# Chapter V. Energy flows ## A. Introduction 5.1. The objective of this chapter is to describe energy flows and the main groups of economic units that are relevant for the collection of data on such flows. In particular, this chapter provides a description of energy industries and energy consumers and presents a cross-classification of energy consumers and energy uses. The concepts and definitions introduced in this chapter complement the concepts, definitions and classifications introduced in chapters III and IV and provide a foundation for the identification of data items, the formulation of data collection and data compilation strategies and the compilation of energy balances that are described in chapters VI, VII and VIII. ## B. Concept of energy flows 5.2. In the context of basic energy statistics and energy balances, the term "energy flow" refers to the production, import, export, bunkering, stock changes, transformation, energy use by energy industries, losses during the transformation, and final consumption of energy products within the territory of reference for which these statistics are compiled.[^38] This territory generally corresponds to the national territory; however, it can also refer to an administrative region at the sub-national level or even to a group of countries. The term "rest of the world" is used here to denote all areas/territories outside the reference territory. 5.3. The first appearance of an energy product in the territory of reference is either through its production or import. Whereas some energy products may be used directly in the form they were captured from the environment, many energy products undergo some sort of transformation before final consumption. This is the case, for example, with the processing of crude oil in petroleum refineries, where the oil is transformed into a range of products that are useful for specific purposes (e.g., gasoline for transportation). 5.4. Once produced and/or transformed, energy products can be: (a) exported to other territories; (b) stored for later use (entering into stock); (c) used for refuelling of ships and airplanes engaged in international voyages (international bunkering); (d) used by the energy industries themselves; and/or (e) delivered for final consumption. 5.5. The final consumption of energy products consists of (a) final energy consumption, i.e. deliveries of energy products to the users located in the territory of reference for their energy needs, such as for heat raising, transportation and electricity, and (b) non-energy use, i.e. deliveries of energy products for use as chemical feedstocks or as raw materials (see para. 5.21 for details). 5.6. For energy policy and analytical purposes, the final energy consumption is further disaggregated according to type of economic activity, while the use of energy products for the purpose of transport is identified independently from the economic sector in which they were consumed. 5.7. A diagram representing the main energy flows is presented in figure 5.1 below, while their definitions are provided in the subsequent sections of the chapter. > **Figure 5.1 — Diagram of the main energy flows** > > Rest of the world: Exports; Imports; International aviation and marine bunkering. > > Reference territory: Stocks; Production of primary products → Transformation → Final consumption for energy and non-energy purposes (e.g., Agriculture, forestry and fishing; Mining and quarrying; …; Households). > > Exports and Imports connect the reference territory to the rest of the world; international aviation and marine bunkering is shown between production/transformation and the rest of the world. > > 5.8. Energy flows and economic units. Energy flows are generated by the activities of various economic units. These flows are defined in section C below. Depending on their role in the flow of energy through the economy, the economic units can be categorized as energy industries, other energy producers and energy consumers. This will be presented in sections D, E and F, respectively. ## C. Definition of main energy flows 5.9. This section provides definitions and explanations of the main energy flows. Note that the definitions presented here are the result of the work of the InterEnerStat and have been reviewed and supported by the Oslo Group on Energy Statistics and the United Nations Expert Group on Energy Statistics. It is recommended that countries follow these definitions in their official energy statistics as closely as possible. Any deviations should be reflected in countries' energy metadata. 5.10. Production is defined as the capture, extraction or manufacture of fuels or energy in forms that are ready for general use. In energy statistics, two types of production are distinguished, primary and secondary. Primary production is the capture or extraction of fuels or energy from natural energy flows, the biosphere and natural reserves of fossil fuels within the national territory in a form suitable for use. Inert matter removed from the extracted fuels and quantities reinjected, flared or vented are not included. The resulting products are referred to as "primary" products. Secondary production is the manufacture of energy products through the process of transformation of other fuels or energy, whether primary or secondary. The quantities of secondary fuels reported as production include quantities lost through venting and flaring during and after production. In this manner, the mass, energy and carbon within the primary source(s) from which the fuels are manufactured may be balanced against the secondary fuels produced. Fuels, electricity and heat produced are usually sold but may be partly or entirely consumed by the producer. 5.11. Imports of energy products comprise all fuel and other energy products entering the national territory. Goods simply being transported through a country (goods in transit) and goods temporarily admitted are excluded, while re-imports (i.e. domestic goods exported but subsequently readmitted) are included. The bunkering of fuel outside the reference territory by national merchant ships and civil aircraft engaged in international travel is also excluded from imports.[^39] Note that the country of origin of energy products should be recorded, where possible, as the country from which goods were imported, but not a transit country. 