SBS and POS

On this web page we publish the System Balance Signal (SBS). The System Balance Signal is the aggregation of the Portfolio Imbalance Signals (POSs) of all shippers active in our network.

By clicking on the link ‘Actual graph’, you can view the latest SBS status. The graph shows a short history of the SBS and the prediction for the coming hour (the prognosis value). In addition to the SBS, the graph also shows the sum total of the helpers, the sum total of the causers and the buffer zones.

By clicking on the second link ‘Download most recent data’, you can download the most recent data as an XML file. The time format is displayed in CET!

A 31-day history of the SBS can be obtained by clicking on the link ‘Historical graph’. You can zoom in by selecting a part of the graph.

 

The balancing regime is based on near-real time information about the cumulative balancing position of every shipper (portfolio imbalance signal or POS) and of the system (system balance signal or SBS) as a whole. The SBS is equivalent to the sum total of all POSs and reflects the balancing position of the network system.

If we define “damping” as the difference between planned exit and entry submitted by a shipper in a programme, we derive a definition for imbalance: imbalance is the difference – on an hourly basis – between the damping in the programme and the difference between the entry and exit actually realised. For programmes without damping, planned entry and exit are equal, also on an hourly basis. In that case, the imbalance is the difference between the near-real time entry and exit allocations.

The programmes (and consequently, the damping) are fixed the day before the actual day of transportation.

Depending on the type of entry and exit points in a portfolio, in practice “near-real time” means “with a delay of approximately 5 minutes”. Using the near-real time allocations, we calculate the final near-real time imbalance for each portfolio every hour (if a portfolio consists of an entry and an exit programme, the net imbalance is calculated). The hourly imbalance is added to the POS of the previous hour to calculate the POS for this hour. When all the POSs have been calculated, the SBS is calculated as the sum of all POSs.

The POS will become final approximately 20 minutes after the hour. During the hour, we calculate the expected SBS every 5 minutes on the basis of the expected POSs for the end of that hour. The expected SBS is used to determine if a balancing action should be started on the ICE Endex Gas Exchange.

If we define “damping” as the difference between planned exit and entry submitted by a shipper in a programme, we derive a definition for imbalance: imbalance is the difference – on an hourly basis – between the damping in the programme and the difference between the entry and exit actually realised. For programmes without damping, planned entry and exit are equal, also on an hourly basis. In that case, the imbalance is the difference between the near-real time entry and exit allocations.

The programmes (and consequently, the damping) are fixed the day before the actual day of transportation.

Depending on the type of entry and exit points in a portfolio, in practice “near-real time” means “with a delay of approximately 5 minutes”. Using the near-real time allocations, we calculate the final near-real time imbalance for each portfolio every hour (if a portfolio consists of an entry and an exit programme, the net imbalance is calculated). The hourly imbalance is added to the POS of the previous hour to calculate the POS for this hour. When all the POSs have been calculated, the SBS is calculated as the sum of all POSs.

The POS will become final approximately 20 minutes after the hour. During the hour, we calculate the expected SBS every 5 minutes on the basis of the expected POSs for the end of that hour. The expected SBS is used to determine if a balancing action should be started on the ICE Endex Gas Exchange.

View all frequently asked questions

FAQ

  • The accountable POS will, apart from in exceptional situations, indeed be published between xx:15 and xx:20. The reason for this is that the near real-time allocations of the CSS are only available at xx:13. This is because actual near real-time allocations are used for determining the accountable POS and not the allocation from a previous hour as was the case for the determining the forecast POS.

  • The accountable POS is indeed only available between xx:15 and xx:20.
    For a POS where no near real-time allocations are needed that are only available after 5 minutes past the hour (such as RNB/PNB,TTF-B, etc.), the prognosticated POS for xx:00 (which is available before xx:05) is equal to the accountable POS at xx:15 – xx:20.

  • Yes, multiple portfolios with multiple POSses. A POS is per portfolio.

  • No, GTS has only a prognosis value for the coming hour.

  • Yes, a separate download has been provided for the zones (which indicates zones for one or more gas days). It is correct that in the SBS download, this zone info only shows the applicable zone. The specs for the separate zone message are given under the message specifications on the website (GTS_InformationServices_R1).