What does the survey comprise?
Providing insight into the supply of crude oil and petroleum products in the Netherlands. Providing information for the Stockholding law 2001 (Wet Voorraadvorming Aardolieproducten) and the International Energy Program Implementation Act (Wet uitvoering Internationaal Energie Programma).
Enterprises based in the Netherlands producing, storing, processing or trading crude oil and/or petroleum products.
Statistics Netherlands has a general business register (ABR) describing the Dutch business population as statistical units. The statistical units Enterprise, Enterprise Group and Local Unit are derived from this register. The register forms the basis for the definition of the population and for the sampling of many business statistics, including the petroleum statistics.
Date/year survey started
The survey was started in 1944.
After one month the flash key figures are published according to international agreements. Provisional figures are published on StatLine in the third month after the month under review and reported in accordance with the international guidelines to the International Energy Agency (IEA) and Eurostat. All figures for the reporting year become definite in the following December.
How is the survey conducted?
Integral observation of the target population. We require a balance sheet of crude oil and petroleum products. For the feedstock these are the petroleum flows in the customs warehouse and within the country. For petroleum products this is always the warehouse and the domestic flows together. The breakdown by country of imports and exports comes from the international trade statistics. There is a special questionnaire for importers of crude oil.
Indigenous production figures come from TNO, the Dutch Organization for applied scientific research.
The survey is conducted with online questionnaires.
These are refineries, companies in petrochemical industry, storage companies and traders based in the Netherlands.
Checking and correction methods
Individual and aggregated figures get a plausibility check. This is done by comparing the previous period with the corresponding periods of previous years. And the opening stock of the current period must be equal to the closing stock of the last period.
Supply and consumption must be in balance for each energy commodity and each company.
We examine the return of the processes for each company. For blending (mixing petroleum products) there should be no loss of yield. For refining a return of around 98 percent is acceptable. In the petrochemical industry the return is less than 95 percent.
We check deliveries between the companies in the survey. This shows the supply and consumption of small traders. Imports and exports are compared to the international trade statistics.
Corrections for previous months are also included in the current month. Corrections resulting from the integration in the Dutch energy balance (NEH) are made in accordance with the publication strategy of the Dutch energy balance.
Quality of the results
Provisional and definite figures are reported in million kilograms.
From 1980 onwards figures can be compared well. Petroleum products regularly change as new products come on the market and old products disappear.
In 2015 the figures of the energy balance sheet have been revised for 1995 up to and including 2013. The main reasons for this were a break in the time series for the sector petrochemicals, the possibility to use connection records of the energy companies to determine the final consumption of natural gas and electricity and the availability of new sources of information of the consumption of fuels for transport and mobile sources. Furthermore, a number of changes of smaller size, such as correcting errors found and adjustment of figures by the availability of new information.
* All completed forms are checked. Any questions will be discussed with the respondent. There are several levels of checking, as described in the correction methods.
* Where possible, results are compared with other figures of Statistics Netherlands, e.g. the international trade statistics.
* Statistics Netherlands follows the international energy statistics quality guidelines (see the Energy Statistics Manual by IEA and Eurostat).
* The observation strategy is designed to avoid double counting. This is why the respondents report the stocks in their warehouses. Checking mutual deliveries also aims to avoid double counting.