=== ires-2018-page-001.pdf === United Nations  === ires-2018-page-002.pdf === ST/ESA/STAT/SER.M/93 Department of Economic and Social Affairs Statistics Division Statistical Papers Series M No. 93 International Recommendations for Energy Statistics (IRES) United Nations New York, 2018  === ires-2018-page-003.pdf === ii Department of Economic and Social Affairs The Department of Economic and Social Affairs of the United Nations Secretariat is a vital interface between global policies in the economic, social and environmental spheres and national action. The Department works in three main interlinked areas: (i) it compiles, generates and analyses a wide range of economic, social and environmental data and information on which States Members of the United Nations draw to review common problems and to take stock of policy options; (ii) it facilitates the negotiations of Member States in many intergovernmental bodies on joint courses of action to address ongoing or emerging global challenges; and (iii) it advises interested Governments on the ways and means of translating policy frameworks developed in United Nations conferences and summits into programmes at the country level and, through technical assistance, helps build national capacities. Note The designations used and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The term “country” as used in this publication also refers, as appropriate, to territories or areas. Symbols of United Nations documents are composed of capital letters combined with figures. Mention of such a symbol indicates a reference to a United Nations document. ST/ESA/STAT/SER.M/93 United Nations Publication Sales No. E.14.XVII.11 ISBN: 978-92-1-161584-5 eISBN: 978-92-1-056520-2 Copyright © United Nations, 2017 All rights reserved  === ires-2018-page-004.pdf === iii Contents Page Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix List of abbreviations and acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Chapter I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 A. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 B. Purpose of the international recommendations for energy statistics . . . . . . . . . . 3 C. Users and uses of energy statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 D. IRES development process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 E. Structure of IRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 F. Summary of recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 G. Implementation and revision policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Chapter II. Scope of energy statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 A. Energy and energy statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. Basic concepts and boundary issues: an overview . . . . . . . . . . . . . . . . . . . . . . . . 18 Chapter III. Standard International Energy Product Classification . . . . . . . . . . . . . . . . . . . . 21 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. Purpose and scope of SIEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 C. Classification criteria and coding system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Coding system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 D. Definitions of energy products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Chapter IV. Measurement units and conversion factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 B. Measurement units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 1. Original units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2. Common units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 C. Calorific values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 1. Gross and net calorific/heating values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 2. Default vs. specific calorific values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3. How to calculate average calorific values . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 4. Default calorific values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 5. Units recommended for dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Chapter V. Energy flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 B. Concept of energy flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55  === ires-2018-page-005.pdf === iv International Recommendations for Energy Statistics (IRES) Page C. Definition of main energy flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 D. Energy industries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 1. Electricity and heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 2. Transformation processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 E. Other energy producers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 F. Energy consumers and energy uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 1. Energy consumers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 2. Cross-classification of uses and users of energy . . . . . . . . . . . . . . . . . . . . . . 66 Chapter VI. Statistical units and data items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 B. Statistical units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 1. Statistical units and their definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 2. An illustrative example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 3. Statistical units for energy statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 C. Reference list of data items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 1. Characteristics of statistical units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 2. Data items on energy flows and stock levels . . . . . . . . . . . . . . . . . . . . . . . . . 78 3. Data items on production, storage and transmission capacity . . . . . . . . . . . 81 4. Data items for assessment of economic performance . . . . . . . . . . . . . . . . . . 83 5. Data items on mineral and energy resources . . . . . . . . . . . . . . . . . . . . . . . . 85 Chapter VII. Data collection and compilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 A. Legal framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 B. Institutional arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 C. Data collection strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 1. Scope and coverage of data collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 2. Organization of data collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 D. Data sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 1. Statistical data sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 2. Administrative data sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 E. Data compilation methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Chapter VIII.Energy balances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 B. Scope and general principles of energy balance compilation . . . . . . . . . . . . . . . . 