Plan for the Implementation of New Capacity and for Development of the Transportation Network

Snam Rete Gas

PLAN FOR THE IMPLEMENTATION OF NEW CAPACITY AND FOR DEVELOPMENT OF THE TRANSPORTATION NETWORK

Document prepared by Snam Rete Gas S.p.A. for compliance with the Delibera 137/02 of the Autorità per l’energia elettrica e il gas.

September 1st, 2004

Foreword

Snam Rete Gas S.p.A. publishes the plan for the implementation of new capacity and the development of its transportation network, prepared on the basis of currently available information and on the basis of relationships with its own clients, securing transparency and impartiality among users in conformity with provisions of Directive no. 98/30/EC of the European Parliament and of Law Decree no. 164/2000.

The present document has been prepared in compliance with the article 4 subsection 1 letter b, of Delibera no. 137/02 of the Autorità per l’energia elettrica e il gas.

The projects that figure in the programme result from studies carried out by Snam Rete Gas on the basis of its own forecasts of capacity requirements.

The infrastructure development plans included in this document are not binding for Snam Rete Gas that, therefore, reserves the right to modify them every time that new elements, such as for example evolutions of market requisites different from the current hypotheses, require it, as provided for in article 4 subsection 2 of Delibera no. 120/01 of the Autorità per l’energia elettrica e il gas.

Index

1 PLANNED INFRASTRUCTURES 1.1 Complete Programme 1.2 Transportation on the National Network 1.3 Transportation on the Regional Network 1.4 Main projects

2 PLAN OF CAPACITIES 2.1 Entry Points interconnected with foreign pipelines 2.2 Exit Points interconnected with foreign pipelines 2.3 Methodology for calculating capacities 2.4 Operational constraints and boundary conditions used for simulations 2.5 Interruptible capacities 2.6 Simulation Programs

3 ATTACHMENTS

1 PLANNED INFRASTRUCTURES

1.1 Complete programme

The plan for implementation of new capacity and for development of the transportation network includes projects whose construction is under way and those whose start is scheduled in future years, within the next four-year term. The planned investments after 2004 are the result of analysis and evaluations based on the information available at this moment. The implementation of these investments depends from the presence of appropriate conditions and, in any case, their planning is subjected to annual revisions that could introduce significant changes. In particular, it’s indicated the project relating to Dorsale Adriatica, that is conditioned on the commitments of capacity utilization at the entry point of the LNG terminal of Brindisi.

Furthermore Snam Rete Gas has planned to put out some sections of natural gas pipelines and some plants, which, in total, haven’t significant impact on the reliability of the network of natural gas pipelines, or on the availability of transportation capacity.

The development projects have been evaluated on the basis of transportation scenarios that reflect forecasts of consumptions of natural gas in Italy, relationships with subjects interested in starting-up new off-take points and those with users who use capacity in the inlet and outlet points. These projects represent approximately 80% of the plan and are characterised by the presence of significant works that will make it possible in the near future to inject quantities of gas onto the Italian network from the main pipelines supplying the Country. The remaining 20% of the plan includes different types of interventions including those aimed preserving existing infrastructures. Preservation projects have been identified on the basis of information available on the status of existing pipelines.

Works relating to Transportation on the National Network represent approximately 70% of the plan, the remaining 30% concerns the Regional Network.

In total the Snam Rete Gas plan provides for development of the network of gas pipelines from the 30,120 km operating at the end of 2003, to the 33,200 km at the completion of the planned projects.

Similarly, the increase of installed capacity in the Compressor stations is forecast in the plan from the current 625 MW (37 compressor units in 11 stations), up to approximately 820 MW in the four-year term (nine new units, included the two units installed in Minerbio station under way of acquisition). A further increase of approximately 80 MW (six new units installed in two new stations) is planned in the following years.

1.2 Transportation on the National Network

40% of the National Network Development Plan is composed of projects already being implemented or that will be started during 2004, while the remaining 60% are planned to start in the following years.

These infrastructures are destined mainly to reinforce the importation system, and will include the completion of works dedicated to importation from Russia, to pipeline Gela – Enna and those for connection from the LNG terminal of Panigaglia and the continuation of the activities related to the development of the pipelines system from the South. It’s under consideration the implementation of a new compressor station close to the distribution node of Poggio Renatico and moreover, if the capacity commitments of the future Entry Point of Brindisi LNG terminal, became concrete, the works related to the project “Dorsale Adriatica” will start. These works will be presented in detail in paragraph 1.4.

The remaining development projects are aimed at reinforcing other main national transportation pipelines and they are mainly located in the areas of Southern Piedmont and the North-East. These include works related to the Bosentino – Trento and Gagliano – Sparacollo natural gas pipeline and the developing of the connection to the storage of Collalto. Planned works for reinforcing the Mortara – Alessandria, Alessandria – Oviglio and Verona - Trento (section Vigasio - Bussolengo) natural gas pipelines have been started.

In total the plan will develop the National Network from approximately 7,990 km operating at the end of 2003, to approximately 9,280 km, at completion of planned projects. The compression system will be developed from the current 625 MW, distributed over 37 compressor units, to approximately 900 MW at completion of plan, resulting from the installation of 2 new station, from the installation of new units in existing stations and from the acquisition of the Minerbio station, for a total of 15 new units with 280 MW of new compression capacity.

1.3 Transportation on the Regional Network

70% of the National Network Development Plan is composed of projects already being implemented or that will be started during the current year, while the remaining 30% are planned to start in the following years.

