REPUBLIC OF SLOVENIA

ANNUAL QUALITY REPORT FOR THE SURVEY HOUSEHOLD ENERGY CONSUMPTION SURVEY FOR 2010

Prepared by: Teja Rutar Date: May 2012

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

1/10

Table of contents 0 1 2

3

4

5

6

7

Basic Data.......................................................................................................................... 3 Relevance........................................................................................................................... 4 1.1 Rate of Missing Statistics ........................................................................................... 4 Accuracy............................................................................................................................ 4 2.1 Sampling Errors.......................................................................................................... 4 2.1.1 Sampling Error................................................................................................... 4 2.2 Non-sampling Errors .................................................................................................. 5 2.2.1 Non-response Errors .......................................................................................... 5 2.2.1.1 Unit Non-response Rate ................................................................................. 5 2.2.1.2 Item Non-response Rate ................................................................................. 5 2.2.1.3 Imputation Rate .............................................................................................. 5 2.2.2 Coverage Errors................................................................................................. 5 2.2.2.1 Over-coverage Errors .................................................................................... 5 2.2.2.2 Under-coverage Errors .................................................................................. 5 2.2.3 Measurement Errors .......................................................................................... 5 2.2.3.1 Editing Rate.................................................................................................... 5 Timeliness and Punctuality ............................................................................................. 6 3.1 Timeliness .................................................................................................................. 6 3.1.1 Timeliness of the First Release........................................................................... 6 3.1.2 Timeliness of Final Results ................................................................................ 6 3.2 Punctuality.................................................................................................................. 6 3.2.1 Punctuality of the First Release ......................................................................... 6 Accessibility and Clarity .................................................................................................. 7 4.1 Accessibility ............................................................................................................... 7 4.1.1 Means Used for the Dissemination of the Results.............................................. 7 4.1.2 Rate of Means Used............................................................................................ 7 4.2 Clarity......................................................................................................................... 7 4.2.1 Results Presented ............................................................................................... 7 4.2.2 Level (detail) of Presentation ............................................................................. 7 Comparability................................................................................................................... 8 5.1 Comparability over Time ........................................................................................... 8 5.1.1 Length of Comparable Time Series .................................................................... 8 5.1.2 Break in Time Series .......................................................................................... 8 5.2 Geographical Comparability ...................................................................................... 8 5.2.1 Comparability with Other Members of the European Statistical System........... 8 5.3 Seasonal Adjustment .................................................................................................. 8 Coherence.......................................................................................................................... 8 6.1 Coherence between Provisional and Final Data......................................................... 8 6.1.1 Coherence between Provisional and Final Data ............................................... 8 6.2 Coherence with the Results of the Reference Survey ................................................ 8 6.2.1 Reference Survey ................................................................................................ 8 6.2.2 Coherence with Reference Data......................................................................... 9 Costs and Burdens.......................................................................................................... 10 7.1 Survey Costs of the Office ....................................................................................... 10 7.2 Cost and Burden of Reporting Units ........................................................................ 10

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

2/10

0

Basic Data

Brief Description of the Survey The purpose of the Household Energy Consumption Survey (APEGG) is to determine the structure of energy consumption in households by energy sources and by end-use. In the context of this survey data on electrical appliances and cars are also collected. The survey is based on the National Statistics Act and the current Annual Programme of Statistical Surveys. 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 The sample frame for the survey is the Central Population Register, from which we select persons aged 18 or more. With the address of the chosen person we determine the dwelling for which we want to collect the data. These data are reported by the person who lives in this dwelling; the most suitable is that the data are reported by the person who knows the most about energy consumption of this dwelling. The sampling plan is stratified in two stages. It is explicitly stratified by type of the settlement (by size and by share of agricultural households) and by statistical region, and implicitly stratified by the presence of agricultural activity, by the main heating system in the building, by the age of the building and by the number of dwellings in the building. In 2010, 6,000 persons were included in the sample. Key Variables In the Household Energy Consumption Survey key variables are consumed amounts of energy and fuels in households, e.g. consumed amount of extra light fuel oil, natural gas, wood fuels, 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: o extra light fuel oil (t), o natural gas (1,000 Sm3), o firewood (t), o wood chips (t), o wood pellets (t), o wood briquettes (t), o wood waste (t), o liquefied petroleum gas (t), o electricity (GWh), o coal (t), o district heat (TJ), Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

3/10

-

o solar energy (TJ) in o geothermal energy (TJ). 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 in Slovene on the website: http://www.stat.si/doc/vprasalniki/APEGG-VPR_2010.pdf 1

Relevance

1.1 Rate of Missing Statistics In this survey, there are no statistics prescribed with the regulation, so the rate of missing statistics is 0. 2

