Publication of the report submitted by IPTO and approved by RAEWW on monitoring the margin of capacity available for cross-zonal trade for the year 20

(9)of the Regulation, the National Regulatory Authorities (NRAs) may grant a derogation from the provision of the minimum level of capacity, on foreseeable grounds where necessary, for maintaining operational security. In the case of the border between Greece and Bulgaria, the Regulatory Authority has already granted a derogation to IPTO for the years 2020, 2021, 2022 and 2023 for the reasons analytically presented in the relevant decisions. For the border between Greece and Italy, there has been no need for granting a relevant derogation to the TSO since the full thermal capacity (500 MW) of the GR-IT interconnection (DC link) is usually offered to the market, complying this way with the minimum 70% target. In July of 2019, ACER issued Recommendation 01/2019 detailing a methodology for the computation of the level of cross-zonal capacity to be made available for cross-zonal trade. Based on the criteria included in the Recommendation, ACER has published three reports on the result of monitoring the margin available for cross-zonal electricity trade in the EU in the years 2020 (part a and b), 2021 and 2022, respectively, and pointing out whether this is consistent or not with the 70% requirement. According to the provisions of Article 59 of Directive (EU) 2019/944 the effective compliance of each TSO with the 70% rule is the responsibility of the competent NRA. To this effect, IPTO has submitted to RAEWW its report on monitoring the margin of capacity available for cross-zonal trade for 2022 at the bidding zone borders of Greece with other EU-Member States (Italy and Bulgaria), based on computational results provided by ACER. After careful evaluation, RAEWW considered that the above-mentioned report for 2022 is sufficient for monitoring the level of capacity available for cross-zonal trade at the bidding zone borders of Greece-Bulgaria and Greece-Italy and for the effective compliance of IPTO with the 70% rule and approved the relevant report. Attached file: 1) IPTO’s report on monitoring the margin of capacity available for cross-zonal trade for 2022 MONITORING THE MARGIN OF CAPACITY AVAILABLE FOR CROSS-ZONAL TRADE FOR 2022 October 2023 Table of Contents Chapter 1: Introduction ........................................................................... 2 Chapter 2: Methodology for the compliance assessment ........................ 3 Chapter 3: GR-BG border ......................................................................... 5 Chapter 4: GR-IT border .......................................................................... 14 Chapter 5: Conclusions and further actions ............................................ 15 1 Chapter 1: Introduction In 2019, Regulation (EU) 2019/943 set new measures for electricity markets. One goal of the reform was to make sufficient capacity or Margin Available for Cross-Zonal Trade (MACZT). The associated measure, so called “minimum 70% target”, applies since January 1st, 2020 and requires Transmission System Operators (TSOs) to offer 70% of MACZT. Upon request of the TSOs, the National Regulatory Authorities (NRAs) may grant a derogation from the provision of the minimum level of capacity, on foreseeable grounds where necessary, for maintaining operational security. Moreover, Member States may adopt transitory measures through an action plan to cope with structural congestions. When an action plan is in place, the minimum level of capacity (70%) should be reached by 31 December 2025, while in the meantime, a linear trajectory should be matched. On the verge of the entry into force of the 70% rule, in July 2019, ACER issued Recommendation 01/2019 (hereinafter: the ACER Recommendation) detailing a methodology for the computation of the level of cross-zonal capacity to be made available for cross-zonal trade. Based on the criteria reported in the Recommendation, ACER published reports for the years 2020, 2021 and 2022, presenting the level of cross-zonal capacity offered on each border and pointing out whether this level is consistent or not with the 70% requirement. ACER reports have nonetheless only a monitoring scope, since assessing the effective compliance of each TSO with the 70% rule is the responsibility of the competent NRA. With this report, IPTO presents its assessment of the status of the 70% rule in 2022 on its EU borders with Italy and Bulgaria. This report is based on computational results provided by ACER. Chapter 2 describes how compliance with the 70% rule is assessed in a coordinated net transmission capacity (hereinafter: cNTC) environment. Chapter 3 is devoted to the GreekBulgaria border, while Chapter 4 focuses on the Greek-Italian border. Chapter 5 reports the conclusions. 2 Chapter 2: Methodology for the Compliance Assessment Following numerous interactions with the European Commission (EC), the European Network of Transmission System Operators for Electricity (ENTSO-E), NRAs and TSOs, ACER issued a Recommendation to ensure a consistent approach to the calculation and monitoring of the MACZT, and to support legal compliance enforcement. The main principles of the calculation are:

1. The MACZT is monitored for the limiting Critical Network Element and Contingency (CNEC).
2. The MACZT is the sum of the Margin made available within Coordinated Capacity Calculation (MCCC), and the flow induced by cross-zonal exchanges beyond coordinated capacity calculation – the Margin from Non-Coordinated Capacity Calculation (MNCC). ACER recommends computing the Margin Available for Cross-Zonal Trade (𝑀𝐴𝐶ZT) within a coordination area using the following equation for each CNECi, timeframe and timestamp (CC MTU): 𝑀𝐴𝐶𝑍𝑇𝑖 = 𝑀𝐶𝐶𝐶𝑖 +𝑀N𝐶𝐶𝑖 The estimated MACZT focuses on the physical capacity offered for the long-term timeframes and the day-ahead timeframe.
3. The influence of flows on bidding-zone borders between EU and non-EU countries is monitored separately. 𝑀𝐶𝐶𝐶𝑖 is computed for each coordination area, i.e. for each set of borders on which the cross zonal capacity is computed in a coordinated manner. For cNTC areas, the following formula is applied: MCCC =  pPTDFb * NTC i i b b where: • pPTDF bi is the positive PTDF of CNEC i in the direction associated to border b • 𝑁𝑇𝐶 b is the net transfer capacity computed in the capacity calculation process for border b for the considered timeframe; • the sum is extended to all the borders within the coordination area. In both flow based and cNTC areas, 𝑀𝑁𝐶𝐶𝑖 is computed by multiplying the corresponding zone related PTDF with the net position associated to the bidding zones in the common grid 3 model used for the relevant capacity calculation; before the computation the net position is adjusted in order to filter out the exchanges within the coordination area that are taken into account in the MCCC. To calculate MACZT as the sum of MCCC and MNCC, the concept of coordination areas is used. It describes the sets of bidding-zone borders within which capacity calculation is performed. For the Greek TSO one national coordination area is the North Greek borders, which include the TSOs of Albania, North Macedonia, Bulgaria and Turkey, because the flows as well as the exchange programs at the north Greek borders are independent, so the calculation for the total Greek imports/exports is managed initially and for each border afterwards. In case of borders consisting only of HVDC, the computation can be simplified: since the flows on HVDC are usually fully controllable, 𝑀𝑁𝐶𝐶𝑖 is equal to zero (i.e. no flows on the HVDC due to exchange outside the coordination area) and 𝑀𝐶𝐶𝐶𝑖 is equal to the 𝑁𝑇𝐶𝑏 on the considered border. The cNTC compliance with the 70% rule can be assessed by ensuring that the limiting CNEC has a margin equal to 70% in the original computation or by an adjustment of the original value of cross-zonal capacity, in case no limiting CNEC matches the 70% rule at the end of the cNTC calculation process. In that case, it is enough to evaluate the minimum increase of crosszonal capacity looking at the limiting CNEC. Besides CNECs, TSOs may introduce additional so-called allocation constraints, which may further limit cross-zonal exchanges. These constraints are used by TSOs, when they are needed, to maintain the transmission system within operational security limits; most often these constraints cannot be transformed efficiently into a maximum flow allowed on individual CNECs. 4 Chapter 3: GR-BG border This section presents the results of the compliance for the bidding-zone border GR-BG. Capacity calculation may be coordinated for several borders within a country, forming a national coordination area. For IPTO, this includes the north Greek borders with Albania, North Macedonia, Bulgaria and Turkey, or the borders of IPTO-OST, IPTO-MEPSO, IPTO- ESO, IPTO-TEIAS, respectively. In view of the above, the figures that follow, show the percentage of hours for which the MACZT was above, or below, the minimum 70% target, for the North Greek capacity coordination area. At the Greek north borders the cNTC approach is used: the cross-zonal capacity has been computed on the entire Greek Northern borders by increasing/decreasing injections in Albania, North Macedonia, Bulgaria and Turkey and by decreasing/increasing injections in Greece. The capacity calculation methodology applied is the SEE CCM, which has been in force since July