These infrastructures are aimed at extending and reinforcing of the regional transportation network, for which is planned the completion of the Contursi – Battipaglia, Reinforcement of Bagnoli Connection (in Campania and Basilicata regions), Giarratana – Solarino (Sicily) and Brindisi- Arnesano (Apulia) natural gas pipelines and of the reinforcing of the connections for Abbadia Lariana (Lombardy). Moreover, have been started reinforcements in the area of Southern Piedmont (Oviglio – Ponti, Cherasco – Cuneo and Cosseria – Mallare natural gas pipelines), in Eastern Lombardy (Bergantino – San Giorgio di Mantova, Azzano Mella – Travagliato, Travagliato – Mornico al Serio, Mornico al Serio – Zanica) and in Umbria (Pietrafitta – Perugia natural gas pipeline). Moreover, have been planned, among the relevant projects, the natural gas pipelines: Lainate – Castellanza, Sergnano – Casirate (Lombardy) and Bondeno – Ferrara (Emilia Romagna). Furthermore, on the basis of relationships developed with the subjects interested in connecting their own sites to the transportation network, many connections of new thermoelectric power plants, of industrial plants and of distribution networks scattered in the eight territorial districts, have been identified. Some of these works have already started, meanwhile for the remaining ones, for which to date no defined contractual agreements exist, actual planning and implementation is subject to confirmation of interest by the requesting subjects and to the subsequent conclusion of agreements for connection. Among about 70 connections started in 2004, 7 of them concern new thermoelectric plants with power of approximately 3,600 MW. The plan consist of implementation of approximately 80 connections in total per year. Among the connections under implementation, there are also the connections included in the plan of Methanization of the South.

In total the plan will develop the Regional Network of Snam Rete Gas from 22,130 Km operating at the end of 2003 to approximately 23,500 km, at the end of 2007, and an increase of approximately 300 km in the following years, with a total increase of approximately 1,700 Km.

1.4 Main projects

To complete the description of the plan, hereinafter are indicated the most significant infrastructures. These projects represent approximately 60% of the total and they are related to the implementation of works distributed all along the Snam Rete Gas transportation network.

1.4.1 Additional Importation from Russia The project consists in laying approximately 190 Km of DN1200 pipeline and 43 km of DN1400 pipeline (section Camisano-Zimella), parallel to existing DN900 and DN1050 lines between Tarvisio (UD) and Zimella (VR).

The planned works, 133 km of which are operating, will be completed within the year 2007, thus allowing for an increase in importation capacity from Russia and from Slovenia, at the entry points of Tarvisio and Gorizia, up to 105 Mm3/day on the whole.

1.4.2 Gela – Enna natural gas pipeline The project consists in implementing a natural gas pipeline 67 km long and diameter DN900, which connects the landing point of the sealine, located in Sicily in the vicinity of Gela, to the Transmed natural gas pipeline at the level of the compressor station of Enna.

This project, that will be operating at the beginning of the Thermal Year 2004-2005, together with the “Transmed Reinforcement” initiative, allows to fulfil the capacity requirements related to importation from Libya, that amount at the moment to about 25 MSm3/day at the end of the build-up. The new pipeline, connected to implementation of the Giarratana-Solarino natural gas pipeline, allows for closure of network ring operating for supply of the area of South-Eastern Sicily.

1.4.3 Reinforcement of Transmed During the year 2002, SNAM Rete Gas launched investments necessary for implementing works to reinforce the backbone importation network consisting of: ◊ Implementation of a 3rd line (DN1200) with a total of approximately 290 km in the Enna-Montalbano, Palmi-Martirano, Campochiaro- Sulmona sections; ◊ Reinforcement of the existing stations of Messina, Tarsia, Montesano, Melizzano, Gallese, Terranuova by means of the addition of new compressor units; ◊ Adjustment of piping and auxiliary plants in the existing stations.

Commissioning of these works is planned within the year 2006; they will provide 86 MSm3/day at the entry point of Mazara del Vallo and the already mentioned 25 MSm3/day at the entry point of Gela.

1.4.4 Pontremoli – Parma natural gas pipeline The project involves the laying of approximately 70 Km of pipeline DN750 between the site of Pontremoli and Parma. The above-mentioned work will be operating at the beginning of the Thermal Year 2004-2005 and will form a new connection of the LNG terminal at Panigaglia to the National Network. The natural gas pipeline will be laid alongside the existing section of Cortemaggiore – La Spezia, which follows a different line, thus increasing total capacity for disposal of the regassified gas at Panigaglia to 13 Mm3/day.

1.4.5 Compressor station of Poggio Renatico The project is at the study stage and involves the implementation of a new compressor station in the vicinity of the distribution node of Poggio Renatico (FE), that is placed about 20 Km far away from the distribution node of Minerbio (BO). It will allow for compression of increasing volumes of gas coming from the importation pipelines from Russia and from North Africa, together with foreseen volumes from new LNG terminal projects, that converge in the area of Minerbio. The implementation of this station will depend on the development of capacity plans of the above-mentioned transportation lines.

1.4.6 Compressor station of Minerbio The project concerns the compressor station placed close to the node of Minerbio (BO). It consists of the acquisition of two compressor units with 10 MW, used for transportation; moreover, it also consists of the implementation of the works on the plants, that are needed to make these turbines fully independent from the existing plants, and of the updating of the turbines to the latest technology of pollution emission control.

1.4.7 Dorsale Adriatica The project consists of reinforcing the importation lines from South by means of the implementation of a new DN1200 line about 680 km long and of a new compressor station (Sulmona) with a power of 33 MW. The route of the pipeline is placed on a new line at the eastern side of Transmed towards the Adriatic sea. The new pipeline will connect the existing Montesano – Brindisi pipeline from Massafra (TA) to the node of Minerbio (BO). The new pipeline will connect to the Transmed pipeline in the section Campochiaro – Sulmona, at the end of which the new compressor station will be placed.

The new line can transport about 30 MSm3/day, enough for capacity requirements related to planned LNG terminal, placed near Brindisi. Activities begun in 2004 consist of planning and public permissions, whereas implementation will start only if there will be the agreements about the utilization of the new entry capacity.