5.12. Exports of energy products comprise all fuel and other energy products leaving the national territory. Goods simply being transported through a country (goods in transit) and goods temporarily withdrawn are excluded, while re-exports (i.e. foreign goods exported in the same state as previously imported) are included. Also excluded are quantities of fuels delivered for use by merchant ships (including passenger ships) and civil aircraft of all nationalities during international transport of goods and passengers.[^40] Note that the country of destination of energy products (i.e. the country of the last known destination as it is known at the time of exportation) should be recorded as a country to which these products are exported to, but not a transit country. 5.13. It should be noted that the definitions of imports and exports used in energy statistics are those adopted by international merchandise trade statistics for a system of recording known as the general trade system, that is, all energy products entering and leaving the national territory of a country and which add to or are subtracted from the stock of material resources of a country are recorded as energy imports and exports,[^41] except for the bunkering of international fleet, which is excluded from trade figures.[^42] It should also be noted that, in energy balances, imports and exports exclude nuclear fuels as these are not within the scope of energy balances (see also chapter VIII). 5.14. International marine bunkers are quantities of fuels delivered to merchant ships (including passenger ships) of any nationality for consumption during international voyages transporting goods or passengers. International voyages take place when the ports of departure and arrival are in different national territories. Fuels delivered for consumption by ships during domestic transportation, fishing or military uses are not included here, but are considered part of final consumption of energy (see para. 5.94 for domestic navigation). For the purposes of energy statistics, international marine bunkers are not included in exports; they are recorded separately due to their importance, e.g. for the estimation of greenhouse gas emissions. 5.15. International aviation bunkers are quantities of fuels delivered to civil aircraft of any nationality for consumption during international flights transporting goods or passengers. International flights take place when the ports of departure and arrival are in different national territories. Fuels delivered for consumption by aircraft undertaking domestic or military flights are not included here, but are considered part of final consumption of energy (see para. 5.91 for domestic aviation). For the purposes of energy statistics, international aviation bunkers are not included in exports; they are recorded separately due to their importance, e.g. for the estimation of greenhouse gas emissions. 5.16. Stock changes. For the purposes of energy statistics, stocks are quantities of energy products that are held on the national territory and can be used to: (a) maintain service under conditions where supply and demand are variable in their timing or amount due to normal market fluctuations, or (b) supplement supply in the case of a supply disruption.[^43] Stocks used to manage a supply disruption may be called "strategic" or "emergency" stocks and are often held separately from stocks designed to meet normal market fluctuations, but both are considered here. Stock changes are defined as the increase (stock build) or decrease (stock draw) in the quantity of stocks over the reporting period and thus are calculated as a difference between the closing and opening stocks. 5.17. Transfers are essentially statistical devices to overcome practical classification and presentation issues resulting from changes in use or identity of a product. Transfers comprise products transferred and interproduct transfers. Products transferred refers to the reclassification (renaming) of products, which, for example, is necessary when finished oil products are used as feedstock in refineries. Interproduct transfers refer to the movements of fuels between product categories because of reclassification of a product that no longer meets its original specification. For example, aviation turbine fuel that has deteriorated or has been spoiled may be reclassified as heating kerosene. 5.18. Transformation is the process where part or all of the energy content of a product entering a process moves from this product to one or more different products leaving the process (e.g., from coking coal to coke, from crude oil to oil products, or from fuel oil to electricity) (see section D.2 for further discussion). 5.19. Losses refer to losses during the transmission, distribution and transport of fuels, heat and electricity. Losses also include venting and flaring of manufactured gases, losses of geothermal heat after production and pilferage of fuels or electricity. However, production of secondary gases includes quantities subsequently vented or flared. This ensures that a balance can be constructed between the use of the primary fuels from which the gases are derived and the production of the gases. 5.20. Energy industries own use refers to the consumption of fuels and energy for the direct support of the production and preparation for use of fuels and energy, except heat not sold. As such, it covers not only own use by energy industries as defined in para. 5.23, but also by other energy producers as defined in para. 5.75. Quantities of fuels transformed into other fuels or energy are not included here, but within transformation; neither are quantities used within parts of the energy industry not directly involved in the activities listed in the definition. These quantities are reported within final consumption. 5.21. Non-energy use consists of the use of energy products as raw materials for the manufacture of products outside the scope of SIEC, as well as for direct uses that do not involve using the products as a source of energy, nor as a transformation input. Examples are lubrication, sealing, preservation, road surfacing and use as a solvent.