=== ires-2018-page-084.pdf === 71 Chapter VI Statistical units and data items A. Introduction 6.1. The aim of this chapter is to describe entities about which information is sought and for which energy statistics are ultimately compiled (i.e. statistical units), and to provide a reference list of data items to be collected from those entities in order to assist countries in the organization of their data collection activities and ensure maximum possible comparability of the collected data with other economic statistics. The clear identification of the statistical units and their consistent use is a fundamental precondition for obtaining unduplicated and comparable data about any phenomenon under investigation, including energy. 6.2. It should be noted that the definitions of most of the data items are determined by the definitions of the relevant energy products (see chapter III) and flows (see chapter V), and are not reproduced in this chapter. However, if certain data items are not covered in chapters III and V, or need further elaboration, additional explanations are provided. 6.3. The list of data items presented in this chapter represents a reference list in the sense that it contains all generally desirable data items for the compilation and dissemination of energy statistics as part of official statistics. It is recommended that countries use the reference list of data items for selecting data items for use in their national energy statistics programmes, in accordance with their own circumstances, respondent load and available resources. It is further recommended that the data items be selected in a way to allow for an adequate assessment of the country’s energy situation, reflect main energy flows specific to the country and enable, as a minimum, the compilation of energy balances in an aggregated format. It is recognized that the compilation of energy statistics is a complex process and involves both direct data collection by energy statisticians, and the re-use of data collected via other national statistics, such as enterprise, foreign trade and price statistics, household statistics, and data from administrative sources. The agency responsible for the overall official energy statistics programme should be aware of the advantages and shortcomings of these other statistics and make efforts to assemble the various data into a coherent data set that best match the expectations of users. B. Statistical units 1. Statistical units and their definitions 6.4. A statistical unit is an entity about which information is sought and for which statistics are ultimately compiled. It is also the unit at the basis of statistical aggregates and to which tabulated data refer. Because of the diversity of economic entities involved in the production, distribution and consumption of energy, energy data compilers should be aware of the different types of statistical units in order to organize data collection, as well as to ensure that data are interpreted and used correctly in conjunction with other statistics. The universe of economic entities involved in the production, transformation and consumption of energy is  === ires-2018-page-085.pdf === 72 50 International Recommendations for Energy Statistics (IRES) For a detailed description of statistical units and their characteristics, see the DESA/UNSD paper “Statistical Units” (ESA/ STAT/2008/6), available from https://unstats.un.org/unsd /isdts/docs/StatisticalUnits.pdf. vast. It varies from small local energy producers or distributors to large and complex corporations engaged in many different activities carried out at or from many geographical locations. These entities vary in their legal, accounting, organizational and operating structures, and have different abilities to report data. The concepts of statistical units and their characteristics briefly introduced below are intended to assist energy statistics compilers to better organize their work.50 6.5. Statistical units can be divided into two categories: (a) Observation units—identifiable legal/organizational or physical units which are able, actually or potentially, to report data about their activities; and (b) Analytical units—units created by statisticians, often by splitting or combining observation units, in order to compile more detailed and homogeneous statistics than is possible by using data on observation units. Although analytical units are not able to report data themselves about their activities, indirect methods of statistical estimation and imputation of such data exist. The use of analytical units varies from country to country. It should be noted, however, that the accuracy of energy statistics may be increased through the use of analytical units in cases where complex economic entities are active in both energy production and other economic activities. In this connection, countries are encouraged to use analytical units as necessary and feasible in order to improve the quality of their energy statistics. Data about activities of statistical units can be collected from those units themselves (i.e., through census or surveys) or from others (i.e., administrative sources) (see chapter VII on data collection and compilation for details). 6.6. For practical purposes of collecting energy statistics, the following statistical units are differentiated and defined below: enterprise, establishment, kind-of-activity unit, unit of homogeneous production and household. 6.7. Enterprise. An economic entity in its capacity as a producer of goods and services is considered to be an enterprise if it is capable, in its own right, of owning assets, incurring liabilities and engaging in economic activities and transactions with other economic entities. It is also an economic transactor with autonomy in respect of financial and investment decision-making, and with the authority and responsibility for allocating resources for the production of goods and services. It may be engaged in one or more productive activities at one or more locations. 51 In energy statistics, the term plant is often used as an equivalent of the term establishment. 6.8. Establishment. An establishment is defined as an enterprise or part of an enterprise that is situated in a single location, and in which only a single productive activity is carried out, or in which the principal productive activity accounts for most of the value added. 