ENTSOG TYNDP 2017 - Main Report

6.3.2.4 N-1 for ESW-CBA infrastructure assessment

The section covers the results for the N-1 for ESW-CBA indicator, as calculated un- der the CBA methodology (N-1 for ESW-CBA). This capacity-based indicator  1) is cal- culated for each country. It is intended to measure if countries would have the nec- essary capacities to cover their peak demand, even in the case that the single largest infrastructure would be unavailable. The indicator is expressed as the percentage of the peak demand that remaining capacities allow to cover. The indicator derives from Regulation (EC) 994/2010 on Security of Supply, but shows some differences with the N-1 for ESW-CBA indicator calculated by Compe- tent Authorities. Indeed, it is computed over the whole TYNDP time horizon and is established based on the capacities used in the TYNDP: for interconnection points where the reported capacities are not the same on both sides of the border, the cal- culation is done with the lower capacity (lesser-of-rule). Additionally, it is calculated considering nominal withdrawal capacities for storages, whereas the actual with- drawal capacities depend on the inventory level. Interconnectors that are located in one given country but cannot contribute to the demand of the country are not in- cluded in the N-1 for ESW-CBA indicator calculation for this country. Figure 6.7 shows the assessment results for the N-1 for ESW-CBA indicator in the Blue Transition and EU Green Revolution scenario for the years 2020 and 2030. The low infrastructure level allows most countries to deal with unavailability of the largest infrastructure during high demand situations. Some needs can be identified in Bosnia and Herzegovina, Croatia, Estonia, Finland, FYROM, Greece, Ireland, Luxemburg, Portugal, Romania, Slovenia and Sweden. Bulgaria in 2017 and Denmark and Poland in the Blue Transition scenario in the later years also show some needs. The appearance of needs for Lithuania in 2030 relates, as mentioned earlier in the chapter, to the Klaipėda LNG FSRU not being considered anymore in the low infrastructure level from 2025, reflecting the expiration of the FSRU leasing agreement. For those poorly connected countries where the N-1 for ESW-CBA indicator is not only below 100% but very low (Finland close to 0%, but also Sweden or Ireland) or where the demand is highly variable (possibly related to the role of gas in the power sector) a N-1 for ESW-CBA situation can induce demand disruption for demand lev- els well below and/or for occurrences much more frequent than those of the peak demand. Finally, the indicator may picture a too optimistic situation as it assumes that transmission and withdrawal capacities can be fully used, which may not be the case in case of upstream bottleneck or if storages are already partly empty.

 1) It is based on capacities (which are an input to the TYNDP modelling) and not on outputs of the modelling.

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Ten-Year Network Development Plan 2017 Main Report