stogit.it SAMPEI user interface Modifications in force from 1st november 2013 on – Withdrawal Phase

Introduction The following slides explain the main modifications to the SAMPEI user interface for the withdrawal phase in force from 1st november 2013 on, carried out accordingly to Aeeg resolutions 75,92 e 353 of Possibility, for each storage service and related storage stock, to make seasonal, monthly and daily nomination program Possibility to nominate/re- nominate for each storage service and related storage stock Possibility to select the flow direction (injection/withdrawal) Visualization of nomination cycles Volumes of PB Gas Possibility to allocate the sold/bought gas on each stock Report capacità disponibili Report of available capacities Form for gas stock allocation rule at 31° october 2013 Resolution 353/2013/R/GAS of 1st August 2013 Publications of the modifications done for the calculation of the withdrawal capacity Examples of withdrawal capacity calculation for the peak and uniform services Informations of withdrawal capacity cut 2GESCON

NOMINATION PLANNING OCTOBER/NOVEMBER Weekly planning execution from 28th to 31° october 2013 Nomination of gas day 1° november; capacity allocated on the different stocks Renomination of gas day 1° november; capacities allocated on the different stocks Seasonal planning execution Mandatory - Dead- line for seasonal planning execution Seasonal planning disabled 15th october th october st october th november st november th november 2013 Start of weekly nomination planning 3GESCON

SEASONAL/MONTHLY/WEEKLY PROGRAM Each User will split the nomination program on each stock 4GESCON

DAILY NOMINATION FOR DAY G Nomination Cycle C1 indicates nomination cycle at C2 indicates nominatin cycle at Select gas day of interest or from day a to day e 2.Click on «Cerca» 3.data window appears 4.Choose the flow direction ticking the check box 5.Insert the nomination values under the different stocks and click on «Salva» 5GESCON

RENOMINATION FOR DAY G 1.Select the gas day of interest 2.Click on ˝Cerca˝ 3.Data window appears 4.Choose the flow direction ticking on the check box 5.Insert the nomination values» under the different stocks and click on «Salva 6GESCON

BALANCING PLATFORM (PB) MANAGEMENT The values shown in column «Limite inseribile» in the injection phase indicate the residual free space in stock In case the user will not insert any value, the allocation in the different stocks will be done accordingly to the storage code rules Totale da ripartire 7GESCON

BALANCING PLATFORM (PB) MANAGEMENT The values shown in column «Limite inseribile» in the withdrawal phase indicate the residual gas in stock In case the user will not insert any value, the allocation in the different stocks will be done accordingly to the storage code rules Totale da ripartire 8GESCON

REPORT AVAILABLE CAPACITIES In this window the capacities of each stock are shown 9GESCON

COMMUNICATION OF STOCK ALLOCATION(only for injection 2013) The following communication will be published on the Stogit web site and shall be downloaded and filled in by each User who must indicate the allocation, in percentage terms, of the gas stock into the different services. The form must be sent within 31° October 2013 only by in pdf format to stogit- To be noticed that the infringment of the time deadline mentioned above will entitle Stogit to allocate the stock into the different service stocks accordingly with the priority order established by the Storage Code paragraph 6.3 up to the complete filling-in of the available space. 10GESCON

RESOLUTION 353 – 1 st AUGUST 2013 Provisions related to the storage service The Authority for Electricity and Gas (AEEG) on 1 st August 2013 has established that Stogit, from 1 st November 2013, must update weekly the maximum withdrawal volumes for the following week. Users who have withdrawn less volume than the optimal volume, will be allocated part of the withdrawal capacity made available by Stogit on its website. This capacity of the system will be, within the system’s constraints, the maximum withdrawal capacity available. 11GESCON