1.4.8 Giarratana - Solarino natural gas pipeline The project consists of laying 38 km of DN600 diameter pipeline and completes a ring structure to supply the market of the south-est of Sicily. Commissioning of this work is planned within the year 2005 and will allow an increase of redelivery pressures to users, and a development of consumptions estimated at 3 Mm3/day at least in this area.

The natural gas pipeline will also enable possible connections of some municipalities not yet connected to the transportation structure.

1.4.9 Reinforcement of the South-West Piedmont Network The reinforcement consists of implementation of five pipeline, two of them, DN750 diameter, belonging to national network (Mortara – Alessandria 45 km long and Alessandria – Oviglio 12 km long natural gas pipeline) and three of them to regional network (Oviglio – Ponti 38 km long and DN750 diameter, Cherasco – Cuneo 37 km long and DN500 diameter and Cosseria – Mallare 17 km long and DN500 diameter natural gas pipeline).

These projects develop the existing transportation pipelines that supply South-West Piedmont and Liguria also for the future development of thermoelectric sector near Savona. Moreover the above projects permit, by means of the modification of the configuration of the Piedmont national network pipeline, to increase the transportation capacity at the Passo Gries Entry Point.

1.4.10 Bergantino- S. Giorgio di Mantova pipeline The project consists of a pipeline 36 km long and diameter DN750, with planned commissioning in February 2008. This project allows to adapt the performance of the network to the new thermoelectric projects in Mantova area, preserving a pressure always higher than 35 bar at the redelivery points. Moreover, it forms an important mesh of the regional network because it connects the Mantova area to Zimella – Minerbio line.

1.4.11 Reinforcement of the South-Eastern Lombardy Regional Network The project consists of laying three regional network pipelines DN500 diameter, adjacent to each other (Mornico al Serio – Zanica started in 2003; Azzano Mella – Travagliato and Travagliato – Mornico al Serio, started in 2004), for a total length of 46 km. The commissioning is scheduled at the end of 2007. These works allow to develop the regional network structure in the province of Bergamo and Brescia and to improve the performance of the network to comply with the growing requirements of the market in these areas.

1.4.12 Pietrafitta – Perugia natural gas pipeline The project consists of laying a pipeline of about 25 km and DN400 diameter. The commissioning is planned in the summer of 2007.

The pipeline allows to create a mesh of the regional network of Umbria, developing the existing structure and connecting them to the Transmed pipeline. The reinforcement permits also to improve the performance of the above mentioned network, increasing reliability and operating flexibility.

2 PLAN OF CAPACITIES

2.3 Methodology for calculating capacity The Chapter 2 of the Network Code describes the performance of the Snam Rete Gas network; in particular there are the definitions of capacity, the method to determine it, a short description of simulation programs and technical and operational constraints and boundary conditions. For the purposes of Network Code duties, dimensioning and operating the system, and fulfilling the requirements of current legislation and the resolutions of the Autorità per l’energia elettrica e il gas, Snam Rete Gas carries out periodic analyses of its transportation system, aimed at establishing capacity.

The methodologies adopted from Snam Rete Gas to calculate the capacity indicated in this plan, in the previous published plans and for all purpose above mentioned, comply with the standard defined by GTE (Gas Transmission Europe), european association of the natural gas transportation company, that presented in July 2004 to VIII Madrid Forum of the Regulator and European gas associations the document “Definition of available capacities at interconnection points in liberalized markets”. This document, published on GTE internet website in the page www.gte2.be/madridprocess, refers also to Guidelines for Good Practice adopted from VII Madrid Forum (GGP2), that establish that capacity calculation have to be based on a network model and flow simulations that take in account all the significant operational parameters needed for a safe and efficient use of the transportation system.

On the basis of conventions commonly used by European operators, transportation capacity is the highest quantity of gas that may be injected into the system during the Gas-day, at a specific point and transported from there to the consumption centres, in compliance with the technical and operational constraints defined in each section of the pipelines and of the highest performances of plants erected along the same pipelines. These capacities are estimated by means of hydraulic simulations of the network, performed in appropriate transportation scenarios and according to acknowledged technical standards. These simulations are carried out under steady state conditions and represent the average transportation day, with an established modelling of the network, of plants and of boundary conditions. The considered constraints take into account these approximations in the model used and constitute a security margin that guarantees actual availability of calculated transportation capacities, under real operating conditions.

Transportation capacity may be made available to users with transportation services of a firm or interruptible type. Estimation of firm transportation capacities, whose availability must be guaranteed in any situation and at any period of the thermal year, refers to cautious transportation scenarios and constraints. On the contrary, estimation of interruptible capacities uses existing transportation margins under special conditions or with less severe constraints.

The transportation of the firm capacity is guaranteed under every possible operational condition, since it is calculated taking into account the most severe market scenarios; it ensures that for any considered year, it is not possible to foresee a worse transportation situation other than unavailability or failures in the transportation structure, which cannot be foreseen in advance. The scenarios that have just been described may be considered as “special” operating conditions. Under “normal conditions”, which correspond to the usual operating conditions, the transportation capacities are prevalently subject to market fluctuations, in terms of entities and collocation, and to unavailability of plants, for example for ordinary or extraordinary maintenance. Under normal conditions it is possible to use transportation structures more, if less restrictive technical and operational constraints than those used for verifying special conditions, are assumed. With respect to inlet capacity values calculated under special conditions, additional capacity values, published as interruptible capacities, thus subject to reduction or interruption, depending on operating condition requirements, are obtained from the transport simulations of normal conditions.

