ISO INTERNATIONAL STANDARD 50049 First edition 2020-09 Calculation methods for energy efficiency and energy consumption variations at country, region and city levels Methode de calcul pour I'efficacité énergétique et les variations de consommation d'energie aux niveaux national,regional eturbain Reference number IS0 50049:2020(E) ISO IS02020 IS0 50049:2020(E) COPYRIGHTPROTECTEDDOCUMENT @IS02020 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below or Iso's memberbody in the country ofthe requester. ISO copyright office CP 40i : Ch.de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22.749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2020 - All rights reserved IS0 50049:2020(E) Contents Page Foreword ..V Introduction. .. i. 1 Scope. 2 Normative references 3 Terms and definitions 4 Factors to be calculated 4.1 General .4 4.1.1 Overview of methods included in the document ..4 4.1.2 Objectives of calculations. 4 4.1.3 Types of explanatory factors to be calculated ..5 4.2 Indicators,methods and applications 7 4.2.1 Indicators 4.2.2 Types of data used. 7 4.2.3 Structure effects .8 4.2.4 Indicatorchoicefor energy efficiencyand energysavings calculation .8 4.2.5 Climaticcorrectionsofenergyconsumption .9 5 Evaluation of structure effects in the variation ofenergy intensity .9 5.1 General .9 5.2 Calculation methods. .10 5.2.1 Introduction to the calculation of structureeffect .10 5.2.2 Decomposition of the energy intensity variation with the Divisia method .11 5.3 Calculation issues related to structure effects ..12 5.3.1 .12 General. 5.3.2 OptionsofcalculationoftheDivisiadecomposition 5.3.3 Disaggregation level. ..14 5.3.4 Chained or unchained calculation ..14 6 Calculation ofenergy efficiency indices .14 6.1 Objective and overview of calculation. .14 6.2 General calculation .15 .15 6.2.1 General 6.2.2 Step1:Selection of subsectors orenergyuses .15 6.2.3 Step 2: Choice of indicators .15 6.2.4 Step 3: Calculation of indicator values. .16 6.2.5 Step 4: Calculation of indicator trends as index ..16 6.2.6 Step5:Calculation ofweightingfactors .16 6.2.7 Step6:Calculationof energyefficiencyindicesbysector ..17 6.2.8 Step7:Calculationof an overall energy efficiency index. .18 6.3 Computational issues in the calculation of the energy efficiency indices .18 6.3.1 General. ..18 6.3.2 Options for calculation. .18 6.3.3 Indicatorsresulting innegativeenergy efficiencyimprovement .19 6.4 Reliability of energy efficiencyindices. .19 6.4.1 General. .19 6.4.2 Status of data sources. .20 6.4.3 Appropriateness of the indicator 20 6.4.4 Length of period. .20 7 Decompositionanalysis ofenergy consumptionvariation .20 7.1 Objective and overview of calculation 20 7.2 General calculation. .21 7.2.1 .21 General. 7.2.2 Definition of explanatoryfactors .21 7.2.3 Calculation ofthe activityfactor .22 @IS0 2020 -All rights reserved iii