[^44] 5.22. Final consumption refers to all fuel and energy delivered to users for both their energy and non-energy uses, and which do not involve a transformation process as defined in para. 5.18. ## D. Energy industries 5.23. Definition of energy industries. Energy production is an energy flow of major importance. Data on energy production are required for various policy and analytical purposes; therefore, the provision of further details on energy production is one of the priorities of energy statistics. Energy can be produced by various economic units. However, not all of them should be treated as belonging to energy industries. In order to ensure international comparability, it is recommended that energy industries be defined as consisting of economic units whose principal activity[^45] is primary energy production, transformation of energy or distribution[^46] of energy. For practical reasons, a few additions are made, as described in para. 5.26. 5.24. Statistics on energy industries. To have a better understanding of the efforts of a country to extract, produce, transform and distribute energy products, it is recommended that the collection, compilation and dissemination of statistics describing the main characteristics and activities of energy industries be considered as part of official energy statistics. > **Box 5.1** > **Principal, secondary and ancillary activities** > > The principal activity of a producer unit is the activity whose value added exceeds that of any other activity carried out within the same unit (SNA 2008, para. 5.8). > > A secondary activity is an activity carried out within a single producer unit in addition to the principal activity and whose output, like that of the principal activity, must be suitable for delivery outside the producer unit. The value added of a secondary activity must be less than that of the principal activity, by definition of the latter (SNA 2008, para. 5.9). > > An ancillary activity is incidental to the main activity of an enterprise. It facilitates the efficient running of the enterprise but does not normally result in goods and services that can be marketed (SNA 2008, para. 5.10). 5.25. Energy industries are engaged in primary production, transformation and distribution of energy products. These activities are very diverse and their detailed technical descriptions quite complex. However, for the purposes of energy statistics, activities of economic units belonging to energy industries can be conveniently identified by the establishments (plants) in which they occur. For example, the typical representatives of primary production are coal mines and oil and gas extraction plants. 5.26. Activities of energy industries. In order to improve cross-country comparability of statistics on energy production by energy industries it is recommended that countries identify, as far as feasible and applicable, the energy industries listed in the left column of table 5.1. It is important to note that it considers a broader definition of energy industries than the core mentioned in para. 5.23, covering some plants, such as blast furnaces, for which the main activity is not energy-related. Table 5.1 also provides information on the ISIC Rev. 4 categories (division/group/class) where the different energy industries can be found. **Table 5.1 — Energy industries with reference to the relevant ISIC category** | Energy industry | ISIC Rev. 4 | | --- | --- | | Electricity, CHP and heat plants(a) | Division: 35—Electricity, gas, steam and air conditioning supply | | Pumped storage plants | | | Coal mines | Division: 05—Mining of coal and lignite | | Coke ovens | Group: 191—Manufacture of coke oven products | | Coal liquefaction plants | Group: 192—Manufacture of refined petroleum products | | Patent fuel plants | Group: 192—Manufacture of refined petroleum products | | Brown coal briquette plants | Group: 192—Manufacture of refined petroleum products | | Gas works(b) (and other conversion to gases) | Group: 352—Manufacture of gas; distribution of gaseous fuels through mains | | Gas separation plants | Division: 06—Extraction of crude petroleum and natural gas | | Gas-to-liquids (GTL) plants | Group: 192—Manufacture of refined petroleum products | | LNG plants/regasification plants | Group: 091—Support activities for petroleum and natural gas extraction; Class: 5221—Service activities incidental to land transportation | | Blast furnaces | Group: 241—Manufacture of basic iron and steel | | Oil and gas extraction | Division: 06—Extraction of crude petroleum and natural gas; Group: 091—Support activities for petroleum and natural gas extraction | | Oil refineries | Group: 192—Manufacture of refined petroleum products | | Charcoal plants(c) | Class: 2011—Manufacture of basic chemicals | | Biogas production plants(d) | Group: 352—Manufacture of gas; distribution of gaseous fuels through mains | | Nuclear fuel extraction and fuel processing | Class: 0721—Mining of uranium and thorium ores; Class: 2011—Manufacture of basic chemicals | | Other energy industry not elsewhere specified(e) | Class: 0892—Extraction of peat; …. | > **Notes to table 5.1:** > - (a) Also including the distribution of electricity and heat to consumers. > - (b) Also including the distribution of these gases. > - (c) The provided ISIC link refers to the production of charcoal through distillation of wood. If charcoal is produced in the forest using traditional methods, the activity would be classified in ISIC 0220 ("Logging"). > - (d) Plants having the production of biogases as their main activity would be classified in ISIC class 3520, as indicated in the table above. However, biogases may also be produced as by-products of other activities, such as those classified in ISIC 3700 ("Sewerage") and 3821 ("Treatment and disposal of non-hazardous waste"). > - (e) The given ISIC link provides an example, namely the extraction of peat, but is not exhaustive. 5.27. A brief description of the energy industries of table 5.1 is presented below. 5.28. Electricity, combined heat and power (CHP) and heat plants: see section 1 below for a detailed presentation of these activities. 5.29. Coal mines are plants extracting coal through underground or open-cast mining. In addition to the extraction activity itself, the operation of coal mines also includes operations such as grading, cleaning, compressing, etc., leading to a marketable product. 