Therefore, it is possible to summarise that performances of the transportation network may fluctuate between two conditions: a “normal” condition that may be encountered during every day operations, but that cannot be guaranteed during the whole year, to which “interruptible” capacity availability corresponds and a “special” condition that may be encountered and guaranteed every day of the year, to which the “firm” capacity corresponds.

In turn, interruptible capacity may be subdivided into two reference groups: annual and seasonal.

Some information on the entire transportation capacity calculation process on Snam Rete Gas network, including the technical characteristics of the simulation system, are indicated below, to be utilised by all users.

2.4 Operational constraints and boundary conditions used in simulations

2.4.1 Delivery pressures For the purpose of transportation verifications, reference is made to delivery pressures at the entry points, which have been defined, jointly with the foreign companies involved, on the basis of dimensioning calculations carried out in order to define in a complete way the reinforcement required for both systems, with respect to increases in volumes of transiting gas programmed on the basis of market requirements.

The assumed pressures constitute a fundamental reference for system dimensioning and operational service, and for this reason, in compliance with the Network Code they are notified to users by publication on the Transporter’s web site.

Currently valid delivery pressures are illustrated below: Entry Point Minimum contractual pressure (barg) Tarvisio 56.5 Gorizia 58 Passo Gries1 49 Mazara del Vallo 75 Gela 70

2.4.2 Maximum pressures of pipelines The maximum operating pressure of pipelines cannot exceed the maximum project pressure, a value that normally coincides with the pressure value from CPI, i.e. the pressure for which the authorisation is given by the competent authority (VVFF). In order to avoid exceeding the pressure by CPI along the pipelines, which could be caused by changes in elevation or by transitory transportation regimes, control and monitoring pressure systems are used, calibrated on “limit” pressure values of 1÷2 bar less than the allowed limit (the value is determined each time taking into account the system control tolerances). In some cases lower maximum operational values than those above are used on a temporary basis. These values are also taken into account when calculating capacity.

Some sections of pipelines relating to importation from Northern Europe and Russia, constructed in the Seventies and almost completely doubled or tripled with new pipelines, are operated at lower pressures down to 55 bar.

1 Pressure referred to the measurement plant of Masera

2.4.3 Minimum pressure along the pipelines In relation to the forecast configuration, in particular points of the transportation network, the minimum pressures required to guarantee system performances are identified. In particular, the minimum pressure at inlet of the compressor station normally assumes the value of 55 bar for importations from the South, and of 50 bar for those from the North. Similarly, minimum pressures are assumed at particular network points defined depending on the guarantee of minimum contractual pressures at Redelivery Points; the points concerned are the distribution nodes of Mortara and Sergnano, in which the lowest value is 50 bar.

It must be noted that modulation of loads withdrawn by the market during the day generate fluctuation of pressures on the network, reaching lower values than those shown by transportation simulations under steady state conditions. Pressure values assumed as permissible for any point on the network take into account both these daily fluctuations and those attributable to transients due to the most common operational conditions.

2.4.4 Design and operation of compressor stations As regards operating the compressor stations, the transportation conditions that require utilisation of turbo compressors limited to the maximum rated performances, to which an appropriate reduction factor is applied, are considered permissible. These coefficients allow for keeping adequate security margins in order to take into account, on one hand, approximations inherent in the modelling of unit operations and, on the other, adequate available performance margins, so as to be able to cope with operational conditions that may occur in reality (mainly daily and operational fluctuations of transportation) and that cannot be taken into consideration in simulations. Assumed coefficients of highest use of the turbo compressors are: - Power generated by the turbine equal to 95% of the maximum “on site” power; - Number of revolutions of compressor and turbine (RPM) equal to 100% of nominal revolutions (RPM)

For the purposes of security and reliability of the transportation system, at least one spare unit (or “emergency”) is installed in any plant, which, under normal operating conditions (including the most severe transportation scenarios), is able to replace each of the used units. This also allows for carrying out normal maintenance of the compressor units without interruption or transportation reduction. The number of spare units depends on the number and power of the compressors installed in the plant. For stations with up to three installed units, in general only one unit is kept for emergency (or two units of a lower capacity than those operating, provided that the sum of the respective powers is higher than or

equal to the power of each one of the functioning units). In the case of plants with four or more installed units, two units are also kept as spares with a unitary power that is at least equivalent to that of the functioning units.

A further constraint to be considered in plant operations is the range of head and permissible flow rates depending on the characteristics of the installed compressors, defined, in the design phase, in order to optimise the provided service operations. This may materialise in the limitation of the highest delivery pressures even in the presence of capacity available on turbine or, in other cases, in the need to use special couplings of installed units in some operating ranges.

Finally, it is clear that the delivery pressure cannot exceed the highest permissible pressure for the pipeline(s) downstream from compression, as previously explained.

2.4.5 Market scenarios They consist in all user off-takes from the Snam Rete Gas transportation system. For the purposes of defining network performances, these scenarios are defined from time to time so as to take into account the most severe transportation conditions. For the purposes of defining capacities at the Entry Points interconnected with the foreign pipelines, the most severe scenario for importation from Russia and Northern Africa is that of summer, in which as a result of reduced off-takes of the market along the line and of requirements for storage injection, the entry gas volumes must be transported for longer distances. In the case of the Point of Gries Pass, located in the vicinity of important consumption centres, seasonality is less emphasised; the most severe scenario may also be that of winter, as it has been shown by performed hydraulic simulations, since at some junction points of the network, levels of pressure that allow for suitable feeding of pipelines going out from here, must be guaranteed.

The choice of reasonably cautious conditions in which to carry out simulations constitutes a security factor. The choice of reference conditions considered to be the most severe guarantees the availability of capacity resulting under other reference conditions even in presence of deviations from these boundary conditions.

Verifications required for definition of the transportation capacities are carried out taking as reference scenarios of off-takes from the network based on the evolution of demand for gas in Italy during the next 10 years.

