Satellite image | Recommended tags | Example |
|---|---|---|---|---|
| Chimneys |  |
 |
building=industrial, man_made=chimney
|
116297653 116297653
|
| Cooling towers |  |
 |
building=industrial, man_made=tower, tower:type=cooling
|
112702913 112702913
|
| Fuel-storage areas |  |
 |
man_made=heap, resource=coal
|
464983902 464983902
|
| Water management systems | (photo not available) |  |
natural=water
|
55087289 55087289
|
| On-site substation |  |
 |
power=substation
|
55087251 55087251
|
Grid connection:
Thermal power plants are connected to the electrical grid through an on-site power substation, where the electricity generated by the turbines is stepped up to higher voltages for transmission.
Large thermal plants can have a dedicated substation located inside the fenced area of the plant, connected directly to the turbine hall by busbars or underground cables.
Unlike solar plants or wind farms, where a substation collects output from many small generation units, a thermal plant typically feeds the substation from a single generation block (one or several turbines working together). This makes the plant–substation relationship more direct and easier to map.
How to map
Closed perimeter
Thermal power plants should be mapped as 
and should represent the physical extent of the installation as seen on satellite imagery.
If you are certain that the same plant spans across multiple non-contiguous areas, use a type=multipolygon relation and apply all plant-related tags to the relation, not to each individual area.
These facilities are typically enclosed by a fence or wall for security and restricted access. You can map and tag this perimeter using the appropriate barrier=*.
Recommended tags: Tagging differs between technologies of thermal power plants but the following can be used in every situation:
Tags according to the type of thermal plant:
| Coal-fired power plant | Oil-fired power plant | Gas-fired power plant | Biomass power plant | Waste-to-energy power plant | Nuclear power plant | |
|---|---|---|---|---|---|---|
plant:source
|
coal
|
oil
|
gas
|
biomass
|
waste
|
nuclear
|
plant:method
|
combustion
|
combustion
|
combustion
|
combustion gasification
|
combustion gasification
|
fission
|
Additional tags:
name=*operator=*start_date=*plant:output:electricity=*and/orplant:output:heat=*
Roads
Paths and roads allow technicians to move safely between equipment.
They should be mapped as ways and tagged with highway=service and access=private.
Buildings
Visible buildings within the plant site should be mapped as and tagged at least with building=industrial.
Distinctive structures such as turbine halls, boiler houses, or storage tanks should be tagged appropriately.
Storage tanks
Recommended tags:
When mapping:
Storage tanks should be mapped as and should represent the physical extent of the installation as seen on satellite imagery.
In satellite imagery, they typically appear as large cylindrical tanks with flat or domed roofs with circular shadows, or as tall vertical silos. Oil tanks may show floating roofs with visible seams or dark rings, while biomass silos are usually slimmer and clustered near conveyor belts.
Chimneys
Recommended tags:
When mapping:
Chimneys should be mapped as a as a 
or, if the imagery allows it, as a circular , following the base footprint of the structure. If the plant has multiple chimneys, each one should be mapped individually.
Cooling towers
Recommended tags:
When mapping: Cooling towers should be mapped as a circle {Icon|Area}, following the base footprint of the structure. If the plant has multiple towers, each one should be mapped individually.
Generators
The mapping approach of generator is the same across different types of thermal power plants, but tagging differs depending on the heat source.
- In conventional thermal power plants, generators are usually steam turbines or gas turbines.
- In nuclear power plants they are steam turbines driven by heat from the reactor.
Generators are always housed inside buildings (turbine halls or boiler rooms) and cannot be distinguished by turbine type from aerial or satellite imagery. So while the generator halls themselves are visible on satellite imagery as large rectangular industrial buildings, the turbine technology, steam or gas, must be inferred from external data.
Recommended tags:
Tags according to the type of thermal plant:
| Coal-fired power plant | Oil-fired power plant | Gas-fired power plant | Biomass power plant | Waste-to-energy power plant | Nuclear power plant | |
|---|---|---|---|---|---|---|
generator:source
|
coal
|
oil
|
gas
|
biomass
|
waste
|
nuclear
|
generator:method
|
combustion
|
combustion
|
combustion
|
combustion gasification
|
combustion gasification
|
fission
|
generator:type
|
steam_turbine
|
steam_turbine gas_turbine
|
steam_turbine gas_turbine
|
steam_turbine gas_turbine
|
steam_turbine gas_turbine
|
steam_turbine
|
Additional tags:
name=*operator=*start_date=*generator:type=*generator:output:electricity=*and/orgenerator:output:heat=*
When mapping:
Generators are mapped as a placed in the middle of the generator halls that are mapped as a and tagged with building=industrial. Do not confuse the building enclosing the generator with the generator itself.
Generation substation
Power plants are connected to an on-site power=substation, which feeds the electricity into the transmission network.
Recommended tags:
power=substation
substation=generation
Additional tags:
name=*voltage=*operator=*operator:wikidata=*start_date=*
When mapping: For detailed guidelines on mapping substations and substation equipment, please refer to the dedicated wiki page : Power networks/Guidelines/Substations