51 Although the definition of an establishment allows for one or more secondary activities to be carried out, their magnitude should be small compared with that of the principal activity. If a secondary activity is as important, or nearly as important, as the principal activity, then the unit is more like a local unit, that is, an enterprise (or part of an enterprise) which engages in productive activities at or from one location. 6.9. In the case of most small- and medium-sized businesses, the enterprise and the establishment will be identical. In general, it is recommended that large enterprises engaged in many economic activities that belong to different industries be broken up into one or more establishments, provided that smaller and more homogeneous units can be identified for which data on energy production or other activities attributed to energy industries may be meaningfully compiled. 6.10. Kind-of-activity unit (KAU). Any given enterprise may perform many different activities, both related and not related to energy. To focus on the part of the enterprise that is of interest to energy statistics, an analytical statistical unit, called the kind-of-activity unit (KAU), may be constructed and used by the energy data compiler. A KAU is defined as an  === ires-2018-page-086.pdf === 73 Statistical units and data items enterprise or part of an enterprise that engages in only one kind of productive activity or in which the principal productive activity accounts for most of the value added. There is no restriction placed on the geographical area in which the activity is carried out. Therefore, if there is only one location from which an enterprise carries out that activity, the KAU and the establishment are the same units. 6.11. Unit of homogeneous production. To ensure the most complete coverage, energy statistics compilers may need, in certain cases, to use an even more detailed splitting of the enterprise activities. The statistical unit appropriate for such a purpose is the unit of homogeneous production. It is defined as a production unit in which only a single (non-ancillary) productive activity is carried out. For example, if an enterprise is engaged primarily in non‑energy-related activities, but still produces some energy, the compiler may “construct” an energy-producing unit, which might be classified under the proper energy activity category and collect (or estimate) data about its energy production and inputs used in such a production (while maintaining the autoproducer definition of para. 5.45 if the unit is an electricity or heat producer). This is the case, for example, of the sugar industry, which burns bagasse to generate electricity for own use. While it may not be possible to collect data corresponding to such a unit directly from the enterprise or establishment, in practice, such data are calculated/ estimated by transforming the data supplied by establishments or enterprises on the basis of various assumptions or hypotheses. 6.12. Households. The scope of energy statistics also includes statistics (mainly on consumption) in the household sector. In data collection from this sector, a special statistical unit— household—is used. A household is defined as a group of persons who share the same living accommodation, who pool some or all of their income and wealth, and who consume certain types of goods and services collectively, mainly housing and food. In general, each member of a household should have some claim upon the collective resources of the household. At least some decisions affecting consumption or other economic activities must be taken for the household as a whole.52 In some cases, a household may also produce energy products for sale or for own use. 2. An illustrative example 6.13. In order to illustrate the different types of statistical units, an imaginary, but realistic example is presented below. Figure 6.1 shows a schematic representation of a large corporation involved in the primary production, transformation and distribution of energy. The corporation consists of four separate companies (identified in the figure as company A, B, C and D) which carry out activities of extraction, transportation, refining and sale of oil products. Each tile in the figure represents a different geographical location. In each tile a description of the kind of economic activity(ies) carried out at that location is described. For easy reference, the tiles are numbered (1) to (8). 6.14. Company A is engaged in the activity of crude oil extraction (ISIC Rev.4, Group 061). It has plants at two different locations illustrated in the figure by tiles (1) and (2). The crude oil is then transported through pipelines by company B (ISIC Rev. 4, Group 493). Although the pipelines themselves are geographically distributed, the centre of operation can be assigned to a physical location and is illustrated by tile (3). Company B transports the crude oil to Company C, which operates three separate refineries located in different geographical areas, illustrated by tiles (4), (5) and (6). The refinery associated with tile (6) also has a minor secondary activity of electricity generation (ISIC Rev. 4, Group 351), from which small quantities of electricity are sold to third parties. 52 SNA 2008, para. 4.149.  === ires-2018-page-087.pdf === 74 International Recommendations for Energy Statistics (IRES) Figure 6.1 Example of a large oil corporation 6.15. Company C provides some of its refined oil products (i.e., motor gasoline, diesel, etc.) to Company D, whose principal activity is the retail sale of motor gasoline and diesel (ISIC Rev. 4, Group 473) at the gasoline stations illustrated by tiles (7) and (8) in the figure. The gasoline station at tile (8) also carries out retail sale of food, beverages, tobacco and miscellaneous household equipment as a significant secondary activity (ISIC Rev. 4 Group 471). 6.16. It should be noted that simply looking at the location and type of activity is not sufficient to determine which of these units can be considered an enterprise, since an enterprise has to fulfil additional criteria (see para. 6.7), including the capability of incurring liabilities and autonomy in respect of financial transactions. For the purpose of this example, companies A, B, C and D are assumed to individually fulfil these criteria and constitute four separate enterprises, while the units represented by tiles do not (except for tile (3)). 