5.30. Coke ovens are large ovens within which coke oven coke, coke oven gas and coal tars are produced by high temperature carbonization of coking coal. 5.31. Coal liquefaction plants are plants where coal is used as a feedstock to produce liquid fuels by hydrogenation or carbonization. They are also known as coal to liquid (CTL) plants. 5.32. Patent fuel plants are plants manufacturing patent fuel. 5.33. Brown coal briquette plants are plants manufacturing brown coal briquettes (BKB). 5.34. Gas works (and other conversion to gases) are plants manufacturing gases for distribution to the public either directly or after blending with natural gas. Note that the gases are collectively referred to as "gas works gas and other manufactured gases for distribution"; short name—gas works gas. Some gas works may produce coke, as well as gas. 5.35. Gas separation plants are plants involved in the separation of associated gas from crude oil, and/or the separation of condensate, water, impurities and natural gas liquids from natural gas. In addition to the above, the activities of these plants may also involve fractionation of the recovered natural gas liquids. 5.36. Gas-to-liquids (GTL) plants are plants in which natural gas is used as a feedstock for the production of liquid fuels. The liquid fuels are usually used as vehicle fuels. Note that the GTL plants are quite different from liquefied natural gas (LNG) plants, which convert gaseous natural gas into liquid natural gas. 5.37. LNG plants/regasification plants are plants for carrying out liquefaction and/or regasification of natural gas for the purpose of transport. This activity can be carried out on or off the actual point of production. 5.38. Blast furnaces are furnaces that produce blast furnace gas as a by-product when making pig iron from iron ore. During the process, carbon, mainly in the form of coke, is added to the blast furnace to support and reduce the iron oxide charge and provide heat. Blast furnace gas comprises carbon monoxide and other gases formed during the heating and reduction process. 5.39. Oil and gas extraction are activities of extracting crude oil, mining and extracting oil from oil shale and oil sands, extracting natural gas and recovery of natural gas liquids. This includes overall activities of operating and/or developing oil and gas field properties, including such activities as drilling, completing and equipping wells, operating separators, emulsion breakers, desilting equipment and field gathering lines for crude petroleum and all other activities in the preparation of oil and gas up to the point of shipment from the producing site. 5.40. Oil refineries are plants that transform crude oil and other hydrocarbons (together with additives, feedstocks and natural gas liquids) into finished oil products. Typical finished products are liquefied petroleum gases, naphtha, motor gasoline, gas oils, aviation fuels and other kerosene, and fuel oils. 5.41. Charcoal plants are plants in which wood, or other vegetal matter is carbonized through slow pyrolysis to produce charcoal. 5.42. Biogas production plants are plants for capturing and/or manufacturing biogases. Biogases arise from the anaerobic fermentation of biomass. They can be derived from several sources, including landfills, sewage sludge and agricultural residues. They also include synthesis gas produced from biomass. 5.43. Nuclear fuel extraction and fuel processing plants are plants involved in the mining of ores chiefly valued for their uranium and thorium content, the concentration of such ores, the production of yellowcake, the enrichment of uranium and thorium ores, and/or the production of fuel elements for nuclear reactors. 5.44. Other energy industry not elsewhere specified. This is a residual category that refers to any energy industry not covered elsewhere in the list above. One example is the extraction of peat for energy purposes. ### 1. Electricity and heat 5.45. Statistics on electricity and heat (SIEC section 7 (Electricity) and section 8 (Heat)) are collected according to the type of producer and type of generating plant. Two types of producers are distinguished:[^47] - Main activity producers. These are units that produce electricity or heat as their principal activity. Formerly known as public utilities, these enterprises may be privately or publicly owned companies. - Autoproducers (electricity). These are units that produce electricity, but for which the production is not their principal activity. - Autoproducers (heat). These are units that produce heat for sale, but for which the production is not their principal activity. Deliveries of fuels for heat generated by a unit for its own purposes are classified as final consumption, and not as transformation inputs. 5.46. It should be noted that any own use by the autoproducer in support of the production of electricity and/or production of heat for sale should be reported under energy industries own use in the same way that the inputs to and the output of electricity and heat sold figure under transformation processes. Energy consumed in support of the principal economic activity should be reported under final consumption (or again in energy industries own use if the autoproducer happens to be an energy industry such as an oil refinery). 5.47. Three types of generating plants are also distinguished: - Electricity plants refer to plants producing only electricity. The electricity may be obtained directly from natural sources such as hydro, geothermal, wind, tidal, marine, solar energy or from fuel cells, or from the heat obtained from the combustion of fuels or nuclear reactions. - CHP plants refer to plants that produce both heat and electricity from at least one generating unit in the plant. They are sometimes referred to as "co-generation" plants. - Heat plants refer to plants (including heat pumps and electric boilers) designed to produce heat only for deliveries to third parties. Deliveries of fuels for heat generated by an autoproducer for its own purposes are classified as final consumption. 