102 C. Structure of energy balance: an overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 1. Top block—energy supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 2. Middle block—transfers, transformation, use and losses . . . . . . . . . . . . . . . 106 3. Bottom block—final consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 4. Statistical difference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 D. Templates of detailed and aggregated energy balances . . . . . . . . . . . . . . . . . . . . . 109 E. Data reconciliation and estimation of missing data . . . . . . . . . . . . . . . . . . . . . . . 112 1. Accuracy requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 2. Estimation of missing data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 3. Reconciliation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 F. Commodity balances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113  === ires-2018-page-006.pdf === v Page Chapter IX. Data quality assurance and metadata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 B. Data quality, quality assurance and quality assurance frameworks . . . . . . . . . . . 115 1. Data quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 2. Quality assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 3. Data quality assurance frameworks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 4. Obectives, uses and benefits of quality assurance frameworks . . . . . . . . . . . 118 5. Dimensions of quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 6. Interconnectedness and trade-offs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 C. Measuring and reporting on the quality of statistical outputs . . . . . . . . . . . . . . . 121 1. Quality measures and indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 2. Examples and selection of quality measures and indicators . . . . . . . . . . . . . 122 3. Quality reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 4. Quality reviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 D. Metadata on energy statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Chapter X. Dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 A. Importance of energy statistics dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 B. Data dissemination and statistical confidentiality . . . . . . . . . . . . . . . . . . . . . . . . 130 C. Reference period and dissemination timetable . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 D. Data revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 E. Dissemination formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 F. International reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Chapter XI. Uses of basic energy statistics and balances . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 B. The System of Environmental-Economic Accounting for Energy . . . . . . . . . . . . 135 1. Main differences between energy balances and energy accounts . . . . . . . . . 136 2. Adjustments for the compilation of energy accounts . . . . . . . . . . . . . . . . . . 138 C. Energy indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 D. Greenhouse gas emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 1. Climate change and GHG emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 2. IPCC guidelines for estimating GHG emissions . . . . . . . . . . . . . . . . . . . . . 142 3. Energy emissions and energy statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Annex A. Primary and secondary products; renewables and non-renewables . . . . . . . . . 145 Annex B. Additional tables on conversion factors, calorific values and measurement units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153  === ires-2018-page-007.pdf === vi International Recommendations for Energy Statistics (IRES) TABLES 1.1 Summary of the main recommendations and encouragements contained in IRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.1 Standard International Energy Product Classification (SIEC) . . . . . . . . . . . . . . . 24 4.1 Default net calorific values for energy products . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4.2 Influence of moisture content on net calorific values of standard fuelwood (wood with one per cent ash content) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.3 Conversion table for fuelwood (wood with 25 per cent moisture content) . . . . . . 52 4.4 Recommended units for dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 5.1 Energy industries with reference to the relevant ISIC category . . . . . . . . . . . . . . 59 5.2 Main activity producers and autoproducers of electricity and heat . . . . . . . . . . . 62 5.3 Main categories of energy consumers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 5.4 Mode of transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.1 Mineral and energy resources relevant for energy56 . . . . . . . . . . . . . . . . . . . . . . 85 6.2 Categorization of mineral and energy resources relevant for energy . . . . . . . . . . . 85 8.1 Template of a detailed energy balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8.2 Template of an aggregated energy balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 11.1 Energy Indicators linked to the social dimension . . . . . . . . . . . . . . . . . . . . . . . . 139 11.2 Energy Indicators linked to the economic dimension . . . . . . . . . . . . . . . . . . . . . 140 11.3 Energy Indicators linked to the environmental dimension . . . . . . . . . . . . . . . . . 141 Boxes 1.1 The United Nations Fundamental Principles of Official Statistics . . . . . . . . . . . . 4 4.1 International System of Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1 Principal, secondary and ancillary activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 9.1 Template for a Generic National Quality Assurance Framework (NQAF) . . . . . 117 9.2 Selected Indicators for Measuring the Quality of Energy Statistics . . . . . . . . . . . 123 9.3 Metadata items for statistical releases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 11.1 Methods for the estimation of GHG emissions from fossil fuel combustion . . . . 143 FIGURES 5.1 Diagram of the main energy flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 5.2 Cross classification of uses and users of energy . . . . . . . . . . . . . . . . . . . . . . . . . . 67 6.1 Example of a large oil corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 8.1 Uses of energy and their presentation in an energy balance . . . . . . . . . . . . . . . . . 