Natural Gas Quality - data publishing

Natural gas comes into the Croatian transmission system from different sources. Entries include onshore and offshore domestic production, import via interconnections with the neighbouring countries Hungary and Slovenia, underground gas storage and the liquified natural gas terminal. Depending on the source it comes from, gas is of different chemical composition. General conditions of gas supply is the document that stipulates standard quality parameters of natural gas entering the Croatian transmission system. Meeting these parameters provides that the gas at the transmission system exits meets stipulated parameters as well. As the transmission system operator, Plinacro does not perform any technological procedures which may have an impact on chemical composition of gas and other gas quality parameters.  

Pursuant to the provisions of the Network Code of the Transmission system the transmission system operator monitors gas quality in the transmission system with the aim to prevent occurrence of gas of non-standard quality. A transmission system operator monitors gas quality by its own system, which enables recording and central collection of natural gas quality data from all sampling locations, regardless of the ownership of the equipment for the gas quality parameters measurement. Since 1 October 2019, gas quality monitoring system consisting of process chromatographic gas analyzers is in use on the transmission system of Plinacro.
A list of all gas sampling locations on the transmission system is published in the Document.
 
Plinacro publishes the following data on the composition of gas through the public web application of the SUKAP information system:

• Data on the average gross calorific value, Wobbe index, methane content and oxygen content for the previous gas day for each transmission system exit which is not part of a joint exit and the quantity-weighted average daily gross calorific value for each joint transmission system exit. 

Also, since 1.6.2025. the following has been published on SUKAP Public Announcement, and no longer on the web page:

• Data on quantity-weighted average gross calorific value for two half-month periods and a full-month period, for each transmission system exit which is not a part of a joint exit, and for each joint transmission system exit, and
• Average daily values of determined gas quality parameters, for all sampling locations. The Excel document for a particular month is announced after the expiry of the first half-month period and it contains temporary data for the first 15 days of that month, and after the expiry of the entire month it is updated with data for the entire month.

The SUKAP Public Announcement contains data from 1 October 2023 onwards.
NOTE: Information on gas quality until 1 October 2023 can be found in the Archive.