ENTSOG Tariff NC - Implementation Document 2nd Edition

Approaches other than allowed for capacity weighted distance reference price methodology

Average pipeline distance In general, pipeline distance is the distance along a defined pipeline. If two or more pipelines with different lengths connect the same entry and exit point, then it is possible to calculate alternative distances; one can determine both the shortest distance and the average. The calculation of average distance could require a large amount of data, since a TSO’s networks often contains many entry and exit points. It can be useful to simplify the representation of the network to simplify the calculation of average distances. Airline distance The airline distance is the result of computations that apply the Pythagorean Theorem to coordinates assigned to each point. Airline distance is analogous to using a ruler to measure the distance between two points on a flat map. The logic of the calculation is: (a) to assign coordinates to each point: easting and northing; and (b) to apply the following formula:

Where: Distance (En,Ex)

distance between the entry point and the exit point in km;

East En

, East Ex

easting of the entry or exit point according to the projected coordinate system; northing of the entry or exit point according to the projected coordinate system.

North En

, North Ex

Assuming a flat surface implies an approximation only, whose accuracy may be sufficient depending on terrain topography. Airline distance does not consider the extra length of detours that uneven terrain may require, and does not consider differences in altitude. There are two ways to calculate airline distance: \\ The Universal Transverse Mercator projected coordinate system (UTM), intro- duced across Europe; \\ Geo Information System (GIS), software normally available to TSOs, which allows for the calculation of distance independent of the coordinate system used.

North in km

Entry point: North: 41 km East: 30 km

Airline distance: √ (41–37) 2  + (30–33) 2  = 5

Exit point: North: 37 km East: 33 km

East in km

Figure 17: Simple example of airline distance calculation

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