6.17. Each of the installations in tiles (1) to (7) can then be considered to be an establishment, since they are all situated in a single location and do not carry out secondary activities of any significant magnitude. The gas station illustrated by tile (8) has a significant secondary activity of other retail. If the magnitude of this activity is as important, or nearly as important as that of its primary activity, this gas station could, for statistical purposes, be split into two separate establishments. 6.18. Since the definition of a KAU does not depend on physical location, but considers only productive activity, the installations at tiles (1) and (2) can collectively be considered one KAU. Installation (3) can be considered a separate KAU. The same can be said for the installations at tiles (4), (5) and (6) taken together. Whether or not the installations in (7) and (8) can be considered together as a single KAU depends on the significance of the secondary activity in (8). If this activity is important, it will have to be separated as a second KAU located in (8), similar to the theoretical split mentioned in para. 6.17.  === ires-2018-page-088.pdf === Statistical units and data items 6.19. If the unit of homogeneous production (UHP) is considered for describing the example, the installations at tiles (1) and (2) could be collectively considered a UHP, but not the installations at tiles (4), (5) and (6), since the installation at (6) is also engaged in some electricity production. In order to define units of homogeneous production, the installation at this tile needs to be conceptually split into two parts: one for the refinery operation and another for the generation of electricity. The installations at (4) and (5), together with the refinery part of the installation at (6) can collectively be considered a unit of homogeneous production, and the electricity generating component of (6) can be considered as a separate unit (of homogeneous production). A similar treatment has to be applied to tiles (7) and (8). 6.20. While the last two paragraphs illustrate a general approach, this is not recommended in the case of energy statistics (see para. 6.21). The use of the UHP can be justified in certain cases (see para. 6.11) but is usually not applied to the whole range of units covered by the statistics collected. The use of enterprise, establishment, KAU or UHP may lead to different results (e.g. when broken down by economic activity) and deviations from the recommendation in para. 6.21 should be carefully weighed. 3. Statistical units for energy statistics 6.21. For the inquiries dealt with in the current recommendations, the statistical units should ideally be the establishment and households. The establishment is recommended because it is the most detailed unit for which the range of data required is normally available. For many analytical applications, data need to be grouped according to such characteristics as kind-of-activity, geographical area and size, and this is facilitated by the use of the establishment unit. 6.22. However, the choice of statistical unit will also be guided by the purpose of the data collection, user needs and the availability of data. Therefore, the enterprise could also be used as the statistical unit. In practice, in the majority of the cases, especially for smaller units, the establishment and the enterprise are the same units. C. Reference list of data items 6.23. This section provides the reference list of data items for use in national energy statistics, aiming to satisfy basic needs of energy policy makers, the business community and the general public, and to ensure the international comparability of such statistics. The list consists of five parts: (i) data items on the characteristics of statistical units; (ii) data items on energy stocks and flows; (iii) data items on production and storage capacity; (iv) data items for assessment of the economic performance of the energy industries; and (v) data items on mineral and energy resources. 1. Characteristics of statistical units 6.24. Data items on characteristics of statistical units are used for the unique identification of units, their classification within particular activity groups and for the description of various aspects of their structure, operation and relationship with other units. Information about these characteristics of the statistical units allows for the compilation of statistics on the size of energy industries as a whole, as well as on their economic and geographical structure. Also, it is a precondition for an effective organization of statistical sample surveys, as well as for making comparisons and establishing linkages between energy data from different sources, thus significantly reducing the duplication in data collection and the response burden. 75  === ires-2018-page-089.pdf === 76 International Recommendations for Energy Statistics (IRES) 6.25. The main characteristics of the statistical unit are: its identification code, location, kind of activity, period of operation, type of economic organization, type of legal organization and ownership, and size. 53 Such a code may comprise digits identifying its geographical location, kind of activity, whether a unit is a principal producing unit or an ancillary unit, and link to its subsidiaries/principal if any, etc., although such practice is not always recommended. Item Number Data item 0.1 Identification code 0.2 Location 0.3 Kind of activity 0.4 Period of operation 0.5 Type of economic organization 0.6 Type of legal organization and ownership 0.7 Size 6.26. Identification code. The identification code is a unique number assigned to a statistical unit.53 The unique identification of statistical units is necessary in order to: (i) allow their registration in statistical business registers; (ii) permit the collection of information about them via administrative sources; (iii) provide a sampling base for statistical surveys; and (iv) permit demographic analysis of the population of units. The identification code must not change throughout the life of the unit, although some of the units’ other characteristics may change. Common identification codes shared with administrative authorities and other government departments greatly facilitate the statistical work, including the connection of the statistical business register, if such is established, with other registers. 