ANNUAL QUALITY REPORT

Transcription

1 ANNUAL QUALITY REPORT FOR THE SURVEY ON HOUSEHOLD ENERGY CONSUMPTION (APEGG) FOR 2014 Prepared by: Teja Rutar Date: February /10

2 Table of Contents 0 Methodological Explanations Relevance Rate of Unavailable Statistics Accuracy Sampling Errors Sampling Error Coverage Bias Coverage Bias Non-Sampling Errors Non-Response Errors Unit Non-Response Rate Item Non-Response Rate Imputation Rate Coverage Errors Overcoverage Rate Measurement Errors Editing Rate Timeliness and Punctuality Timeliness Timeliness of the First Results Timeliness of Final Results Punctuality Punctuality of the First Results Accessibility and Clarity Accessibility Means Used for the Dissemination Clarity Results Presented Level (Detail) of Presentation Comparability Comparability over Time Length of Comparable Time Series Breaks in Time Series Geographical Comparability Comparability with Other Members of the European Statistical System Seasonal Adjustment Coherence Coherence between Provisional and Final Data Coherence between Provisional and Final Data Coherence with the Results of the Reference Survey Reference Survey Coherence with Reference Data Costs and Burdens Survey Costs of the Office Burden of Reporting Units /10

3 0 Methodological Explanations Brief Description of the Survey With the survey on household energy consumption we are observing the structure of final energy consumption in households (private dwellings) by energy sources and end use. We are interested in knowing how the energy is used in private dwellings (for space heating and cooling, water heating, lighting, electrical appliances, etc.). We are particularly interested in the use of renewable energy sources (wood, solar energy, etc.). We collect data about: - space heating/cooling, - water heating, - cooking appliances, - electrical appliances, - lighting, - cars. Legal Basis for the Survey The obligation for collecting these data is determined in: Regulation (EC) No. 1099/2008 of the European Parliament and of the Council on energy statistics; Commission Regulation (EU) No. 431/2014 amending Regulation (EC) No. 1099/2008 of the European Parliament and of the Council, as regards the implementation of annual statistics on energy consumption in households. Annual Programme of Statistical Surveys for 2015 (OJ RS, No. 83/2014): Household Energy Consumption (APEGG); number of task: Observation Units The observation unit is a dwelling where the interviewed private household lives. Observation units are private dwellings, thus persons living in collective households (monasteries, old people's homes, etc.) are not included in the survey and can't respond to it. Weekend and holiday apartments are also inadequate for the survey. Coverage Sources for the sample frame of the survey are the Real Estate Register and the Central Population Register. Units are selected with the probability sample. Units are first selected from the sample frame and then connected to the phonebook. The final sample includes selected persons for whom the telephone number was determined. Stratified sampling is used. The sample is stratified by type of the building, by age of the building and by type of the settlement. It is also implicitly stratified by type of the main heating system, by the presence of agricultural activity and statistical region. In 2014, 1,533,699 units were included in the sample frame and 7,141 units persons aged 18 and more, were included in the sample. With the address of the chosen person we determined the dwelling for which we wanted to collect the data. These data were reported by the person who lived in this dwelling and knew the most about energy consumption of it. 3/10

4 Key Variables Key variables are consumed amounts of energy and fuels in households, e.g. firewood for (local/central) heating, wood pellets for (local/central) heating, etc. Key Statistics The key statistics of this survey are as follows: - the total amount of consumed energy and fuels in Slovenian households expressed in their natural units by energy sources, e.g. firewood (t), wood pellets (t), etc. - the total amount of consumed energy and fuels in Slovenian households expressed in energy units by energy sources and by end-use (space heating, water heating, cooking, other). Questionnaire The questionnaire is available on the website (only in Slovene): Methodological Explanations The methodological explanations are available on the website: (Theme: Energy, Sub-theme: Energy Production and Consumption). 4/10