5.48. The different data reporting requirements for the production and use of fuels are summarised schematically in table 5.2. **Table 5.2 — Main activity producers and autoproducers of electricity and heat** | Type of producer | Electricity plant | CHP plant | Heat plant | | --- | --- | --- | --- | | Main activity producers | Report all production and all fuel used | Report all electricity and heat produced and all fuel used | Report all heat produced and all fuel used | | Autoproducer | | Report all electricity produced and heat sold with corresponding fuel used | Report heat sold and corresponding fuel used | > Source: IEA Electricity Questionnaire reporting instruction. 5.49. Note that pumped storage plants are plants where electricity is used during periods of lower demand to pump water into reservoirs for subsequent release and electricity generation during periods of higher demand. Less electricity is eventually produced than is consumed to pump the water into the higher reservoir. 5.50. The different types of technology/processes for the generation of electricity and heat are defined as follows. 5.51. Solar photovoltaics (PV) electricity refers to electricity produced from solar photovoltaics, i.e. by the direct conversion of solar radiation through photovoltaic processes in semiconductor devices (solar cells), including concentrating photovoltaic systems. 5.52. Solar thermal electricity refers to electricity produced from solar heat (both concentrating and non-concentrating, see para. 5.62). 5.53. Wind electricity refers to electricity produced from devices driven by wind. 5.54. Hydroelectricity refers to electricity produced from devices driven by fresh, flowing or falling water. 5.55. Wave electricity refers to electricity produced from devices driven by the motion of waves. 5.56. Tidal electricity refers to electricity generated from devices driven by tidal currents or the differences of water level caused by tides. 5.57. Other marine electricity refers to electricity generated from devices that exploit sources of marine energy not elsewhere specified. Examples of such sources are non-tidal currents, temperature differences and salinity gradients in seas or salinity differences between sea and fresh water. 5.58. Geothermal electricity refers to the electricity generated from the heat from geothermal sources. 5.59. Nuclear electricity refers to electricity generated by nuclear heat. 5.60. Electricity from chemical processes refers to electricity generated from heat recovered from a non-combusting chemical reaction. 5.61. Electricity from other sources refers to electricity produced from sources not elsewhere specified (including fuel cells). 5.62. Solar heat refers to the generation of heat from solar thermal (concentrating and non-concentrating). Heat from concentrating solar thermal refers to high temperature heat produced from solar radiation captured by concentrating solar thermal systems. The high-temperature heat can be transformed to generate electricity, drive chemical reactions, or be used directly in industrial processes. Heat from non-concentrating solar thermal refers to low-temperature heat produced from solar radiation captured by non-concentrating solar thermal systems. The heat can be used for applications, such as space heating, cooling, water heating, district heating and industrial processes. 5.63. Geothermal heat refers to heat extracted from the earth. The sources of the heat are radioactive decay in the crust and mantle and heat from the core of the earth. Heat from shallow geothermal sources includes heat gained by the earth through direct sunlight and rain. The heat is usually extracted from the earth in the form of heated water or steam. 5.64. Nuclear heat refers, for the purposes of energy statistics, to the heat obtained from a working fluid (possibly steam) in the nuclear reactor. A working fluid is the substance circulated in a closed system to convey heat from the source of heat to its point(s) of use. 5.65. Heat and/or electricity from combustible fuels refers to the production of heat and/or electricity from the combustion of fuels that are capable of igniting or burning, i.e. reacting with oxygen to produce a significant rise in temperature. 5.66. Heat from chemical processes refers to recovered heat generated in the chemical industry by exothermic reactions other than combustion, and used for steam-raising or other energy purposes. 5.67. Heat from other sources refers to heat from sources not elsewhere specified. ### 2. Transformation processes 5.68. Transformation processes play a vital role in the flow of energy throughout an economy, as they ensure that primary energy products that cannot be directly or effectively utilized are changed into other energy products more suitable for consumption. It is important to identify such processes in order to describe and analyse energy transformation more precisely and assess the resources necessary for carrying it out. In energy balances, energy transformation processes are reflected in the rows of the transformation block (see chapter VIII for more detail). 5.69. From the point of view of energy statistics, a transformation process is the movement of part or all of the energy content of a product entering the process to one or more different products leaving the process. There are two groups of transformation processes: (a) The physical or chemical conversion of a product into another product or products whose intrinsic properties differ from those of the original product. Examples are: - chemical or physical changes to the input product(s) resulting in the creation of products containing new chemical compounds (e.g., refining); - physical changes to the input product(s) resulting in a separation into several different products with intrinsic physical properties that are different from those of the input material (e.g., coke oven carbonization of coal); - conversion of heat into electricity; and - production of heat from combustion or electricity. (b) The aggregation or blending of products, sometimes involving a change of physical shape. Examples are: - blending of gases to meet safety and quality requirements before distribution to consumers; and - briquetting of peat and brown coal. 5.70. These transformation processes are currently identified by the plants in which they occur, namely: - Electricity plants - CHP plants - Heat plants - Coke ovens - Coal liquefaction plants - Patent fuel plants - Brown coal briquette plants - Gas works (and other conversion to gases) - GTL plants - Blast furnaces - Oil refineries - Charcoal plants - Peat briquette plants - Natural gas blending plants - Petrochemical plants - Other transformation processes not elsewhere classified 5.71. Most of these plants have already been described in the context of table 5.1. Descriptions of the remaining plants, which would appear under "Other energy industry not elsewhere specified" in table 5.1, are given below: 5.72. Peat briquette plants are plants manufacturing peat briquettes. 