Data for Slovenia
Objectives summarised by: Resolucija o Nacionalnem energetskem programu (ReNEP) (Resolution on the National Energy Programme, Official Gazette of the RS, No. 57/04).

Data source or database: The data on prices of energy products are published by SORS in the SI-STAT Data Portal > Environment and natural resources > Energy > Prices of energy sources for all consumer groups.

Data administrator: Statistical Office of the Republic of Slovenia (Ema Mišič) and Eurostat.

Data acquisition date for the indicator: 14 November 2012.

Methodology and frequency of data collection for the indicator: The data for energy prices are published twice a year; namely, the prices in force on 1 January are published by SORS in the second week of March, and the prices of 1 July of the current year by SORS in the second week of September.
The prices for electricity and natural gas by individual consumer groups are monitored by the Statistical Office of the Republic of Slovenia; since 1992 for electricity and since 1995 for natural gas. The Statistical Office of the Republic of Slovenia also monitors the prices of fuels, but only since 1999. The prices of fuels before that year are available from fuel dealers (Petrol).
The most representative consumer groups for industrial consumers of natural gas and electricity are I3 for consumers of natural gas and Id for consumers of electricity. For household consumers, the most representative consumer groups are D2 for consumers of natural gas and Dc for consumers of electricity.

Data processing methodology: The energy prices published by SORS are current prices. Since these are nominal categories, changes in prices do not reflect real changes. Real changes in prices are reflected only by real prices, which are calculated by the deflation of nominal prices with the GDP deflator, which is published by SORS for every previous year. Energy prices that are indicated in the data sheet are real prices; deflators that converted nominal prices to the level of real prices of 1995 were used for the calculation. The real prices of 1995 were converted into EUR 1995 with the use of the average annual exchange rate of the Bank of Slovenia in 1995. Such calculation enables better comparability of energy prices in Slovenia with average prices in the EU.
Real energy prices are calculated as:

PR_t = [(P_t*1/D_1995,t)/er₁₉₉₅]

PR-real prices, P – current prices, D – deflator, er – exchange rate.

Geographical coverage: EU-27.

Information concerning data quality:
- Advantages and disadvantages of the indicator: The source of basic data for the entire time series for electricity and natural gas is SORS, which enables a more efficient and consistent analysis of individual sectors; only for prices of fuels before 1999, it was necessary to obtain data from the largest fuel dealer in Slovenia (Petrol).
- Relevance, accuracy, robustness, uncertainty:
Reliability of the indicator (archive data): The data reflect the prices by individual consumers groups that were in force on the first day of January and July. SORS publishes prices that are obtained from suppliers of electricity and natural gas, and not directly from energy consumers. In industry, the majority of contracts between electricity suppliers and consumers are concluded for several years. Prices usually differ inside individual consumers of the same consumer group; therefore, we can conclude that SORS' prices most likely do not reflect the actual conditions in the area.
Uncertainty of the indicator (scenarios/projections): Scenarios and projections are not available.
- Overall assessment (1 = no major comments, 3 = data to be considered with reservation):
Relevance: 1
Accuracy: 2
Completeness over time: 1
Completeness over space: 1

Data for the other countries
Data source or database: Eurostat - Tables by themes > Environment and energy > Energy Statistics - prices, Oil bulletin, link Time series – History from 2005 onwards
Data administrator: Eurostat, European Communities, contact: tren-oil-bulletin@ec.europa.eu
Data acquisition date for the indicator: 14 November 2012.
Methodology and frequency of data collection for the indicator:
In the Oil Bulletin database data on motor fuels are gathered weekly, with and without the taxes. Prices on January 4 are used for each country. Methodology of the data collection is described here.

Data processing methodology:
Weighted average prices for each country are used.
Geographical coverage: EU-27.
Information concerning data quality:
- Advantages and disadvantages of the indicator: The source of basic data for the entire time series for the petrol and diesel is Eurostat, which enables a more efficient and consistent analysis of individual sectors.
- Relevance, accuracy, robustness, uncertainty:
Reliability of the indicator (archive data): The data reflect the prices by individual consumers groups that were in force on the first day of January and July. SORS publishes prices that are obtained from suppliers of electricity and natural gas, and not directly from energy consumers. In industry, the majority of contracts between electricity suppliers and consumers are concluded for several years. Prices usually differ inside individual consumers of the same consumer group; therefore, we can conclude that SORS' prices most likely do not reflect the actual conditions in the area.
Uncertainty of the indicator (scenarios/projections): Prices and trends comparison among the EU member states very likely doesn't necessary reflect the reality due to differences in quality of the products and the structure of the fuel market.
- Overall assessment (1 = no major comments, 3 = data to be considered with reservation):
Relevance: 1
Accuracy: 2
Completeness over time: 1
Completeness over space: 1

Other sources and literature:

- AGEN-RS, 2012. Poročilo o stanju na področju energetike v Sloveniji v letu 2011.
- Oil bulletin.
- Uredba o oblikovanju cen naftnih derivatov (Regulation on the price methodology of oil derivatives, Official Gazette of the RS, No. 91/07).