Period to be considered: minimum of 37 years (from 1 January 1975 to 31 December 2011). For those TSOs having no access to sufficient historical weather/temperature data through their own sources, daily average temperatures coming from a Commission’s temperature database (average values by country and day) were used. Relevant daily temperatures to be considered: yearly minimum effective temperatures by calendar year. 1-day Uniform Risk temperature defined by the percentile 0.05 of the relevant temperatures. It should be noted that not all TSOs have climatic demand models, meaning that it was not possible to apply the Uniform Risk Situations methodology perfectly. In addition, climatic conditions have a direct effect on the heating driven gas demand; nevertheless this link cannot be extrapolated to gas demand from the electricity sector. This sector in general doesn’t have a strong relationship with climatic conditions. Hence demand under the 1-day Uniform Risk Situation only provides harmonised definition for the gas demand. Moreover, in several not yet mature markets, the demand estimation depends not only on the climatic conditions assumptions but also on the assumptions regarding the penetration of gas in the various consumption sectors. Demand under 14-day Uniform Risk Situation A 14-day Uniform Risk Situation has been included in the analysis in order to capture the volume effect such duration may have on supply, especially with regard to UGS and LNG terminals. The 14-day demand levels are considered through the assessment of the last day of such a period. This last day is the most stressful moment as the supply availability from the storage (UGS and LNG) at this point may be undermined by high deliverability in the previous 13 days following the high consumptions. For consistency reasons, ENTSOG used the same statistical approach as for the 1-day Uniform Risk Demand Situation, replacing the effective temperatures by the 14-day average effective temperatures in the data set. The inclusion of two full weeks in the 14-day period doesn't take into account possible lower demand levels during weekends or holidays for the average demand on a 14-day period. As noted above, considering the decreasing deliverability of UGS and LNG terminals on the period, for a given level of demand, the last day is the most stressful one. As the volume of supply used over the period is independent from the demand profile, a flat average demand profile has been considered.
Period to be considered: minimum of 37 years (from 1 January 1975 to 31 December 2011). For those TSOs having no access to sufficient historical weather/temperature data through their own sources, daily average temperatures coming from a Commission’s temperature database (average values by country and day) were used. Relevant daily temperatures to be considered: yearly minimum effective temperatures by calendar year. 1-day Uniform Risk temperature defined by the percentile 0.05 of the relevant temperatures. It should be noted that not all TSOs have climatic demand models, meaning that it was not possible to apply the Uniform Risk Situations methodology perfectly. In addition, climatic conditions have a direct effect on the heating driven gas demand; nevertheless this link cannot be extrapolated to gas demand from the electricity sector. This sector in general doesn’t have a strong relationship with climatic conditions. Hence demand under the 1-day Uniform Risk Situation only provides harmonised definition for the gas demand. Moreover, in several not yet mature markets, the demand estimation depends not only on the climatic conditions assumptions but also on the assumptions regarding the penetration of gas in the various consumption sectors. Demand under 14-day Uniform Risk Situation A 14-day Uniform Risk Situation has been included in the analysis in order to capture the volume effect such duration may have on supply, especially with regard to UGS and LNG terminals. The 14-day demand levels are considered through the assessment of the last day of such a period. This last day is the most stressful moment as the supply availability from the storage (UGS and LNG) at this point may be undermined by high deliverability in the previous 13 days following the high consumptions. For consistency reasons, ENTSOG used the same statistical approach as for the 1-day Uniform Risk Demand Situation, replacing the effective temperatures by the 14-day average effective temperatures in the data set. The inclusion of two full weeks in the 14-day period doesn't take into account possible lower demand levels during weekends or holidays for the average demand on a 14-day period. As noted above, considering the decreasing deliverability of UGS and LNG terminals on the period, for a given level of demand, the last day is the most stressful one. As the volume of supply used over the period is independent from the demand profile, a flat average demand profile has been considered.
INV_130320_CBA-Methodology_InformalConsultation.docx