5.73. Natural gas blending plants are plants, separate from gas works, in which substitute natural gas (see gas works gas), petroleum gases or biogases are mixed with natural gas for distribution in the gas mains. Where blending of substitute natural gas with natural gas takes place within gas works, the blending is considered part of the gas works process. 5.74. Petrochemical plants are plants that convert hydrocarbon feedstock into organic chemicals, intermediate compounds and finished products, such as plastics, fibres, solvents and surfactants. Feedstock used by the plant is usually obtained from a refinery and includes naphtha, ethane, propane and middle distillate oils (for example, gas oil). The carbon and hydrogen in the feedstock are largely transferred to the basic chemicals and products subsequently made from them. However, certain byproducts are also created and returned to the refinery (such as pyrolysis gasoline), or burned for fuel to provide the heat and electricity required for cracking and other processes in the petrochemical plant. Note that since energy transformation is not the principal activity of petrochemical plants, they do not belong to energy industries and, as a group, are treated as energy consumers (see table 5.3). However, the energy transformation performed by these plants is reflected in the middle block of the energy balances (see chapter VIII). ## E. Other energy producers 5.75. Other energy producers are economic units (including households) that choose, or are forced by circumstance, to produce energy for their own consumption and/or to supply energy to other units, but for which energy production is not their principal activity. These units are engaged in the production, transformation and transmission/distribution of energy as a secondary and/or ancillary activity. This means that the "energy" output generated by these activities and measured in terms of value added does not exceed that of the principal activity of the unit. In the case of ancillary activities, the activities are carried out to support the principal and secondary activity of the unit. 5.76. Geographically remote industries may have no access to electricity unless they produce it themselves; iron and steel works requiring coke and the heat from it for their own production purposes will often produce their own coke and electricity. Sugar mills nearly always burn the bagasse they produce for generating steam, and process heat and electricity. An enterprise whose primary activity is the production of animal products (i.e., raising and breeding of pigs, sheep, etc.) could use its animal waste as fuel in a biogas system to generate electricity for its own use or to sell to a local market. Many industrial establishments and commercial organizations may have electricity-generating equipment that they can turn on in the event of failure in the public supply system (in which case they might even sell electricity to other consumers or to the public supply system). Households that use solar panels for generating electricity for their own use (and sometimes even for sale to third parties) are another example of other energy producers. 5.77. It is recognized that the collection of data on energy production by other energy producers might be challenging. However, it is recommended that countries, where such producers account for a significant part of total energy production, make efforts to obtain from them the detailed data and incorporate them in their official energy statistics, including in energy balances. The energy used in these processes should be recorded under transformation and energy industries own use (see para. 5.86 and 5.87).[^48] Countries where the production of energy by non-energy industries is small (as determined by the agency responsible for compilation and dissemination of official energy statistics) might limit their data collection from such industries to appropriate aggregates only or prepare estimates as necessary. ## F. Energy consumers and energy uses 5.78. Similar to information on energy producers, information on energy consumers is important for both energy policy and analytical purposes, as it allows for the formulation and monitoring of policies targeted, for example, to reinforcing and/or modifying consumption patterns. This section defines the major groups of energy consumers used in energy statistics and describes a cross classification between groups of users and types of uses. ### 1. Energy consumers 5.79. In energy statistics, energy consumers consist of economic units (enterprises and households) that act as final users of energy; they use energy products for energy purposes (heat raising, transportation and electrical services) and/or for non-energy purposes. It should be noted that the economic units belonging to the energy industries that use energy to produce other energy products are excluded from this group. Their energy use, by convention, is not part of the final consumption of energy and is considered separately as energy industries own use (see para. 5.20). 5.80. It is recommended that countries identify, as far as feasible and applicable, the groups of energy consumers as listed in table 5.3. To facilitate the collection of energy statistics and their integration with other economic statistics, table 5.3 also provides a correspondence between the identified groups of energy consumers and the relevant categories of ISIC Rev. 4. 5.81. The scope of each consumer group is defined by the scope of the economic units belonging to ISIC Rev. 4 categories in table 5.3, except for "households", which includes all households in their capacity as final consumers and not only those engaged in economic activities (as covered by ISIC).