2.5 Interruptible capacities In the context of establishing firm transportation capacities, the quantity of annual interruptible transportation capacities and seasonal interruptible capacities are estimated for subsequent scenarios, the analyses of interruptible capacities are not very significant, since there is an increasing uncertainty concerning market off-takes and network structures, affected by maintenance operations to be planned, possible cases of unavailability of plants and time schedules for commissioning new reinforcement; therefore analyses are carried out each year only for the next year.

The characteristics of interruptible transportation capacities (annual or seasonal), in terms of the duration of interruptions and procedures for activating them, are published by the Transporter on his web site; a general description of them is given below.

2.5.1 Annual Interruptible Capacities Firm transportation capacities are those resulting from the most severe transportation scenarios that can be foreseen on the network. These quantities are transportable upon the request of the users for whom they are booked at any moment of the year, except in the periods when structural maintenance is carried out. Strictness with which these estimations are carried out, aligned with the standards of the European transportation companies, results from liabilities assumed by the Transporter towards users to guarantee, in some cases also for long period of time, reliable transportation of quantities, object of the contract. In many cases however, effective operation of the network is carried out also with lower pressure values, which are acceptable at the operational level but that cannot be considered as “usual” for “ex ante” determination of capacities that will be booked. Other scenario values, such as for example, disposal on the network, of withdrawals for storage, may also affect estimation.

In these cases, which are, however, situations compatible with normal operations, further transportation capacities, with respect to the firm ones, may appear. In order to estimate these capacities, reference parameters in the hydraulic calculation (typically lowest pressures along the network), which are less restrictive than those used for calculating firm capacities, but that guarantee however suitable security margins, may be used. These capacities may be defined as annual interruptible capacities and have the following characteristics: • Availability is secured unless there are particular events of the network (configuration of off-takes reduced on the whole network or on part of it that affects capacity of transportation for importation; high requests of pressure at some points along the importation line in order to meet higher than expected local market requests or special network configurations).

• For given types of possible interruptions that will more likely occur during weekends and holiday periods, or however of lower market off- take (which is usually planned slightly in advance), a few days’ notice can usually be given for interruptions or reductions in the annual interruptible capacity (at weekly planning level).

In some cases (such as importation from North Europe) in which seasonal effects of off-takes on transportation capacities are small, interruptible transportation capacities may be calculated on the basis of an average value of interruptible capacities available during the various periods of the year.

2.5.2 Seasonal Interruptible Capacities There is a second group of interruptible capacities, to be considered as the capacity that could be transported in addition to the annual one, affected by external factors such as variability of off-takes due to climatic conditions, which is why the term “seasonal” is used. During the winter, as a result of a drop in temperature that implies an increase in off-takes, it is indeed possible to inject a higher quantity of gas from the Points of importation without overloading the importation lines themselves to the same extent. As the term used to describe them implies, with interruptible capacities the Transporter reserves the right to reduce the quantity of imported gas, either totally or partially, any time conditions require it, to safeguard the status of the network and operational security, maximising coverage of market demand. To determine these capacities, average capacities of those relating to verifications with standard constraints of the network, similar to those used for calculating firm capacities, and those with constraints similar to those used for calculating annual interruptible capacities are considered. Analyses are carried out with a winter holiday scenario (January). This category of capacities has the following characteristics: • period of availability of this capacity is normally from October to March; • given the type of possible interruptions that are more likely to happen during weekends and winter holiday periods, coinciding with particularly mild weather, normally foreseeable 2/3 days in advance, a few days’ notice can be foreseen for interruptions or reductions in seasonal interruptible capacity

2.6 Simulation programs Transportation of gas on the Transporter’s network is checked by hydraulic simulations carried out using special “ad hoc” simulation systems, developed for simulating a meshed network such as the one operated by Snam Rete Gas. For calculating capacities at Entry Points on the National Network interconnected with foreign pipelines, the simulation system called SIRE produced, according to the Transporter’s specification, by the company TEMARS (currently called EniData) of Bologna, which is also responsible for its maintenance and updating, has been used.

2.6.1 The SIRE system The SIRE system is represented by a set of programs aimed at simulating meshed networks and compressor stations (the latter also one at a time and “disconnected” from the network) either under steady or dynamic conditions. Interaction with the system occurs by means of graphical interface that enables both the introduction of data required for the “topological” description of the network and the transportation scenarios to be checked and analysis of simulation results. Main characteristics of system allow for : • “modelling” of the network representing it by sections of network, of length not higher than 50 km, that connect significant points, called “calculation points”; these points correspond, in the model, to physical elements such as main connection points between pipelines, detachment points of shunts or of distribution networks, changes of diameter, important changes of depth profile of pipelines. The “calculation points” are also located at the level of the compressor stations and of injection points in the network from importations or from more important national productions; • simulation of a network for calculation of the following sizes: o pressure, temperature and composition of gas at all the represented points of the network ; o flow rate and composition of gas in any section; o working points of turbines and active compressors and calculation of the main related sizes; o determination of operational parameters in the special components (plants, valves, importations, wells, storage facilities, off-takes); • concentration of off-takes of gas in the “calculation points”, as well as quantities of gas injected in the network from the inlet points; • resolution of a system of equations related to balances of energy, flow rate, composition and transportation equations according to formulas and models acknowledged by scientific literature and by technical associations for gas; • utilisation of a model related to compressor stations, based on: o application of the criterion for characteristic control of plant for distribution of flow rate between the units;

o realistic simulation of the working point of compressors and turbines, thanks to the use of a mathematical model that describes effective characteristic curves of the single machines, resulting from field data (where available) or from expected curves (“expected”) provided with by the manufacturers; this simulation allows for determination, with a good approximation, of the working perimeter of stations based on the effective limit curves (antisurge, minimum and maximum number of revolutions, maximum power); o calculation of sizes of units and plant based the model of units (for example: consumption of gas, power required by the compressor and power supplied by the turbine).