6.27. Location. The location is defined as the place at which the unit is physically performing its activities, not the location of its mailing address. This characteristic serves two important purposes. First, to identify the units and classify them by geographical regions at the most detailed level as demanded by the statistical programme, and second, if a unit operates in more than one location, to allocate its economic activity to the location where it actually takes place. The latter is important for sub-national analyses. Since the classification of units by location is of particular national interest, any geographical classification should aim to distinguish sub-national levels (i.e., economic regions or administrative divisions, states or provinces, local areas or towns). 6.28. The details about mailing address, telephone and fax numbers, email address and contact person are also important identification variables, since these details are used for mailing the statistical questionnaires, written communication with the unit or making ad hoc queries about its activity. Up-to-date information about any changes in those variables is crucial for the efficient work of statistical authorities. 6.29. Where an enterprise has more than one establishment, it may or may not have one location and address. Often, the enterprise address is used for administrative purposes and the establishment addresses for statistical purposes. There is, however, a need for care when dealing with large complex enterprises. A multi-establishment enterprise should be requested to provide location details about each of its establishments, or the establishment may be asked to provide the name and location of the enterprise that owns it so that a data set in the register on the enterprise and its component establishments can be established. In some cases, it may be necessary to correspond with both the establishment and the enterprise if, for instance, the unit supplying employment details is different from the one providing financial details. 6.30. Kind of activity. The kind of activity is the type of production in which a unit is engaged and should be determined in terms of the national activity classification which, in turn, is recommended to be based on the latest version of the International Standard Industrial Classification of All Economic Activities (ISIC Rev. 4) or be correlated with it.  === ires-2018-page-090.pdf === Statistical units and data items 6.31. Period of operation. This indicates the period the establishment has been in operation during the reference period. It would be useful to seek information for the following items: (a) in operation since (date)—important, for instance, for the determination of electricity installed capacity as of a determined date; (b) temporary or seasonal inactivity—useful, for example, to track refinery shut-downs that might explain a decrease in annual refinery throughput/output; (c) ceased operation (date)—also important for determining installed capacity; and (d) sold or leased to another operator (name of new operator), which might explain changes in electricity capacity/production between main and autoproducers. Besides the information that this characteristic provides about the activity status of the unit (active or temporarily inactive), it also helps in interpreting the returns made by statistical units affected by seasonal factors and those made by statistical units that began or ceased operations during the reference period. Most of such information lies on the level of metadata and is useful for data quality checks. 6.32. Type of economic organization. The enterprise and the establishment are the main units used by countries for conducting industrial surveys. The characteristic “type of economic organization” is intended to indicate whether the establishment is the sole establishment of the enterprise of immediate ownership or part of a multi-establishment enterprise. If further details are required on this aspect of the industrial structure, the multi-establishment enterprises might be divided into classes according to the number of their constituent establishments or by the criteria used for classifying establishments (employment, value added) that are most appropriate for each country. 6.33. For the purpose of accurate measurement of energy production and other energy flows and for the compilation of various energy indicators, it is desirable to have the links between individual establishments and their parent enterprise clearly defined. More importantly, these links are fundamental for efficient sampling design and merging data obtained from different surveys covering both energy data and other variables needed to obtain indicators of energy industries’ performance. 6.34. Type of legal organization and type of ownership. The kind of legal organization is another important characteristic and possible criterion for the stratification of economic entities in statistical surveys. The type of legal organization is the legal form of the economic entity that owns the unit. The minimum classification of units by type of legal organization distinguishes between two main types, namely, incorporated units and unincorporated units. Incorporated units are legal entities separate from their owners and include corporations, as well as other incorporated entities such as cooperatives, limited liability partnerships and non-profit institutions. Unincorporated units are not incorporated as legal entities separately from their owners and may include public agencies that are part of the general government and sole proprietorships and partnerships owned by households. 6.35. In addition to the kind of legal organization, the main types of ownership, namely, private ownership and the various forms of public ownership of units, are useful optional characteristics. The criterion for distinguishing between privately and publicly owned units should be based on whether the ownership of the enterprise to which the establishment belongs rests with public authorities or private parties. Public units are those units owned or controlled by government units, whereas privately owned units are those owned or controlled by private parties. Public authorities or private parties are considered to be the owners of a given enterprise if they own all, or a majority of the unit’s shares, or its other forms of capital participation. Control over a unit consists of the ability to determine the unit’s policy by choosing appropriate directors, if necessary. 