109  === ires-2018-page-008.pdf === vii Preface The International Recommendations for Energy Statistics (IRES) provide a comprehensive methodological framework for the collection, compilation and dissemination of energy sta- tistics in all countries irrespective of the level of development of their statistical system. In particular, IRES provides of a set of internationally agreed recommendations covering all aspects of the statistical production process, from the institutional and legal framework, basic concepts, definitions and classifications to data sources, data compilation strategies, energy balances, data quality issues and statistical dissemination. IRES was prepared in response to the request of the United Nations Statistical Com- mission, at its thirty-seventh session (7–10 March, 2006), to review the United Nations manuals on energy statistics, develop energy statistics as part of official statistics, harmonize energy definitions and compilation methodologies and develop international standards in energy statistics. The preparation of IRES was carried out by the United Nations Statistics Division (UNSD) in close cooperation with the Oslo Group on Energy Statistics and the Intersecre- tariat Working Group on Energy Statistics (InterEnerStat). A major milestone of IRES is the Standard International Energy Product Classifica- tion (SIEC), which is the first standard classification for energy products. It has been built on a set of internationally harmonized definitions of energy products developed by InterEnerStat as mandated by the United Nations Statistical Commission. The adoption of SIEC as an international standard classification for energy products represents a significant step forward for energy statistics at the international level. SIEC not only provides a unified set of product definitions, but also uses a standard coding scheme and a common hierarchy of categories, and provides links to other internationally agreed product classifications, such as the Central Product Classification (CPC) and the Harmonized Commodity Description and Coding System (HS). In addition to its use within traditional forms of energy statistics, such as energy balances, SIEC may also serve in frameworks that aim to combine energy statistics with other statistical domains, such as energy accounts used within the field of environmental-economic accounting. The present document has undergone an extensive preparation process that included consultations with experts, two rounds of worldwide consultation and a final review by the Expert Group on Energy Statistics. The United Nations Statistical Commission, at its forty- second session (22–25 February 2011), adopted IRES as a statistical standard and encouraged its implementation in all countries. The Commission also supported the work of UNSD on the Energy Statistics Compilers Manual to provide additional practical guidelines in the col- lection and compilation of energy statistics.  === ires-2018-page-009.pdf ===  === ires-2018-page-010.pdf === ix Acknowledgements The International Recommendations for Energy Statistics have been prepared by the United Nations Statistics Division in close collaboration with the Oslo Group on Energy Statistics and the Intersecretariat Working Group on Energy Statistics. The process also involved other experts who provided advice on specific topics, countries and international/regional organiza- tions participating through two rounds of global consultation, and the participants of the Expert Group on Energy Statistics, who reviewed the document prior to its submission to the Statistical Commission. Members of the Oslo Group on Energy Statistics who contributed to the draft- ing and review of the document include: Mr. G. Brown (Australia), Mr. W. Bitterman (Austria), Mr. Y. Yusifov (Azerbaijan), Mr. J. Lacroix (Canada), Mr. A. Kohut (Can- ada), Mr. A. A. Zarnaghi (Denmark), Mr. T. Olsen (Denmark), Mr. P. K. Ray (India), Ms. G. S. Rathore (India), Mr. M. Howley (Ireland), Mr. C. R. López-Pérez (Mexico), Mr. H. Pouwelse (Netherlands), Mr. A. Tostensen (Norway), Ms. K. Kolshus (Norway), Mr. O. Ljones (Norway), Ms. J. E. W. Toutain (Norway), Mr. S. Peryt (Poland), Mr. A. Gon- charov (Russia), Mr. J. Subramoney (South Africa), Mr. P. Westin (Sweden), Mr. I. MacLeay (United Kingdom), Mr. P. Kilcoyne (United States), Mr. A. Gritsevskyi (International Atomic Energy Agency), Mr. J. Y. Garnier (International Energy Agency), Ms. K. Treanton (Inter­ national Energy Agency), Mr. P. Loesoenen (Eurostat) and Mr. R. Mertens (Eurostat). UNSD is grateful to Mr. Ljones and Mr. Garnier for leading the Oslo Group and the Intersecretriat Working Group on Energy Statistics, respectively, and their contribution to the preparation of IRES. The preparation of IRES was undertaken under the supervision and guidance of Mr. V. Markhonko (UNSD) and concluded under the overall supervision of Mr. R. Becker (UNSD). Mr. Markhonko, Ms. I. Di Matteo, Mr. L. Souza, Mr. O. Andersen, Mr. A. Black- burn and Mr. Becker were involved in the drafting of the text at various stages of the drafting process.  === ires-2018-page-011.pdf ===  === ires-2018-page-012.pdf === xi List of abbreviations and acronyms API American Petroleum Institute BPM6 Balance of Payments and International Investment Position Manual Btu British thermal unit CHP Combined Heat and Power CPC Central Product Classification DQAF Data Quality Assessment Framework EEA European Environmental Agency ESCM Energy Statistics Compilers Manual Eurostat Statistical Office of the European Communities GCV Gross Calorific Value GDP Gross Domestic Product GHG Greenhouse Gas GTL Gas-to-Liquids GWh Gigawatt-hour HS Harmonized Commodity Description and Coding System IEA International Energy Agency InterEnerStat Intersecretariat Working Group on Energy Statistics IPCC Intergovernmental Panel on Climate Change IRES International Recommendations for Energy Statistics ISIC International Standard Industrial Classification of All Economic Activities LNG Liquefied Natural Gas LPG Liquefied Petroleum Gas kWh Kilowatt-hour NQAF National Quality Assurance Framework NCV Net Calorific Value NGL Natural Gas Liquid OECD Organisation for Economic Co-operation and Development SBP Special Boiling Point SDMX Statistical Data and Metadata Exchange SEEA System of Environmental-Economic Accounting  === ires-2018-page-013.pdf === SEEA-Energy System of Environmental-Economic Accounting for Energy SI Systèmes International d’Unités SIEC Standard International Energy Product Classification SIMS Single Integrated Metadata Structure SNA System of National Accounts TES Total Energy Supply Tce Ton of coal equivalent Toe Ton of oil equivalent UN United Nations UNFC United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources UNFCCC United Nations Framework Convention on Climate Change UNSD United Nations Statistics Division VAT Value added tax