4. Data used for calculations To enable the monitoring of the MACZT on AC borders, ACER requested TSOs to provide the following data: -the description of their coordination areas (i.e. the bidding-zone borders on which a coordinated capacity calculation applies) -the list of all CNECs (for flow-based coordination areas) or at least the limiting CNECs per direction and coordination area (for NTC-based countries), for all hours, and the Fmax of each CNEC (Fmax is the maximum admissible flow on critical network elements, respecting operational security limits) -either: the PTDFs on all relevant borders; or at least one representative merged grid model and the grid model identifiers of the CNECs in the merged grid model, to allow ACER to calculate the PTDFs. The PTDFs describe the impact of a commercial exchange between two bidding-zones on a CNEC. -when and where relevant: the allocation constraints applied by TSOs, if any -the offered capacity (NTC values) calculated by the TSO, before consolidation with the neighboring country (i.e. before taking the minimum of the two TSOs’ values); -the TSO’s forecasts of cross-zonal exchanges between countries at the time of capacity calculation. TSOs were offered the possibility to perform themselves, partially or fully, the calculations of the MACZT and to provide the intermediate and/or final results to ACER. In this case, ACER 5 required that the underlying calculations be performed in line with the Recommendation. ACER evaluated both the quality of the data and the alignment of TSOs’ calculation with the Recommendation. IPTO provided ACER with the list of the limiting CNECs per direction for the coordination area of North Greek borders, for all hours and the Fmax of each CNEC. For all calculations, the offered capacity (NTC values) calculated by IPTO, before consolidation with the neighboring country (i.e. before taking the minimum of the two TSOs’ values when capacity is calculated unilaterally) was used. IPTO is not using any allocation constraints, so no results from such parameters which limit cross border exchanges are presented. ACER provided IPTO with the MCCC and MNCC values for each limiting CNEC with and without third countries. 2022 status For the year 2022, the cross-zonal capacity was computed based on a CACM-compliant methodology but without considering the 70% requirement due to the non-compliance of the current SEE CCM with the 70% rule and the lack of agreements with neighboring third countries. The impact of considering or not the exchanges with third countries may be significant, in particular for countries bordering with non-EU countries. The figures that are presented in the report highlight that this impact is particularly noticeable for Greece, bordering with Albania, North Macedonia and Turkey. All figures presented below are based on the results provided by ACER in May
5. Figures 1 and 2 below illustrate the percentage of the time when the minimum 70% target was reached not considering third countries and considering third countries for each direction (BG-GR and GR-BG) and totally for both directions, also showing the time where the limiting CNEC was not in Greece and when there was a failure in the process. 6 Figure
6. Percentage of the time when the minimum 70% target was reached for each direction - 2022 7 Figure
7. Percentage of the time when the minimum 70% target was reached in total for both directions - 2022 8 Figures 3 and 4 below illustrate the average margin available on elements where the minimum 70% target is not reached, not considering (top) and considering (bottom) exchanges with third countries for 2022 per direction (GR-BG and BG-GR) and in total. Figure
8. Average margin available on elements where the minimum 70% target is not reached for each direction 2022 9 Figure
9. Average margin available on elements where the minimum 70% target is not reached in total for both directions - 2022 10 Figure 5 below illustrate the share of CNECs with positive and negative MNCC as a % of all CNECs and respective average levels of MNCC as a % of Fmax, not considering and considering exchanges with third countries per direction (GR-BG and BG-GR). Figure
10. Share of CNECs with positive and negative MNCC as a % of all CNECs and respective average levels of MNCC as a % of Fmax - 2022 (% of CNECS) 11 Compliance with the 2022 derogation IPTO has been granted a derogation for 2022, in which the minimum target was set to 15% of MCCC. The target for 2022 was met at 97% of all cases (imports and exports). For the remaining 3%, the deviation from the minimum target can be explained by the big flows from the noncoordinated area (MNCC). The above big flows of MNCC are considered from experience as nonrealistic. According to the results of 2022, the 95th percentile of MNCC is equal to -220 MW. That means that for the rest 5% of the cases the values are considered as non-realistic, on these cases MNCC was less than -220 MW and even as low as -1700 MW. One possible explanation for the extremely low MNCC values are tool malfunctions. Chapter 4: GR-IT border Italy – Greece border belongs to GRIT CCR that implements a capacity calculation process based on a cNTC approach. Since the GR-IT interconnection consists of a DC link, the