6.36. The category of publicly owned units can undergo further disaggregation into the main divisions of public ownership existing in each country, which would normally differentiate among central government ownership, ownership by state or provincial governments 77  === ires-2018-page-091.pdf === 78 54 International Recommendations for Energy Statistics (IRES) Further details on the type of legal organization and type of ownership are found in the International Recommendations for Industrial Statistics (UN 2009b). and ownership by local authorities. Within the group of privately owned units, a further classification of ownership, which differentiates between nationally owned units and those under foreign control, could be applied.54 6.37. Size. The size of a unit is an important data item for use in sample frame stratification and grossing up techniques. In general, the size classes of statistical units can be defined in terms of employment, turnover or other variables. In energy statistics, it might be necessary to define two size measures depending on the main objective of the analysis (e.g., in order to study the production/generation of energy, it may be more appropriate to define the size of an establishment in terms of the maximum capacity to generate energy products). This, however, may not be applicable to all energy products. To study the consumption of energy products, it may be more appropriate to measure the size of a unit by employment (for establishments) and number of persons (for households). 2. Data items on energy flows and stock levels 6.38. Data items presented in this section relate to the collection of statistics in physical units on energy flows, such as production, transformation and consumption, as well as on stock levels of different energy products. Such data items are designed to produce consistent time series that show changes in the supply and demand for various energy products. They also provide the basis for making comparisons and analysing the interrelationships between various energy products, and, when the data items are expressed in common units, make possible the regular monitoring of national energy patterns and the preparation of energy balances. 6.39. The data items in this section are presented in two sub-categories, namely: (i) data items common for all energy products, and (ii) data items applicable to a specific energy product. These data items are both required for the collection and dissemination of statistics on stocks and flows. Recommendations on units of measurement are provided in chapter IV. Data items common for all energy products 6.40. For each product identified in SIEC, the following data items can be compiled as applicable (see chapter V for the definitions of the relevant energy flows and related concepts). a b c d It is acknowledged that acquiring precise information on origin of imports and destination of exports is not always easy. The transformation processes are described in chapter V. Depending on the statistical unit, energy use (excluding transport) corresponds to energy industries own use if the statistical unit is an energy industry (table 5.1)— or final energy consumption if the unit is an energy consumer (table 5.3). The breakdown of transport is provided in table 5.4. Item number Data item 1.1 Production 1.2 Total imports 1.2.1 Imports by origina 1.3 Total exports 1.3.1 Exports by destinationa 1.4 International marine bunkers 1.5 International aviation bunkers 1.6 Stocks at the end of the period 1.7 Stock changes 1.8 Transfers 1.9 Transformation (by transformation processes)b 1.10 Losses 1.11 Energy usec 1.11.1 1.12 of which: for transport (by type of transport)d Non-energy use  === ires-2018-page-092.pdf === 79 Statistical units and data items Data items applicable to a specific group of energy products Coal and Peat 6.41. For products classified in SIEC under section 0 (Coal) and section 1 (Peat), the following list of additional data items applies. Item number Data item 2.1 Production 2.1.1 of which: underground 2.1.2 of which: surface 2.2 Production from other sources 6.42. Underground production refers to production from underground mines where coal is produced by tunnelling into the earth to the coal bed, and then mined with underground mining equipment such as cutting machines and continuous, longwall or shortwall mining machines. 6.43. Surface production refers to production from surface mines, that is from coal-producing mines where earth above or around the coal (overburden) is removed to expose the coal bed, which is then mined with surface excavation equipment such as draglines, power shovels, bulldozers, loaders and augers. These mines may also be known as area, contour, open-pit, strip or auger mines. 6.44. Production from other sources consists of two components: (a) recovered slurries, middlings and other low-grade coal products, which cannot be classified according to type of coal and include coal recovered from waste piles and other waste receptacles; and (b) fuels whose production is covered in other sections of SIEC, for example, from oil products (e.g. petroleum coke addition to coking coal for coke ovens), natural gas (e.g., natural gas addition to gas works gas for direct final consumption), biofuel and waste (e.g., industrial waste as binding agent in the manufacturing of patent fuel). Natural gas 6.45. For products classified in SIEC under section 3 (Natural Gas), the following list of additional data items applies. Item number Data item 3.1 Production 3.1.1 of which: associated gas 3.1.2 of which: non-associated gas 3.1.3 of which: colliery and coal seam gas 3.2 Production from other sources 3.3 Extraction lossesa 3.3.1 of which: gas flared 3.3.2 of which: gas vented 3.3.3 of which: gas re-injected 3.4 Gas flared (except during extraction) 3.5 Gas vented (except during extraction) 6.46. The production of natural gas refers to the dry marketable production within national boundaries, including offshore production. Production is measured after purification and a These are losses that occur during the extraction of natural gas and are not included under the production of natural gas. See para. 5.10 for the definition of production.  === ires-2018-page-093.pdf === 80 International Recommendations for Energy Statistics (IRES) extraction of natural gas liquids (NGLs) and sulphur. Extraction losses and quantities reinjected, vented or flared are not included in the figures for primary production (see para. 5.10). Production includes quantities used within the natural gas industry; in gas extraction, pipeline systems and processing plants. Production is disaggregated for the following: Associated gas: natural gas produced in association with crude oil; Non-associated gas: natural gas originating from fields producing hydrocarbons only in gaseous form; Colliery and coal seam gas: methane produced at coal mines or from coal seams, piped to the surface and consumed at collieries or transmitted by pipeline to consumers. 