ENTSOG TYNDP 2017 - Main Report

2.2.2 SEASONAL AND PEAK CONSUMPTIONS

2.2.2.1 Seasonal

The gas transmission network experiences different seasonal demand levels driven largely by the climate and heating requirements, the variation seen is represented in figure 2.8. Although October is seen as a winter month in the gas year, it is typically a storage injection month. In order to capture the seasonality of the gas market in the over-the- whole-year simulation, average demand levels for summer and winter days are based on the storage injection and withdrawal periods, more details on this method- ology can be found in Annex C4.

35,000 GWh/d

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0

Jan 09 July 09 Jan 10 July 10 Jan 11 July 11 Jan 12 July 12

Jan 13

July 13

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July 14 Jan 15 July 15 Jan 16

Winter

Summer

October

Figure 2.8: Yearly modulation

2.2.2.2 Peak day and highest 14-day period by year

The day of highest consumption in the year is a key input of the network design process and represents one of the most stressful situations to be covered by the gas transmission system. The design and operation of a system is also challenged by the availability of supply sources during periods of high consumption. On this basis, ENTSOG has considered both the peak day and the highest 14-day demand period as significant for testing the resilience needs of the system  1) . However as table 2.1 shows from the last seven winters at EU aggregated level, the highest daily consumption can often occur outside of the highest 14-days average consumption

 1) Please note that for the TYNDP assessment this corresponds to the National TSO Design Case and highest 14-day demand relates to a 1-in-20 year situation

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Ten-Year Network Development Plan 2017 Main Report