The GTS network must always be in balance; that is the reason why entry and exit volumes always have to be in balance. The rules set out on the Balancing regime web pages explain how GTS keeps its network in balance. Please take into account that when your programme is not balanced, this may have severe financial consequences.
A market-based balancing regime
This webpage describes in broad lines the current balancing regime and market model which came into effect on 1 April 2011 and underwent some changes on 3 June 2014 to comply with the European Network Code.
The gas transport network must be in balance so that gas can be transported safely and effectively. ‘In balance’ means that the transport network remains at the correct pressure and that the overall volume of gas removed from the network matches the volume entering it.
Each market party is responsible for the quantity of gas it removes or feeds in, which means that the market parties also share responsibility for maintaining the balance of the transport network. Parties know their own position (POS) at all times and are in that way able to contribute in keeping the transport network in balance. In addition, the balance situation of the total national network, or the sum of the positions of all parties, is publicly accessible at any time.
While the position of the total network remains within the permitted limits (dark green zone), the transport network is in balance and none of the parties needs to take any action. If the total transport network gets out of balance, market parties can intervene themselves by feeding gas into the transport network or removing gas from it. If this action is inadequate and the imbalance gets too big, a market-focused correction mechanism comes into play and we, the national network operator, buy additional gas or sell gas. The parties which cause the imbalance, pay the costs of the gas needed to resolve the imbalance.
How does this work in practice and in more detail?
Before the start of the gas day, shippers send GTS a programme showing their predicted hourly entries, exits and TTF deals for the following day. Shippers which supply small-scale users apply a damping formula to the programme, allowing them to feed in gas according to a pattern that is comparable to the pattern that is damped in the exit programme.
During the gas day, we compare this programme with the actual allocation on the basis of near-real-time data in order to determine the imbalances in the portfolios. The imbalances calculated for each portfolio are added up and divided with the parties on an individual basis via the imbalance signal in the portfolio (Portfolio Imbalance Signal, POS). The total of all individual POSs is called the System Balance Signal (SBS) and is published on the same timescale as the POS.
We monitor the SBS and take corrective action if necessary. If the SBS is not zero, this points to an imbalance in the system. The imbalance area is divided into zones. If the SBS is in the dark green zone, no balancing action is required. But if the SBS is in the light green, orange or red zone, a correction mechanism is triggered and gas is bought or sold on the within-day market of ICE Endex. We refer to this as a Within-Day Balancing Action (WDBA).
This balancing regime does not have a specific balancing period. Having a short or long position in a portfolio may not have any consequences for some time, provided that the SBS remains in the dark green zone.
If you would like to know more about specific parts of the balancing regime, go to:
- POS and SBS
- Within Day Balancing Action (WDBA)
- Offline settlement
- Linepack Flexibility Services
Would you like to read the complete terms and conditions? The balancing regime is described in the Transmission Code Gas TSO.
Q & A
It is impossible to estimate in advance. We look 10 minutes and 15 minutes past the hour to the end of hour prediction of the SBS. If the prediction of the SBS at 10 minutes past the hour gives a reason to a WDBA, then an announcement is made in Gasport and a Request For Quote (RFQ) is placed on the trading screen of the ICE Endex. The announcement and the RFQ is an estimate of the volume and product placed on the within-day market of ICE Endex and is based on the latest information.
If the prediction of the SBS at 15 minutes past the hour still gives a reason to a WDBA, then an update of the announcement is made and again a Request For Quote (RFQ) is placed on the trading screen of ICE Endex.
If the prediction of the SBS for the next hour at 21 minutes past the hour gives a reason for a WBDA than an order is placed on the within-day market of ICE Endex.
The type of product for which the order is placed, is dependent on the color of the zone wherein the SBS is predicted. In the light green zone GTS send an order for a WD product to the exchange with a lead time of 2 hours and 40 minutes with supplies for the remaining hours of the gas day. As an indication, an order that leads to a transaction at 12:21 will be delivered from 16:00 to 06:00. In the orange and red zone GTS send an order for a Next-Hour product with a lead time of 40 minutes. The whole delivery takes place in one clock hour. An order for a Next Hour product that leads to a transaction at 12:21 has a delivery from 13:00 to 14:00.
We disclose the size of the zones per hour, based on the estimated transport load (with regard to the programmes delivered by the Shippers), at least two hours before the beginning of the gas day. These hourly values will not be changed after they have been published.
No, you are only obliged to apply damping if you transport gas to exit points that deliver to domestic consumers.
The volume that must be called will be calculated as follows:
- Difference between the anticipated final value of the SBS and the boundary value of the dark green zone.
- The part that possibly is not yet delivered of a realized WDBA transaction is included in the determination of the volume of any new WDBA. This only applies for WDBA with the SBS in the light green area.
- If the SBS is in the light-green zone, and the imbalance is less than the unbalance of the previous hour, no WDBA will take place.
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.