6.47. Production from other sources refers to the production of gas from energy products that have been already accounted for in the production of other energy products. Examples are the blending of petroleum gases, manufactured gases or biogases with natural gas. 6.48. Extraction losses refer to the losses that take place during extraction and are not included in the production of natural gas. In particular, they refer to: Gas flared: natural gas disposed of by burning in flares, usually at production sites or at gas processing plants. Gas vented: natural gas released into the air at the production site or at processing plants. Gas reinjected: the reinjection of natural gas into an oil reservoir in an attempt to increase oil recovery. 6.49. Flaring and venting, however, can also take place after the production of natural gas, for example, in the manufacture and transformation of certain gases. In this case, the gas flared and vented should also be separately reported. These quantities would be implicitly included in the data item for losses. Oil 6.50. For products classified in SIEC, under section 4 (Oil), the following list of additional data items applies. Item number Data item 4.1 Backflows from petrochemical industry to refineries 4.2 Refinery intake (by products) 4.3 Refinery losses 4.4 Direct use (of crude oil, NGL, etc.) 6.51. Backflows from petrochemical industry to refineries consist of finished or semifinished­products that are returned from energy consumers to refineries for processing, blending or sale. They are usually by-products of petrochemical manufacturing. For integrated petrochemical industries, this flow should be estimated. Transfers from one refinery to another within the country are not covered by this data item. 6.52. Refinery intake refers to the amount of oil (including other hydrocarbons and additives) that has entered the refinery process. 6.53. Refinery losses refer to losses during the refinery processes. They are the difference between refinery intake (observed) and the production from refineries (gross refinery output). Losses may occur, for example, during the distillation processes due to evaporation. The reported losses are shown as a positive number in a mass balance. Although there may be volumetric gains, there are no gains in mass. 6.54. Direct use refers to the use of crude oil, NGL and other hydrocarbons directly without being processed in oil refineries. This includes, for example, crude oil burned for electricity generation.  === ires-2018-page-094.pdf === 81 Statistical units and data items Electricity and heat 6.55. For products classified in SIEC, under section 7 (Electricity) and section 8 (Heat), the following list of additional data items applies. Item number Data item 5.1 Gross production (by type of producer, by type of plant and by production process)a 5.2 Own use 5.3 Net production (by type of producer, by type of plant and by production process)a 5.4 Use of energy products (by energy products and by transformation processes) a See section D.1 in chapter V for a list of types of producers, types of plant and production processes. 55 See table 5.2. 6.56. Gross electricity production is the sum of the electrical energy production by all generating units/installations concerned (including pumped storage) measured at the output terminals of the generators. 6.57. Gross heat production is the total heat produced by the installation and includes the heat used by the installation’s auxiliaries that use a hot fluid (liquid fuel heating, etc.) and losses in the installation/network heat exchanges, as well as heat from chemical processes used as a primary energy form. It should be kept in mind that for autoproducers, the production of heat covers only the heat sold to third parties; thus gross heat production for autoproducers is equal to net heat production.55 6.58. Net electricity production is equal to the gross electricity production less the electrical energy absorbed by the generating auxiliaries and the losses in the main generator transformers. 6.59. Net heat production is the heat supplied to the distribution system as determined from measurements of the outgoing and return flows. 6.60. Own use is defined as the difference between the gross and the net production. 6.61. Use of energy products (by energy product and by transformation processes) refers to the quantity of energy products used for the generation of electricity and heat. 3. Data items on production, storage and transmission capacity 6.62. The data items presented in this section refer to the production, storage and transmission capacity of energy. These statistics are important for the assessment of the ability of a country to produce and store energy products, as well as to transmit and distribute electricity. Natural gas Item number Data item 6.1 Peak output 6.2 Gas storage facility—name 6.3 Gas storage facility—type of storage 6.4 Gas storage facility—working capacity 6.63. Peak output. Peak output is the maximum rate at which natural gas can be withdrawn from storage. 6.64. Name of storage facility. The name of the storage facility identifies the facility. Additional information on the location or site of the facility is also important for its proper identification. 6.65. Type of storage capacity. There are three main types of storage in use: (a) Depleted oil and gas fields that are naturally capable of containing the gas and have installations for the injection and withdrawal of the gas; (b) Aquifers, which may be used as storage reservoirs  === ires-2018-page-095.pdf === 82 International Recommendations for Energy Statistics (IRES) provided that they have suitable geological characteristics (e.g. the porous sedimentary layer must be overlaid by an impermeable cap rock); and (c) Salt cavities that may exist naturally or be formed by injecting water and removing the brine. Salt cavities are generally smaller than the reservoirs provided by depleted oil and gas fields or aquifers but offer very good withdrawal rates and are well-suited for peak-shaving requirements. 