5 1 Relevance 1.1 Rate of Unavailable Statistics The rate of unavailable statistics is 0. 2 Accuracy 2.1 Sampling Errors Sampling Error Estimates and coefficients of variation for the target variables for 2014 are shown in table 2.1. Table 2.1: Estimates and coefficients of variation for the target variables Consumption CV Confidence interval Firewood consumption (t) 1,462,368 3% (1,386,714; 1,538,023) Wood pellets consumption (t) 66,363 13% (49,301; 83,424) Wood chips consumption (t) 25,006 33% (9,066; 40,947) Wood briquettes consumption (t) 3,615 42% (628; 6,603) Wood waste consumption (t) 7,217 42% (1,269; 13,165) Extra light fuel oil consumption (t) 141,115 5% (128,430; 153,800) Liquefied petroleum gas consumption (t) 26,654 7% (22,994; 30,315) Natural gas consumption (1,000 sm 3 ) 132,463 6% (116,751; 148,176) Electricity consumption (GWh) 2,585 1% (2,521; 2,650) Coal consumption (t) 2,023 70% (-740; 4,786) If the coefficient of variation (CV) of the estimate is: - 10% or below (CV <= 10%), the estimate is of acceptable precision and is published without limitations; - in the interval from 10% to 30% (10% < CV <= 30%), the estimate is less precise and is flagged for caution with letter M; - over 30% (CV > 30%), the estimate is too imprecise to be published and therefore suppressed for use by letter N. High coefficients of variation occur in less widely used energy products, which is the result the sample size. 2.2 Coverage Bias Coverage Bias As the survey is conducted on the selected random sample, the coverage bias is not calculated. 5/10

6 2.3 Non-Sampling Errors Non-Response Errors Unit Non-Response Rate Table 2.2: Unit non-response rate Reference period Number of adequate units 5,818 7,087 Number of non-responses 1,873 4,150 Non-response rate (%) In 2014, the unit non-response rate increased due to high rate of cooperation refusals, changed survey method (transition from a combined telephone and field survey to telephone survey) and a large number of non-contacted units Item Non-Response Rate Item non-response rates for a few key variables for 2014 are shown in table 2.3. Table 2.3: Item non-response rates for a few key variables Variable Item non-response rate (%) Firewood consumption for central heating 15.1 Firewood consumption for local heating 9.9 Wood pellets consumption for central heating 13.9 Wood pellets consumption for local heating Imputation Rate Imputation rates for a few key variables for 2014 are shown in table 2.4. Table 2.4: Imputation rates for a few key variables Variable Imputation rate (%) Firewood consumption for central heating 16.3 Firewood consumption for local heating 9.9 Wood pellets consumption for central heating 16.4 Wood pellets consumption for local heating Coverage Errors Overcoverage Rate Table 2.5: Overcoverage rate Reference period Number of units in the address book 6,000 7,141 Number of non-adequate units Overcoverage rate (%) Measurement Errors Editing Rate Editing rates for a few key variables for 2014 are shown in table /10

7 Table 2.6: Editing rates for a few key variables Variable Editing rate (%) Firewood consumption for central heating 16.3 Firewood consumption for local heating 9.9 Wood pellets consumption for central heating 16.4 Wood pellets consumption for local heating 0 3 Timeliness and Punctuality 3.1 Timeliness Timeliness of the First Results Table 3.1: Timeliness of the First Results Reference period Sep Sep Date of publishing Time lag (months) T + 10 T Timeliness of Final Results Provisional data for this survey are not published. The results published in the First Release are also final. In certain cases data can change later due to updating of the model with recent data. 3.2 Punctuality Punctuality of the First Results Table 3.2: Punctuality of the First Results Reference period Sep Sep Announced date Publishing date Difference (days) /10

