ENTSOG Tariff NC - Implementation Document 2nd Edition

Example of non-zero distance calculation: distance D A,B between point A and point B is the shortest pipeline distance between these points which respects the flow scenario principle. It is not possible to connect A to B by flowing gas between N and D, because this section is a unidirectional pipe- line between production plant D and the bidirectional network at consumption point N (there is no distance from N to D identified as such in the distance table, while distance from D to N is positive). The next-shortest pipeline is the one via points H and P. Thus, distance between A and B is the sum of distances for sections A to N, N to H, H to P, and P to B. The table gives 20.5km for distance AB. The same cal- culations are performed for all the table. Considering the case of entry point A , the table indicates the following results: \\ Positive distances for points B, H, I, K, M, N, O, and P which may be connected with A because of the existence of a flow scenario. \\ Zero distance to some exit points due to the lack of a flow scenario for the following reasons: problem of unidirectional pipelines (points C and R), or no flow from and to the same point (point A). The following step (as per Article 8(2)(a)) is to calculate weighted average distances (WADs) for entry points (AD En ) and exit points (AD Ex ). The result of calculations also appears in Table 31  1) . No (further) clusters of points A to R are con- sidered here, for simplicity.

WADs FOR ENTRY POINTS

The formula for entry points in Article 8 is as follows.

Distances D En

,E x have been calculated according to the shortest pipeline route

approach. It is important to note that, since some distances have been marked as ‘ 0 ’ because of the impossibility of a flow scenario between entry point P1 and exit point P2 , it is also necessary to mark as ‘ 0 ’ the forecasted contracted capacities at P2, otherwise WAD for P1 will be underestimated. The lack of a flow scenario between two points implies to amend both distances and capacities used for calculations. Therefore, for entry points, the following matrix of corrected exit forecasted contract- ed capacities is used for ADEn derivation, and it displays ‘ 0 ’ in red where applicable.

 1) As indicated in the previous footnote, it is important to notice that the value of D En,Ex tions at entry points and at exit points, due to the flow scenario constraint.

may be different for WAD calcula-

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TAR NC Implementation Document – Second Edition September 2017