[^49] **Table 5.3 — Main categories of energy consumers** | Energy consumers | Correspondence to ISIC Rev. 4 | | --- | --- | | Manufacturing, construction and non-fuel mining industries | | | Iron and steel | ISIC Group 241 and Class 2431. Note that the consumption of energy products in coke ovens and blast furnaces is excluded, as these plants are considered part of the energy industries. | | Chemical and petrochemical | ISIC Divisions 20 and 21. Note that the consumption of energy products by plants manufacturing charcoal or carrying out the enrichment/production of nuclear fuels (both classified in ISIC 2011) is excluded, as these plants are considered part of the energy industries. | | Non-ferrous metals | ISIC Group 242 and Class 2432 | | Non-metallic minerals | ISIC Division 23 | | Transport equipment | ISIC Divisions 29 and 30 | | Machinery | ISIC Divisions 25, 26, 27 and 28 | | Mining and quarrying | ISIC Divisions 07 and 08, and Group 099, excluding the mining of uranium and thorium ores (Class 0721) and the extraction of peat (Class 0892). | | Food and tobacco | ISIC Divisions 10, 11 and 12 | | Paper, pulp and print | ISIC Divisions 17 and 18 | | Wood and wood products (other than pulp and paper) | ISIC Division 16 | | Textile and leather | ISIC Divisions 13, 14 and 15 | | Construction | ISIC Divisions 41, 42 and 43 | | Industries not elsewhere specified | ISIC Divisions 22, 31 and 32 | | Household | ISIC Divisions 97 and 98 | | Commerce and public services | ISIC Divisions 33, 36–39, 45–96 and 99, excluding ISIC 8422 | | Agriculture, forestry | ISIC Divisions 01 and 02 | | Fishing | ISIC Division 03 | | Not elsewhere specified (including defence activities) | ISIC Class 8422 | 5.82. It should be noted that the consumption of energy by defence activities (ISIC 8422) is recorded in the balance as "not elsewhere specified", as it includes all defence consumption of energy products, including for transport, bunkering, etc. (see also chapter VIII on energy balances). ### 2. Cross-classification of uses and users of energy 5.83. Energy products can be used for three purposes: (i) energy purposes; (ii) non-energy purposes; and (iii) transformation. The use of energy products for energy purposes is further broken down into two categories: for any energy purposes excluding transportation; and transportation purposes. In basic energy statistics and energy balances, data on the use of energy are presented by cross-classifying them by purpose and user groups (various categories of energy industries and energy consumers) as presented in table 5.1 and table 5.3, respectively. 5.84. An illustration of this cross-classification is presented in matrix form in figure 5.2, which shows the various uses of energy by purpose (by column) and the different users, i.e. energy industries and energy consumers (by row). Each cell, defined by the intersection of columns and rows, represents the use of energy products for specific purposes by a specific user. > **Figure 5.2 — Cross classification of uses and users of energy** > > | Users \ Uses | Transformation | Energy industries own use | Energy use (excluding for transport) | Energy use for transport | Non-energy use | > | --- | --- | --- | --- | --- | --- | > | Energy industries (Electricity and heat, Coal mines, Coke ovens, …) | (a) | Not applicable | Not applicable | (d) | (e) | > | Energy consumers (Iron and steel, …, Construction, …, Household, …) | (a) | (b) | (c) | (d) | (e) | > > 5.85. The matrix presented in the above figure can be used to illustrate important earlier-defined concepts. 5.86. Transformation is represented in figure 5.2 by box (a), which goes across all economic units within the territory of reference to take into account not only the transformation that occurs in energy industries but also the transformation that might occur as a secondary and/or ancillary activity by energy consumers. Statistics on transformation are disaggregated and presented according to the list in para. 5.70. When the transformation takes place outside the energy industries (i.e., by other energy producers) the energy consumed in the transformation is recorded under the most relevant category of the disaggregation, i.e. the most similar energy industry. 5.87. Energy industries own use is represented by box (b). As explained earlier in the text, it does not cover the use of energy products for transport or non-energy purposes by the energy industries. On the other hand, it also covers own use in energy production by other energy producers, i.e. economic units that produce energy products but are not part of the energy industries based on their principal activity. 5.88. Final energy consumption refers to all fuel and energy delivered to users for their energy use. This is represented in figure 5.2 as follows: (i) The use of energy products for energy purposes (excluding for transportation) by energy consumers—box (c); and (ii) The use of energy for transport by all economic units—box (d). #### Transport 5.89. Use of energy products for transportation purposes, box (d), is defined as the consumption of fuels and electricity used to transport goods or persons between points of departure and destination within the national territory irrespective of the economic sector within which the activity occurs. The classification of the consumption of fuels by merchant ships and civil aircraft undertaking the transport of goods or persons to another national territory is covered under the definitions for international marine and aviation bunkers and is therefore excluded from this definition. However, deliveries of fuels to road vehicles going beyond national borders cannot be readily identified and by default are included here. 5.90. Transport can be disaggregated by mode of transport as indicated in table 5.4 below: **Table 5.4 — Mode of transport** | Transport | | --- | | Road | | Rail | | Domestic aviation | | Domestic navigation | | Pipeline transport | | Transport not elsewhere specified | 5.91. Domestic aviation refers to quantities of aviation fuels delivered to all civil aircraft undertaking a domestic flight transporting passengers or goods, or for purposes such as crop-spraying and the bench-testing of aero engines. A domestic flight takes place when the departure and landing airports are on national territory. In cases where distant islands form part of the national territory, requiring long flights through the air space of other countries, those flights are, nevertheless, considered part of domestic aviation. Military use of aviation fuels should not be included in domestic aviation but under the energy balance item "not elsewhere specified". The use of fuel by airport authorities for ground transport within airports is also excluded here, but included under "commerce and public services". 