Accuracy

2.1

Sampling Errors

2.1.1 Sampling Error Sampling errors of estimates occur because only a selected random sample of units is included in the survey and not all units of the target population. Sampling errors are determined by the sampling plan, sample size and variability of the data. Therefore estimates have different accuracy. Sampling errors are calculated using the coefficient of variation (CV). Data users are warned about less accurate estimates with special marks or sometimes the estimates are not published. Table 2.1.: Estimates and coefficients of variation for the target variables for 2010 Consumption

CV

1,450,677

2.9

Wood chips consumption (t)

14,508

25.5

Wood pellets consumption (t)

5,217

35.7

Wood briquettes consumption (t)

3,101

32.4

28,625

19.2

244,493

3.9

25,901

6.3

76,645

11.0

2,730

1.5

630

83.4

26

100.0

Firewood consumption (t)

Wood waste consumption (t) Extra light fuel oil consumption (t) Liquefied petroleum gas consumption (t) 3

Natural gas consumption (1,000 sm ) Electricity consumption (GWh) Coal consumption (t) Petroleum consumption (1,000 l)

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

4/10

2.2

Non-sampling Errors

2.2.1 Non-response Errors 2.2.1.1 Unit Non-response Rate Table 2.2.: Unit non-response rate Number of adequate units Number of non-responses Non-response rate

2010 5,818 1,873 32.2%

2.2.1.2 Item Non-response Rate Item non-response occurs when the interviewed person could not or did not want to answer a particular question. We imputed approximately 20% of the variables. The average nonresponse rate was 2%. Only eight variables had non-response rates higher than 10%. Most responses were missing on the monthly quantity of consumed electricity (60%). This figure was estimated based on monthly expenditure on electricity; the non-response rate for this figure was a little over 4%. 2.2.1.3 Imputation Rate We imputed all target variables where data were missing or where the non-response rate was approximately 20%. 2.2.2 Coverage Errors 2.2.2.1 Over-coverage Errors Among the 6,000 units in the sample 182 (or 3%) were inadequate. Inadequate units are for example unoccupied dwellings, holiday apartments, if the household lives in the chosen dwelling for less than 12 months or units that are found to be institutions, collective households or business premises. 2.2.2.2 Under-coverage Errors Under-coverage errors occur because some units are not included in the sample frame. Such units are dwellings and households without any person with registered permanent residence. 2.2.3 Measurement Errors 2.2.3.1 Editing Rate During the processing of the data we corrected some outstanding values. The share of correction for these variables was less than 0.5%. Most corrections were done on the monthly expenditure on electricity (2%).

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

5/10

3

Timeliness and Punctuality

3.1

Timeliness

3.1.1 Timeliness of the First Release The timeliness of the First Release is determined as the difference between the date of the First Release and the end of the reference period. In the table, the timeliness of the First Release is given in the form T + x, where T is the end of the reference period, and x is the number of days until the release. Table 3.1:1. Timeliness of the First Release Reference period

1. 9. 2009 – 1. 9. 2010

Date of publishing

12. 7. 2011

Time lag

T + 314 days

3.1.2 Timeliness of Final Results Provisional data for this survey are not published. 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

3.2.1 Punctuality of the First Release Punctuality of the first release of the data is determined as the difference between the announced and actual publication date. Table 3.2: Punctuality of the First Release Reference period

1. 9. 2009 – 1. 9. 2010

Announced date

23 .6 .2011

Publishing date

12. 7. 2011

Difference

19 days

Delay in the publication of results was due to technical difficulties. Since the survey was conducted as a pilot project, we didn't have reliable data on the duration of individual phases of the survey and this also affected the delay. On the basis of the implemented project we can now predict and determine the precise deadlines for the implementation of the various phases of the survey and we do not expect any more delays in the future.

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

6/10

4

Accessibility and Clarity

4.1

Accessibility

4.1.1 Means Used for the Dissemination of the Results Table 4.1: Means of dissemination No.: Mean Website 1 (e.g. First Release, E-release)

Used YES

2 Publication in the SI-STAT Data Portal Publication in the interactive web tools (e.g. Interactive Statistical Atlas of Slovenia, Thematic 3 Cartography)

YES

4 Ad hoc prepared data for users according to their specification

YES

5 Data available through telephone answering machine General printed publications 6 (e.g. Statistical Yearbook, Slovenia in Figures) Thematic printed publications 7 (e.g. Rapid Reports, Brochures) External databases 8 (e.g. Social Science Data Archives, Eurostat, OECD databases)

NO

YES

9 Statistically protected micro data

NO

10 Preliminary access to data according to standard protocol

NO

YES YES

NO

4.1.2 Rate of Means Used The rate of means used for data dissemination was 60%. 4.2

Clarity

4.2.1 Results Presented Results are presented in absolute figures and shares. First Release data are presented in tables and charts. 4.2.2 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.).