Adopted calculation models use the following base main equations:

Calculation of pressure drop Equation of Fergusson Equation of status for calculation of Z and deduced factors Equation BWR Calculation of friction factor Equation of Colebrook

Calculation of viscosity Method of Dean-Stiel

2.6.2 Model of network and simulated scenarios For the purposes of transportation verification of the importation capacities, transportation is simulated, under the steady state conditions, on a network substantially coinciding with the National Gas Pipeline Network. In the simulated network some significant sections of the transportation network that are not part of the National Network, whose structures are especially affected by the upstream network structure, are represented. On the contrary, current off-takes and injections of gas, on networks diverted from the simulated network, but not represented here, are taken into account by means of appropriate criteria for “aggregation” that consider structures of the same networks.

2.6.3 Reports The system makes it possible to print the main results in both graphical and alphanumerical form, with respect to flow rates of gas and to performances of the compressor stations. The graphical representation of the network of the natural gas pipelines is schematic but sufficiently correlated to the real geographical layout.

3 ATTACHMENTS

List of Development Projects NATIONAL NETWORK

Diameter Length Number Power Diameter Length Number Power (mm) (km) of units (MW) (mm) (km) of units (MW)

Add. Import. Russia: sect. Tarvisio - Malborghetto 1200 24 Nat. gas pipel. Gela - Enna 900 67 Add. Import. Russia: sect. Malborghetto - Bordano 1200 45 Dorsale Adriatica: sect. Massafra - Biccari 1200 193 Add. Import. Russia: sect. Bordano - Flaibano 1200 32 Dorsale Adriatica: sect. Biccari - Campochiaro 1200 69 Add. Import. Russia: sect. Flaibano - Oderzo 1200 52 Dorsale Adriatica: sect. Sulmona - Foligno 1200 165 Add. Import. Russia: sect. Istrana - Camisano 1200 37 Dorsale Adriatica: sect. Foligno - Sestino 1200 113 Add. Import. Russia: sect. Camisano - Zimella 1400 43 Dorsale Adriatica: sect. Sestino - Minerbio 1200 143 Add. Import. Russia: upgr. Malborghetto compr. station - - Compr. station of Sulmona 3 33 Reinf. Transmed: pipel. Enna - Montalbano 1200 86 Compr. station of Poggio Renatico (Fe) 3 50 Reinf. Transmed: pipel. Palmi - Martirano 1200 112 Compr. station of Minerbio 2 20 Reinf. Transmed: pipel. Campochiaro - Sulmona 1200 94 Nat. Gas pipel. Pontremoli - Parma 900 70 Reinf. Transmed: Enna compr. station (piping) - - Reinf. nat. gas pipel. Mortara - Alessandria 750 45 Reinf. Transmed: Gallese compr. station (reinf.) 1 25 Reinf. nat. gas pipel. Alessandria - Oviglio 750 12 Reinf. Transmed: Melizzano compr. station (piping) - - Connect. storage of Collalto 600 15 Reinf. Transmed: Melizzano compr. station (reinf.) 1 25 Nat. gas pipel. Gagliano - Sparacollo 400 16 Reinf. Transmed: Messina compr. station (reinf.) 2 60 Doub. pipel. VE-TN: sect. Vigasio - Bussolengo 500 15 Reinf. Transmed: Montesano compr. station (piping) - - Doub. pipel. VE-TN: sect. Bosentino - Trento 400 9 Reinf. Transmed: Montesano compr. station (reinf.) 1 25 New connect. internconnect. San Marco 300 1.5 Reinf. Transmed: Tarsia compr. station (piping) - - Reinf. Transmed: Tarsia compr. station (reinf.) 1 25 Reinf. Transmed: Terranuova compr. station (reinf.) 1 12