computation is simplified and the full thermal capacity (500 MW) is usually offered to the market, except when there is the need to reduce the flows because of congestions in the AC networks in Italy and/or in Greece. In 2022 the thermal capacity of the cable was almost always offered to the market whenever the cable was available for operation, except for a very few cases where reductions were made for system security reasons . It should be addressed that the Capacity Calculation methodology for the GR-IT CCR (in force since July 2021), incorporates the 70% rule, reassuring that the minimum margin is always achieved. Figure 6 below illustrates the percentage of the time when the minimum 70% target was reached on the DC GR-IT border, showing the time where the DC cable was out of service. 12 Figure
11. Percentage of the time when the minimum 70% target was reached on the DC GR-IT border – 2022 13 Chapter 5: Conclusions and further actions As it is illustrated in Chapter 4, for 2022, IPTO almost reached 100% compliance on the Italy – Greece border. Thus, regarding the GR-IT CCR, no derogation applies because the 70% requirement is fulfilled. Since July 2021 the new GRIT capacity calculation methodology for the day ahead and intraday timeframe is in operation and guaranties that the 70% rule is always considered. For the BG-GR border, the 70% requirement is not currently reached most of the time as illustrated in Chapter
12. Thus, a derogation applied in 2022 and was further requested for
13. Regarding the justifications underlying this derogation, three main reasons are mentioned: • Absence of consideration of third countries flows, • Insufficient potential for remedial actions and • Development of new processes and/or IT tools However, as Figure 2 illustrates in Chapter 3, with the consideration of third countries, for both directions, on the 55% of all timestamps where MACZT was calculated, the 70% requirement was fulfilled. Low MACZT values appear when third countries are not considered. In that case, three out of four North Greek borders are not included in the calculations. The European Commission recommended that the flows from a given third country are considered for the calculation of the MACZT if an agreement, in line with EU capacity calculation principles and rules, with the third country has been concluded. According to the guidance provided by the DirectorateGeneral for Energy of the European Commission in a letter of 16 July 2019, consideration of third (i.e. non-EU member) country flows in capacity calculation and MACZT could be possible on the condition that an agreement has been concluded by all TSOs of a Capacity Calculation Region (CCR) with the TSO of the third country, approved by the respective regulatory authorities. The agreement should be fully in line with EU capacity calculation principles and rules and should cover at least: (i) consideration of internal third country constraints for intraEU capacity calculation, (ii) consideration of EU internal constraints for capacity calculation on the border with the third country, and (iii) cost-sharing of remedial actions. Apart from the inclusion of third country flows for the compliance with the 70% rule, the currently applied SEE CCM methodology must be amended. 14 Since the last quarter of 2022, SEE TSOs have submitted an amendment of the SEE CCM to the SEE NRAs for approval in order for the SEE CCM to be compatible with the 70% rule. After its approval, SEE TSOs will try to sign the relevant agreements with their non-EU neighboring TSOs including among others the adoption of the amended SEE CCM. By Decision 2022/03/MC-EnC, the Ministerial Council of the Energy Community incorporated a package comprising the latest EU electricity regulations in the Energy Community. This Decision is binding not only on the Contracting Parties, but also on the neighboring Member States. In this way, reciprocity between Contracting Parties and EU Member States is established. This is especially relevant in case of the terms, conditions and methodologies (TCM) for specific regions which include both Member States and Contracting Parties. Such a region is SEE, where Greece belongs. The adapted Regulations and Codes by the Decision, require transposition by the Contracting Parties to their national legislation until 31 December
14. This transposition will bind the Contracting Parties to the adopted Regulations. This is very important for IPTO since it will facilitate discussions with EnC TSOs in the SEE area in order to come up with common methodologies. Such a methodology could be the Coordinated Capacity Calculation Methodology that takes into consideration the minimum 70% target on the margin available for cross zonal trade. 15