8 4 Accessibility and Clarity 4.1 Accessibility Means Used for the Dissemination Table 4.1: Means Used for Dissemination, 2014 No.: Mean Used 1 Website (e.g. First Release, E-release) YES 2 Publication in the SI-STAT Data Portal YES 3 Publication in the interactive web tools (e.g. Interactive Statistical Atlas of Slovenia, Thematic NO Cartography) 4 Ad hoc prepared data for users according to their specification YES 5 Data available through telephone answering machine NO 6 General printed publications (e.g. Stat`o`book, Slovenia in Figures) YES 7 Thematic printed publications (e.g. Rapid Reports, Brochures) NO 8 External databases (e.g. Social Science Data Archives, Eurostat, OECD databases) YES 9 Statistically protected micro data NO 4.2 Clarity Results Presented Results are presented in absolute figures and shares. First Release data are presented in tables and charts, in Stat`o`book they are presented also as infographics Level (Detail) of Presentation The results are presented at the national level. The sample is too small to allow the calculation and publication of results for smaller territorial units. Published are data on energy consumption (by end-use and by type of energy source), on electricity consumption (by end-use), on space and water heating systems (by type of heating system and by type of energy source), on equipment of dwellings with light bulbs (by type of bulbs), on equipment of dwellings with electrical appliances and data on their energy labels (by type of electrical appliance), on distance travelled by and fuel consumption of passenger cars according to cubic capacity and fuel type and also some general indicators on energy consumption (equipment of dwellings with air conditioning, solar collectors, heat pumps, etc.). 8/10

9 5 Comparability 5.1 Comparability over Time Length of Comparable Time Series The length of comparable time series is 6 years Breaks in Time Series The Household Energy Consumption Survey was conducted already in 1997 and Since 2010 (data for 2009) the survey is based on a changed methodology, so the data are not directly comparable with the previously collected data. Data are published annually. 5.2 Geographical Comparability Comparability with Other Members of the European Statistical System Data are not comparable to data from other Member States of the European Statistical System as the methodology for the survey was not prescribed by the European Union. From 2016 onwards, reporting these data to Eurostat is mandatory, but Member States use different methodologies for data production. 5.3 Seasonal Adjustment Seasonal adjustment methods are not used in this survey. 6 Coherence 6.1 Coherence between Provisional and Final Data Coherence between Provisional and Final Data Provisional data are not disclosed. Only final data are published. 6.2 Coherence with the Results of the Reference Survey Reference Survey Some data on household energy consumption are collected also in other energy statistics surveys. These data are not directly comparable to the Household Energy Consumption Survey data due to different data collection methodology; namely, data on energy supply are provided to our office from the distribution services and sellers. These data are used for calibration of the model of household energy consumption. 9/10

10 6.2.2 Coherence with Reference Data Table 6.1: Comparison of final energy consumption (TJ) from Household Energy Consumption Survey (APEGG) and from annual energy balance APEGG 53,510 55,803 52,911 51,381 50,746 43,558 Annual energy balance 53,513 55,811 52,889 51,383 50,739 43,556 S2 (%) Source: SURS 7 Costs and Burdens 7.1 Survey Costs of the Office Table 7.1: Survey costs at the Statistical Office Reference period 2009/ Number of working hours spent 3,500 1) 2,491 2) Number of reporting units that had to fill in questionnaires 6,000 7,141 Survey period multiannually multiannually Number of questionnaires per year (total) 6,000 7,141 1) The number of working hours spent for 2009/10 includes hours of full-time employees of SURS during the project period (18 months), while data on the number of hours spent by the subcontractor (the Jožef Stefan Institute) are not included. In addition to full-time employees, 34 interviewers conducted telephone interviewing; they performed hours in 21 days of interviewing. 39 interviewers conducted field interviewing (data on the number of their hours spent are not available). The survey in 2010 was conducted with the financial support from Eurostat (»grant«), which financed 50% of the survey costs. Since then the survey has been included in the regular work of SURS. 2) The number of working hours spent for 2014 includes hours of full-time employees of SURS (2,171) and hours spent by the subcontractor (the Jožef Stefan Institute; 320 hours). In addition to full-time employees, 41 interviewers conducted telephone interviewing; they performed 1,825 hours in 58 working days of interviewing. 7.2 Burden of Reporting Units Table 7.2: Burden of the reporting units Reference period 2009/ Number of reporting units that submitted the data 3,945 2,937 Annual number of questionnaires per unit 1 1 Time spent to fill in a questionnaire (hours) Total time spent (hours) /10