REGIONAL NETWORK Diameter Length Diameter Length (mm) (km) (mm) (km) Coll. Bergantino - S. Giorgio Di Mantova 750 36,4 BA 11: All. Di Castelmezzano (PZ) 100 6,2 Met. Oviglio-Ponti 750 37,5 Pot. Derivazione Per Lucera (FG) 300 6,2 Pot. Met. Iiª Alimentazione Di Napoli 750 20,7 CL 8: Dir. Per Carpanzano (CS) 150 5,8 Pot. Met. Benevento-Cisterna Tr. Melizzano-Piana Di M.te Verna 750 20,0 Pot. All. Com. Cassolnovo 200 5,7 Pot. Sergnano - Casirate 750 13,0 CL 2: Der. Per Mottafollone (CS) 200 5,6 Pot. Der. per Bagnoli 750 16,4 All. Comune Di Alia (Pa) 100 5,6 Pot. Deriv. per Sermide: Met. Castagnaro-Bergantino 750 11,7 Pot Spina Di Casei Gerola 250 5,5 Met. Bondeno - Ferrara 600 11,6 Pot. Der.Ne Per Adria (RO) 200 5,5 Pot. Alessandria - Tortona 600 17,0 CL 24: All. Di Casabona (KR) 100 5,5 Pot Spina Di Genova 1°Tratto 600 3,0 Pot. Met. Lurago - Ponte Lambro 300 5,0 Met. Giarratana-Solarino 600 37,5 Pot. Der. Sud Cantu' (Co) 250 4,7 Coll. Der. per Lecco al Metanodotto per la Valtellina 600 1,7 Pot.(Parziale)Spina A/I Foggia Incoronata 250 4,5 Met. Capizzi - Mistretta 500 16,5 Radd. Derivazione Per Suzzara 2° Tratto 300 4,3 Met. Mornico Al Serio - Zanica 500 13,5 Pot. Spina Cava Dei Tirreni 250 4,3 Pot. Cosseria - Mallare 500 0,0 Potenz. All.To Comune Di S.Pietro Di Morubio 250 4,2 Met. Mornico Al Serio-Travagliato 500 24,0 BA 1: All. Di S. Martino d'Agri 100 4,1 Met. Azzano Mella - Travagliato 500 8,2 BA 8: All. Di Accettura (MT) 100 4,0 Met. Cherasco - Cuneo 500 37,0 Pot. Der. Manzano-Buttrio (UD) 250 4,0 Met. Lainate - Castellanza 500 20,5 Pot. Deriv. Per Gottolengo (Bs) 250 4,0 Pot. Bindisi-Arnesano: 1°/ 2° Tratto 500 26,2 Pot. Der. Per Garbagnate 250 4,0 Pot. Brindisi - Arnesano - 2° Tratto 500 7,6 Pot. Deriv. Per Pandino E Spino D'adda 200 3,8 Coll. S.P. Clarenza - S. Gregorio 400 9,5 Pot. Der. Per Fabriano E Sassoferrato 150 3,6 Metanodotto Meleti - Maccastorna 400 2,9 Pot. Der. Per Varese 300 3,5 2° Pot. Met. Santerno - Imola 400 6,3 Potenz.Deriva. Per Casale Sul Sile (TV) 150 3,5 Pot. Deriv. Per Sestri Levante 1° Tratto 400 1,0 Pot. Reti Fiorenzuola E Castell'arquato 150 3,3 Pot. Coll. Met. Boltiere-Seriate Con Cabina di Osio 400 2,0 Pot.Spi.Terni 1°Tratto (Tr) 300 3,2 Collegamento Pietrafitta - Perugia 400 25,4 Pot. Spina Di Enna 2° tratto 150 3,2 Met. Cazzago Brabbia-Besozzo 400 13,3 Pot. Der.Ne Per Suzzara (MN) 300 3,0 Pot. Spina Sud Di Mantova 400 1,3 Coll. Deriv. Per Verzuolo - All. Burgo 300 3,0 Met. Borgotaro - Sestri Levante 400 8,5 Pot. Deriv. Per Salo' (Bs) 300 3,0 Potenziamento Forli'-Faenza 400 21,7 Pot. Z.I. Di Vicenza 250 3,0 Metanodotto Mira-Mestre 400 7,1 Coll. Nuova C.R. Teverola Con Spina Di M 250 3,0 Met. Mondovi'-Cuneo 400 16,2 Radd. All.Comune Di Meldola (Fo) 200 3,0 Pot. Pinerolo-Perosa 400 5,6 Pot. Spina Per Cornate D'adda (Mi) 200 3,0 Met. Contursi-Battipaglia 400 21,6 Pot. All.To C.Ne Di Giovinazzo 150 3,0 Met. Gattinara-Prato Sesia E Opere C.Sse 400 17,8 Radd. Derivazione Per Castelfidardo 2° Tratto 150 3,0 Met. Triggiano-Monopoli 300 30,8 Pot. All. 3ª Pr. Com. S.Colombano Al Lambro 150 2,8 Met. Coll. Grottole-Albano Di Lucania 300 26,0 Pot. Deriv. Per Paderno D'adda (Lc) 250 2,7 Der. Cagnano V.-Carpino: 2° Tratto 250 22,1 Pot. Der. Per Trezzano Rosa 250 2,5 Der.Sannicola-Ugento-Tricase: 3° Tratto 300 15,1 Pot. All. 2ª Pr. Com. Di Missaglia (Lc) 250 2,5 Pot. Met. Gozzano-Domodossola 200 13,1 Pot. All. 1ª Pr. Com. Di Missaglia (Lc) 250 2,5 Colleg. Carpi-Reggiolo 300 11,6 Pot.Spina Di Enna 1° tratto 200 2,5 Pot.Der.Per Riva Del Garda 300 11,0 Pot. Deriv. Per Brenta (Va) 200 2,5 Metanodotto Venzone-Tolmezzo 250 10,7 Pot. All. Comune Di Alfonsine 1° Parte 150 2,5 Pot. Der. Per Abbadia Lariana 250 9,9 All. Comune Di Scampitella (Av) 100 2,5 Pot.Spi.Piombino Dn 300 300 7,6 Pot. Deriv. Per Besnate (Va) 250 2,3 Met. Settala - Rodano 300 7,4 Radd. All. Buton Ozzano Emilia (Bo) 200 2,3 Radd.Der.Pontelongo 200 7,1 Pot. Spina di Corchiano 1° tronco 150 2,2 Rif.Der.Vittorio Veneto (TV) 250 6,9 Potenziamento Della Derivazione Per Copp 250 2,2 Pot.Der.X Arzignano 300 6,7 CA 13: All. Di Apollosa (BN) 100 2,2 Pot. Spina Nord Di Casalpusterlengo 200 6,7 Pot. Spina Per Dresano 200 2,2 Pot.Raldon-Legnago (Vr) 250 6,5 Pot. Der. Per Mozzate 250 2,2 Potenz. All. Com. Di Prato 4a Presa 200 2,2 Pot. All. Comune Di Pomigliano D'arco 200 0,6 Pot.All.Com.Trani 200 2,1 Pot. Spina Per Osnago (Lc) 300 0,5 Pot.Spina A.S.I. San Nicola Di 200 2,1 Pot. Der. Per Castiglione Delle Stiviere 250 0,5 Pot. All. Com. Torrevecchia Pia (Pv) 150 2,1 Pot. All.To C.Ne Di Marano Di Napoli 150 0,5 Pot. Derivaz. Sebring Fontebasso 150 2,1 Pot.Spi.Nord Civitacastellana Trat 100 0,4 Coll. Alim. Nord Mi - Lentate S.S. E Imp 300 2,0 Pot. All. 1ª Pr. Com. Di Gavirate (Va) 200 0,3 Pot. Der. Per Mariano Comense 300 2,0 Pot. Der. Per Albiolo 250 0,3 Pot. Der. Per Lozzolo 200 2,0 Ricl.Der.per Nogarole Rocca (VR) 200 0,2 Pot. Deriv. Per Novate Milanese (Mi) 200 2,0 Pot. Allacc. 2ª Pr. Com. Di Lissone (Mi) 200 0,2 32 Radd. Diramazione Per Spezzano 200 2,0 Pot. All.Com. Di Nocera Inferiore 250 0,2