6.66. Working capacity. Working capacity is the total gas storage capacity minus cushion gas. Cushion gas refers to the volume of gas required as a permanent inventory to maintain adequate underground storage reservoir pressures and deliverability rates throughout the output cycle). Oil Item number Data item 6.5 Refinery capacity 6.67. Refinery capacity is the theoretical maximum capacity of crude oil refineries available for operation at the end of the reference period. For annual data, capacity should be measured where possible on 31 December. Biofuels and waste Item number Data item 6.6 Liquid biofuel plant capacity 6.6.1 Biogasoline plant capacity 6.6.2 Biodiesel plant capacity 6.6.2 Other liquid biofuel plant capacity 6.68. Liquid biofuel plant capacity refers to the production capacity available for operation at the end of the reference period in terms of tons of products per year (for annual data). This information is disaggregated according to the type of plant. Electricity and heat plants Item number Data item 6.7 Net maximum electrical capacity (by type of technology) 6.8 Peak load demand 6.9 Available capacity at time of peak 6.10 Date and time of peak load occurrence 6.69. Net maximum electrical capacity is the maximum active power that can be supplied continuously (i.e., throughout a prolonged period in a day with the whole plant running) at the point of outlet (i.e., after taking the power supplies for the station auxiliaries and allowing for the losses in those transformers considered integral to the station). This assumes no restriction of interconnection to the network. It does not include overload capacity that can only be sustained for a short period of time (e.g., internal combustion engines momentarily running above their rated capacity). 6.70. Peak load demand is the highest simultaneous demand for electricity satisfied during the year. Note that the electricity supply at the time of peak demand may include demand satisfied by imported electricity, or alternatively, the demand may include exports of electricity. Total peak load on the national grid is not the sum of the peak loads during the year at every power station as they may occur at different times. Either synchronized or very frequent data must be available in order to measure the peak load demand. The former is likely to be gathered by the national grid authority, and the latter by some electricity-generating companies.  === ires-2018-page-096.pdf === Statistical units and data items 6.71. Available capacity at time of peak of an installation is the maximum power at which it can be operated under the prevailing conditions at the time, assuming no external constraints. It depends on the technical state of the equipment and its ability to operate and may differ from the net maximum capacity, e.g. due to lack of water for hydro capacity, plant maintenance, unanticipated shutdown, or other outages at the time of peak load. 6.72. Date and time of peak load occurrence consist of the date and time on which the peak load was reached. 4. Data items for assessment of economic performance 6.73. Data items for the assessment of the economic performance of producers and users of energy are important economic indicators that allow for the formulation and monitoring of economic policies related to energy (e.g., impact of taxation on consumers’ behaviour, contribution of the energy industry to the national gross domestic product, etc.). The data items presented below are closely linked with the concepts, definitions and methods of the System of National Accounts 2008 (SNA 2008). 6.74. The data items presented in this section are generally collected as part of economic statistics, thus further reference and detail are provided in the International Recommendations for Industrial Statistics 2008. Item Number Data item 7.1 Consumer prices (end-use) (by energy product) 7.2 Import energy prices (by energy product) 7.3 Export energy prices (by energy product) 7.4 Taxes (by energy product) 7.5 Other taxes on production (by energy product) 7.6 Subsidies received (by energy products) 7.7 Subsidies on products (by energy product) 7.8 Other subsidies on production (by energy product) 7.9 Gross output at basic prices 7.10 Of which: of energy products (by product) 7.11 Total number of persons employed 7.12 Average number of persons employed 7.13 Hours worked by employees 7.14 Gross fixed capital formation 6.75. Prices refer to the actual market price paid for an energy product (or group of products). They correspond to what is commonly referred to as spot prices. Consumer prices refer to purchasers’ prices (SNA 2008, para. 14.46), which are the amount paid by the purchaser. For analytical purposes, countries are encouraged to compile information on the components of the different prices: Producers’ prices = Purchasers’ prices - Wholesale and retail distribution margins (trade margins) - Transportation charges invoiced separately (transport margins) - Non-deductible value added tax (VAT) and Basic prices = Producers’ prices - Taxes on products resulting from production, excluding invoiced VAT - Subsidies on products resulting from production 83  === ires-2018-page-097.pdf === 84 International Recommendations for Energy Statistics (IRES) 6.76. Import prices generally include cost, insurance and freight (CIF) at the point of entry into the importing economy. 6.77. Export prices are valued free on board (FOB) at the point of exit from the exporter’s economy. It includes the cost of transport from the exporter’s premises to the border of the exporting economy. 6.78. Taxes are compulsory unrequited payments, in cash or in kind, made to the government. Two main groups of taxes are identifiable: taxes on products; and other taxes on production. However, only other taxes on production are presented as data item, as these payments are recorded in the business accounts of units. It is recommended that, in statistical questionnaires, countries refer to the specific names or descriptions of taxes as they exist in their national fiscal systems. 6.79. Other taxes on production are taxes that units are liable to pay as a result of engaging in production. As such, they represent a part of production costs and should be included in the value of output. Units pay them irrespective of profitability of production. These taxes consist mainly of taxes on the ownership or use of land, buildings or other assets used in production, or on the labour employed or compensation of employees paid. Examples of such taxes are motor vehicle taxes, duties and registration fees, and levies on the use of fixed assets. Also included are official fees and charges (i.e. duties payable for specific public services, such as the testing of standards of weights and measures, provision of extracts from official registers of crime and the like). 