5.92. Road refers to fuels and electricity delivered to vehicles using public roads. Fuels delivered for "off-road" use and stationary engines should be excluded. Off-road use comprises vehicles and mobile equipment used primarily on commercial industrial sites or private land, or in agriculture or forestry. The deliveries of fuels related to these uses are included under the appropriate final consumption heading. Deliveries for military uses are also excluded here but included under "not elsewhere specified". The fuel use for freight transport by road and by trolley buses is included here. 5.93. Rail refers to fuels and electricity delivered for use in rail vehicles, including industrial railways. This includes urban rail transport (including trams). 5.94. Domestic navigation refers to fuels delivered to vessels transporting goods or people and undertaking a domestic voyage. A domestic voyage is between ports of departure and destination in the same national territory without intermediate ports of call in foreign ports. Note that this may include journeys of considerable length between two ports in a country (e.g., San Francisco to Honolulu). Fuels delivered to fishing vessels are excluded here but included under "fishing". 5.95. Pipeline transport refers to fuels and electricity used in the support and operation of pipelines transporting gases, liquids, slurries and other commodities between points within the national territory. It comprises the consumption at pumping stations and for the maintenance of the pipeline. Consumption for maintaining the flow in pipelines carrying natural gas, manufactured gas, hot water and steam in distribution networks is excluded here, but included under the appropriate heading within "energy industries own use". Consumption for the transport of natural gas in transmission networks is included. Consumption of fuels or electricity for maintaining the flow in pipelines carrying water is included in "commerce and public services". A transmission pipeline transports its contents to distribution pipelines for eventual delivery to consumers. Transmission pipelines for gas usually operate at pressures considerably higher than those used in distribution pipelines. 5.96. Transport not elsewhere specified refers to deliveries of fuels or electricity used for transport activities not covered within the modes of transport defined elsewhere. Most of the forms of transport listed in ISIC Class 4922 (other land transport) are included in the modes of transport defined elsewhere. However, consumption of electricity for téléphériques (telfers), and ski and cable lifts would be included here. 5.97. Non-energy use of energy products is represented in figure 5.2 by box (e) and covers the use of energy products for non-energy purposes, irrespective of the economic activity where the use takes place (energy consumers or energy industries). This use is usually presented in an aggregated form and thus not linked to any specific economic activity (see also chapter VIII). --- [^38]: It is acknowledged that there are additional energy flows that are relevant for the compilation of energy accounts such as, for example, the use of energy products abroad by resident units and the use of energy products inland by non-resident units. [^39]: Such fuels should be classified as "international marine bunkers" or "international aviation bunkers", respectively, in the country where such bunkering is carried out (see paras. 5.14, 5.15). [^40]: These quantities are recorded as "international marine bunkers" and "aviation bunkers", respectively. [^41]: See International Merchandise Trade Statistics: Concepts and Definitions 2010, United Nations (2010). [^42]: These definitions differ from those used in the national accounts where exports and imports are defined as transactions between residents and non-residents. Therefore, compilers of energy accounts should make necessary adjustments to basic energy statistics before using them. [^43]: The notion of stocks dealt with in this chapter corresponds to what in economic statistics and national accounts is referred to as inventories. [^44]: Some studies of the non-energy use of fuels also classify the use of reductants as non-energy use; however, in energy statistics the use of reductants (mostly for the manufacture of iron and steel) is considered as use for energy purposes, because the gases created by the reduction process, which contain most of the carbon from the reductant, are used as fuels to sustain the process or for other heat raising purposes. Reductants are carbon from fuels (usually cokes) that are heated with metal oxides. During the process, the formation of carbon monoxide removes the oxygen from the metal oxides and produces the pure metal. [^45]: For a more detailed definition of principal activity see box 5.1. [^46]: Note that distribution here refers to distribution systems (consisting, for example, of lines, meters, wiring and pipes) that convey energy products received from the generation facility or the transmission system to the final consumer, and not the "transmission systems" that convey the energy products from the generation facility to the distribution system. Distribution here also excludes the wholesale of energy products (for example, bottled gases). [^47]: The definitions refer to "units", which in practice will often be chosen as establishments but could also refer to enterprises or households, depending on circumstances and data availability. [^48]: This is similar to treating these secondary and ancillary activities related to energy as performed by a separate unit for collection purposes, while maintaining the definition of autoproducers in para. 5.45. [^49]: ISIC Divisions 97 and 98 only cover households engaged in economic activities (as employers or as producers of undifferentiated goods or services for own use).