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

7/10

5

Comparability

5.1

Comparability over Time

5.1.1 Length of Comparable Time Series The Household Energy Consumption Survey was conducted in 1997 and 2003. The present survey is based on a changed methodology, so the data are not directly comparable with the previously collected data. From now on the data will be published annually. For now, data on energy consumption by end-use and energy source, data on electricity consumption and data on types and sources for space and water heating are available for 2009 and 2010, while other data are available only for 2010. 5.1.2 Break in Time Series See 5.1.1. 5.2

Geographical Comparability

5.2.1 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. Individual Member States implement various pilot projects co-financed by Eurostat, but at different scales and with different methodologies. 5.3 Seasonal Adjustment Seasonal adjustment methods are not used in this survey. 6

Coherence

6.1

Coherence between Provisional and Final Data

6.1.1 Coherence between Provisional and Final Data The published data are final; however, in certain cases data can change later due to updating of the model with recent data. 6.2

Coherence with the Results of the Reference Survey

6.2.1 Reference Survey Data on household energy consumption are also collected in other energy statistics surveys. These data are not directly comparable to 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. Data on household energy consumption are also collected through a survey on energy efficiency in Slovenia (»REUS«), carried out by a private company (Informa Echo) together with members of the network of business-social utility called »Sinergija« and each year with various survey participants. These results are also not directly comparable due to different methodologies. In addition, REUS focuses more on energy management than on the quantity of consumed energy and fuels. Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

8/10

Data on equipment of dwellings with (some) electrical appliances are in SORS also collected with the Household Budget Survey (APG) and the Survey on Living Conditions (AŽP). Surveys are not directly comparable due to different methodologies. In addition, data from APEGG relate to dwellings, while data from APG and AŽP relate to households. 6.2.2 Coherence with Reference Data Table 6.1: Comparison of Household Energy Consumption Survey data and data on energy supply from other energy statistics surveys ENERGY SUPPLY ENERGY SOURCE APEGG (2010) DATA (2010) Extra light fuel oil (t) 244,493 267,000 Natural gas (1,000 Sm3)

76,645

140,000

1,450,677

…

Wood chips (t)

14,508

…

Wood pellets (t)

5,217

…

Wood briquettes (t)

3,101

…

Wood waste (t)

28,625

…

Liquefied petroleum gas (t)

25,901

33,000

2,730

3,219

630

…

26

…

Firewood (t)

Electricity (GWh) Coal (t) Petroleum (1,000 l) … not available Source: SORS

Table 6.2: Comparison of Household Energy Consumption Survey data on shares of dwellings1) with electrical appliances and data from APG and AŽP (%) ELECTRICAL APPLIANCE

APEGG (2010)

Washing machine Dryer

APG (2009)

AŽP (2010)

92

96.9

98

20.4

26.2

…

6

…

…

Washing and drying machine Refrigerator or refrigerator with freezer Upright or chest freezer

99.3

98.3 (refrigerator)

…

55.8

80.3

…

Dishwasher

49.5

50.2

…

Oven

76.3

…

…

Microwave oven

50.2

…

Television

96.9

98 (colour TV)

61

52.7 97.4 (colour TV), 5.5 (black and white TV) 63.7

80.6

80.3

81

Personal computer Passenger car … not available 1) Data from APG and AŽP relate to households. Source: SORS

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

66

9/10

7

Costs and Burdens

7.1

Survey Costs of the Office

Table 7.1: Survey costs at the Statistical Office Number of working hours spent Number of reporting units that had to fill in questionnaires Period Number of questionnaires per year (total)

3,500* 6,000 Annual 6,000

* The number of working hours spent includes hours of full-time employees of SORS 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 1431.5 hours in 21 days of interviewing. 39 interviewers conducted field interviewing (data on the number of their hours spent are not available). The survey was in 2010 conducted with financial support from Eurostat (»grant«), which financed 50% of the survey costs. From now on the survey will be included in the regular work of our office. 7.2

Cost and Burden of Reporting Units

Table 7.2: Burden and costs of the reporting units Number of reporting units that submitted the data Annual number of questionnaires per unit Time spent to fill in a questionnaire (hours) Total time spent (hours)

3,945 1 0.25 986.25

Litostrojska cesta 54, SI-1000 Ljubljana, Slovenia Phone: +386 1 241 54 00; fax: +386 1 241 53 44; e-mail: [email protected]; website: www.stat.si

10/10