Diameter Length Diameter Length (mm) (km) (mm) (km) Radd. Diramazione Per Spezzano 200 2,0 Pot. All.Com. Di Nocera Inferiore 250 0,2 Pot. Der. Concorezzo Nord 200 1,8 Pot. Allacc. Com. Bussero/Pessano/Capona 200 0,1 Pot. All. Com. Palo Del Colle 150 1,8 Pot.All.Com.Mirano 2a Presa 150 0,1 Pot. Spina Z.I. Rovigo 250 1,8 All. Comune Di Rocca Di Neto (Kr) 100 0,1 Pot. Spina Per Torre De' Roveri (Bg) 200 1,7 All. Comune Di Ciro' 100 0,1 Pot. Spina Per Cart. Fornaci Di Fagnano 200 1,7 All. Belsito (CS) 100 0,1 Potenziamento Derivazione Per Bellusco 200 1,7 Pot. All. 3ª Pr. Com. Di Saronno (Va) 200 0,1 Pot. Deriv. Per Piubega (Mn) 200 1,7 Pot. All. Com. di Lamezia (Presa Sambiase) 150 0,1 Pot.Spina Nord Treviso 200 1,6 All. Settingiano (CZ) 150 0,1 Pot. All. Com. Borghetto Lodigiano (Lo) 150 1,6 Coll.All.Edison Gas Jesi Con Deriv. per Jesi 250 0,1 Pot. All. 1ª Pr. Com. Flero (Bs) 150 1,6 Pot. All. Comune Di Mozzo (Bg) 150 0,1 Pot. Deriv. Per Turate/Cislago (Co) 150 1,6 Pot. All.To C.Ne Di Casandrino 150 < 0,1 Pot. Met. Ceriano Laghetto - Saronno 300 1,5 Pot. All.To C.Ne Di Qualiano E Villaricca 150 < 0,1 Pot. Rete Di Montecchio Emilia 200 1,4 Pot. All. 3ª Pr. Com. Di Brescia "Bedizzole" 250 < 0,1 Pot. Der. Per Vanzago 250 1,4 Pot.All.Com. Bitonto 150 < 0,1 Pot. All. 1ª Pr. Com. Cesate (Mi) 200 1,3 Pot. All.To C.Ne Di Salerno 1a Presa 150 < 0,1 Pot. Spina Sud Di Crema 200 1,3 Pot. All.To A.R. Di Scafati (4216 01) 150 < 0,1 Pot. Derivazione Per Ponzano Magra 100 1,3 Pot. All.To C.Ne Di Lanciano 150 < 0,1 Pot. Spina Di Marcon (Ve) 200 1,3 Presa Com.Garbagna Novarese-Nibbiola(No) 100 < 0,1 All. Sellia (CZ) 150 1,3 Presa Com. Cittiglio (Va) 100 < 0,1 Pot. Der. Per Schio - Piovene Rocchette 250 1,2 Presa Com. Di Ronco Briantino (Mi) 150 < 0,1 All. Buonabitacolo (SA) 100 1,1 Presa Com. Di Mezzago (Mi) 150 < 0,1 Pot.Der.Rossano V.To 200 1,1 Pot.Imp.Rid.789 Scandicci Sud Q=300.000 Sm3/h 0 0,0 Pot. Allacciamento Bemberg - Gozzano (VB 200 1,1 Pot.Imp.Rid.N°737 Di Cisterna Sud -- -- Pot. Deriv. Per Assago (Mi) 200 1,0 Pot.Imp.Reg.N.562 "La Stanga" -- -- Pot. Deriv. Per Vittuone/Sedriano (Mi) 200 1,0 Pot. Impianto Riduzione Ferrara N°558 -- -- Pot. Allacc. Europizzi Di Urgnano (Bg) 200 1,0 Potenziamento Teleregolazione Rete Basso Piemonte -- -- Pot. Diramazione Viale Rimembranze Brà 2a presa 150 1,0 Potenziamento Impianti Di Riduzione / Regolazione minori N° 29 Radd. All.Gessi Emiliani 150 1,0 Allacciamenti utenze industriali, civili e termoelettriche N° 150 Pot. Derivazione Per Curno (Bg) 250 0,9 Pot. Deriv. Per Monza/V.Le Sicilia 250 0,9 Pot. Deriv. Per Arzano-Casavatore 200 0,9 Potenziamento All.To Comune Di Calci 150 0,9 Radd. All.Com.Portomaggiore 150 0,9 Pot.Allac.Per Bernareggio 150 0,8 Pot. All. Pontenossa Spa 200 0,8 Spi.Migliarino Pis.Z.I. 100 0,8 Pot. Deriv. Per Casalbuttano (Cr) 150 0,8 Pot. All.To C.Ne Di S. Nicola La Strada 200 0,7 Pot. Spina Per Cassina De' Pecchi (Mi) 200 0,7 Pot. Spina Per S. Giorgio Su Legnano 150 0,7 Pot. Allacciamento Borgomanero 2° Presa 150 0,7 All. Comune Di Santa Severina (Kr) 100 0,7