RESOLUTION 353 – 1 st AUGUST 2013 Calculation of the maximum weekly withdrawal volumes Month of November: monthly withdrawal volumes 600 MSmc = Gj Maximum weekly withdrawal volumes= Gj The additional withdrawal capacity is allocated to users proportionally to the difference, if positive, between their real gas stock and the optimal gas stock they should have on the basis of contractually defined performances. WeekWeekly volume GjResidual / surplus TOTAL WeekWeekly volume GjResidual / surplus TOTAL In this example the weekly available volume hasn’t been totally withdrawn ( ). The additional withdrawal capacity made available on the following week ( ) is not equal to the residual of the previous week ( ) because of system’s constraints. Optimal withdrawal volume Real withdrawal volume 12GESCON

WITHDRAWAL PHASE PUBLICATIONS 13GESCON Profili_utilizzo_fattori_adeguamento/Profili_utiliz_2013_2014/Explains_ab out_withdrawal_phase.pdf ive/Profili_utilizzo_fattori_adeguamento/Profili_utiliz_2013_2014/Stor age_MODULAZIONE.pdf

Calculation of Flat Service’s withdrawal capacity Stock filling 100% Contractual Space = Gj Contractual withdrawal capacity CE contr = (Space/150) = / 150 = Gj On 1/11/2013 the adjustment factor (FA) is equal to 1 (Gas stock / allocated space) FA = / = 1 CE available = CE contr * FA = * 1 = Gj Monthly withdrawal volume = CE available * days (November) = * 30 = Gj Gas Stock i = Gas Stock i-1 – November withdrawal volume = – = Gj 100% Daily Capacity Monthly withdrawal volume Contractual gas stock (G contr )Adjustment factor NOV DIC JAN FEB MAR (- 1000)1 14GESCON Optimal withdrawal volume

To calculate the withdrawal capacity from the month of December on it’s necessary to take into account the contractual gas stock data: FA = G i / G contr,i G i = real gas stock at the first gas day of month i G contr,i = contractual gas stock at the first gas day of month i 100% Daily Capacity Monthly withdrawal volume Contractual gas stock (G contr ) Adjustment factor NOV DIC JAN FEB MAR ( )1 80% Daily Capacity Monthly withdrawal volume Gas stock (G) Adjustment factor NOV ,80 DIC ,80 JAN ,80 FEB ,80 MAR (- 800)0,80 15GESCON Calculation of Flat Service’s withdrawal capacity Stock filling 80% Contractual Space = Gj Contractual withdrawal capacity CE contr = (Space/150) = / 150 = Gj On 1/11/2013 the adjustment factor (FA) is equal to (Gas stock / allocated space) FA = / = 0,8 CE available = CE contr * FA = * 0,8 = 800 Gj Monthly withdrawal volume = CE available * days (November) = 800 * 30 = Gj Gas Stock i = Gas Stock i-1 – November withdrawal volume = – = Gj Optimal withdrawal volume Real withdrawal volume

80% Daily Capacity Monthly withdrawal volume Gas stock (G) Adjustment factor NOV ,80 DIC ,80 JAN ,19 FEB ,19 MAR (-106)0,19 100% Daily Capacity Monthly withdrawal volume Contractual gas stock (G contr ) Adjustment factor NOV DIC JAN FEB MAR ( )1 50% Daily Capacity Monthly withdrawal volume Gas stock (G) Adjustment factor NOV ,50 DIC ,50 JAN ,77 FEB ,77 MAR (- 620)0,77 60% Daily Capacity Monthly withdrawal volume Gas stock (G) Adjustment factor NOV ,60 DIC ,60 JAN ,90 FEB ,90 MAR (-700)0,90 Example 1: withdrawal volume increase and resulting FA decrement Example 2: withdrawal volume decrement and resulting FA increase Example 3: null withdrawal volume and resulting FA increase Calculation of Flat Service’s withdrawal capacity EXAMPLE: Optimal withdrawal volume 16GESCON