6.80. It may not be possible to collect data on all these taxes at the establishment level; therefore, in such cases the design of statistical questionnaires and subsequent data compilation should clearly indicate the type of taxes that have been reported. 6.81. Subsidies received covers payments that government units make to resident producing units on the basis of their production activities or the quantities or values of the goods or services they produce, sell or import. The classification of subsidies follows closely the classification of taxes. 6.82. Subsidies on products correspond to subsidies payable per unit of a good or service produced, either as a specific amount of money per unit of quantity of a good or service, or as a specified percentage of the price per unit; it may also be calculated as the difference between a specified target price and the market price actually paid by a buyer. 6.83. Other subsidies on production consist of subsidies, except subsidies on products that resident enterprises may receive as a consequence of engaging in production (for example, subsidies on payroll or workforce and subsidies to reduce pollution). 6.84. Gross output at basic prices measures the result of the overall production activity of economic units. The value of production corresponds to the sum of the value of all goods or services actually produced within an establishment and made available for use outside that establishment, plus any goods and services produced for own final use. In order to maintain consistency with the valuation principles for output (production) of other international recommendations on business statistics and national accounts, it is recommended that countries compile the output of establishments at basic prices. However, in circumstances where it is not possible to segregate “taxes and subsidies on products” and “other taxes on production”, valuation of output at factor cost can serve as a second best alternative. 6.85. Gross output of energy products (by product) refers to the output generated by the producing unit for each of the energy products described in SIEC. 6.86. Total number of person employed, average number of persons employed, and hours worked by employees are important data items describing, for example, the contribution of the energy  === ires-2018-page-098.pdf === 85 Statistical units and data items industry to total employment, as well as allowing for the assessment of labour input and labour efficiency in energy production. 6.87. Gross fixed capital formation is measured by the total value of a producer’s acquisitions, less disposals, of fixed assets during the accounting period, plus certain specified expenditures on services that add to the value of non-produced assets. It should include the value of all durable goods expected to have a productive life of more than one year and intended for use by the establishment (land, mineral deposits, timber tracts and the like, buildings, machinery, equipment and vehicles). This data item is a measure of the investments of an economic entity and should be disaggregated by type of asset to provide a basis for a more comprehensive evaluation of the performance of energy industries. 5. Data items on mineral and energy resources 6.88. Data items on mineral and energy resources are important for the assessment of their availability in the environment, as well as for the assessment of their depletion. This information is often used in the compilation of asset accounts in the SNA, as well as in SEEA-Energy. This section is based on the work that has been carried out in the preparation of SEEA-Energy. 6.89. The mineral and energy resources relevant for energy statistics and accounts are a subset of the resources defined in the SEEA Central Framework and comprise the following. Table 6.1 Mineral and energy resources relevant for energy56 56 See SEEA-Energy, table 2.5. 57 See SEEA-Energy, table 5.1 for the definition of these categories in terms of UNFC 2009. Oil resources Natural gas resources Coal and peat resources Uranium and other nuclear fuels 6.90. The United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources (UNFC 2009) provides a scheme for classifying and evaluating these resources according to three dimensions, namely, their economic and social viability, the field project status and feasibility, and the geological knowledge about these resources. SEEA-Energy groups the detailed categories of UNFC into three aggregated classes characterizing the commercial recoverability of the resources as follows.57 Table 6.2 Categorization of mineral and energy resources relevant for energy Class A: Commercially recoverable resources Class B: Potentially commercially recoverable resources Class C: Non-commercial and other known deposits 6.91. The data items on mineral and energy resources consist of the items presented below covering the opening and closing stock levels of the energy resources by type of resources (oil resources, natural gas resources, etc.) and by type of characteristics (commercially recoverable, etc.).  === ires-2018-page-099.pdf === 86 58 International Recommendations for Energy Statistics (IRES) It is important to note that the term stocks is here understood as in the context of SEEA and SNA, where it is used to designate any point-in-time accumulation within the economy, whether they are mineral and energy resources or energy products. What is called stocks in energy statistics is referred to as inventories in the context of SNA and SEEA. Item number Data item 8.1 Opening stocks of mineral and energy resources (by type of resources and by type of characteristics) 8.2 Closing stocks of mineral and energy resources (by type of resources and by type of characteristics) 6.92. The opening and closing stocks of mineral and energy resources58 refer to the amount of the resource at the beginning and end of the reference year by type of resources (as classified in table 6.1) and type of characteristics (as classified in table 6.2). 6.93. It should be noted that these data are generally estimated by geological institutes through geological modelling and not directly collected by the statistical agency in charge of the compilation of energy statistics.