100% Daily Capacity Monthly withdrawal volume Contractual gas stock (G contr ) Adjustment factor * Multiplicative coefficient NOV478, ,38 DIC781, ,62 JAN1.978, ,57 FEB1.285, ,02 MAR428, (0)10,34 * the moltiplicative coefficient is subject to revision during the thermal year in the face of changes in base assumptions Optimal withdrawal volume 17GESCON Calculation of Peak Service’s withdrawal capacity Stock filling 100% Contractual Space = Gj Minimum Contractual withdrawal capacity (Space/150) = / 150 = Gj Additional Contractual withdrawal capacity (Space/577) = / 577 = 260 Gj On 1/11/2013 the adjustment factor (FA) is equal to 1 (Gas stock / allocated space) FA = / = 1 CE available = (CE min + CE add ) * FA * multiplictive coeff. = * 1 * 0,38 = 479 Gj November withdrawal volume = CE available * days (November) = 479 * 30 = Gj Gas Stock i = Gas Stock i-1 – November withdrawal volume = – = Gj

100% Daily Capacity Monthly withdrawal volume Contractual gas stock (G contr ) Adjustment factor *Multiplicative coefficient NOV478, ,38 DIC781, ,62 JAN1.978, ,57 FEB1.285, ,02 MAR428, (0)10,34 * the multiplicative coefficient is subject to revision during the thermal year in the face of changes in base assumptions 80% Daily Capacity Monthly withdrawal volume Gas stock (G) Adjustment factor *Multiplicative coefficient NOV ,800,38 DIC ,800,62 JAN1.582, ,801,57 FEB ,801,02 MAR342, (0)0,800,34 18GESCON Calculation of Peak Service’s withdrawal capacity Stock filling 80% Contractual Space = Gj Minimum Contractual withdrawal capacity (Space/150) = / 150 = Gj Additional Contractual withdrawal capacity (Space/577) = / 577 = 260 Gj On 1/11/2013 the adjustment factor (FA) is equal to (Gas stock / allocated space) FA = / = 0,8 CE available = (CE min + CE add ) * FA * multiplictive coeff. = * 0,8 * 0,38 = 383 Gj November withdrawal volume = CE available * days (November) = 383 * 30 = Gj Gas Stock i = Gas Stock i-1 – November withdrawal volume = – = Gj Optimal withdrawal volume Real withdrawal volume

100% Daily Capacity Monthly withdrawal volume Contractual gas stock (G contr ) FA *Multiplicative coefficient NOV478, ,38 DIC781, ,62 JAN1.978, ,57 FEB1.285, ,02 MAR428, (0)10,34 80% Daily Capacity Monthly withdrawal volume Gas Stock (G)FA *Multiplicative coefficient NOV ,80 0,38 DIC ,44 0,62 JAN791, ,44 1,57 FEB565, ,44 1,02 MAR188, (-149)0,44 0,34 60% Daily Capacity Monthly withdrawal volume Gas Stock (G)FA *Multiplicative coefficient NOV 287, ,60 0,38 DIC 468, ,60 0,62 JAN 1.186, ,94 1,57 FEB 1.201, ,94 1,02 MAR 400, (0)0,94 0,34 50% Daily Capacity Monthly withdrawal volume Gas Stock (G) FA *Multiplicative coefficient NOV 239, ,50 0,38 DIC 390, ,50 0,62 JAN 989, ,57 FEB 1285, ,02 MAR 428, (0)1 0,34 Optimal withdrawal volume 19GESCON Calculation of Flat Service’s withdrawal capacity Example 1: withdrawal volume increase and resulting FA decrement Example 2: withdrawal volume decrement and resulting FA increase Example 3: null withdrawal volume and resulting FA increase

The distribution will be done accordingly to the priority of stocks as indicated in the Storage Code (§ 6.3.7) Ratio between volume withdrawn per each user and total volume withdrawn of all cutted users The volume withdrawn by each user (those who have an higher % withdrawn will have an higher cut) THE FOLLOWING ELEMENTS ARE TAKEN INTO ACCOUNT FOR THE CUT: The difference between available capacity and nomination per each service When the sum of nominations exceeds the total available capacity of all users CAPACITY CUT: WITHDRAWAL CAPACITY CUT 20GESCON