2014 Reliability Report. (Summary)

Transcription

1 Anne-Marie DENIS 26 June 2015 (Summary) Every year, RTE publishes a reliability report for the past year. This report includes a number of results from previous years so that year-to-year comparisons can be drawn and long-term trends analysed. The 2014 report underlines the major factors that have impacted on the reliability of the electrical power system, without focusing exclusively on Significant System Events (ESS). It describes various factors which contribute to present and future reliability of the power system, as well as the ways in which the various parties involved in the electrical power system interact across the whole European interconnected network. To make this document easier to read, its structure has been overhauled this year. (The complete document in French is available on Risk audit department Reliability Audit Task Force Tour Initiale 1 terrasse Bellini-TSA La défense CEDEX TEL: +33 (0) FAX: +33 (0)

2 Page: 2/11 Summary of the 2014 reliability report Every year, RTE publishes a reliability report for the past year. This year s document lays out the main factors that affected the electrical power system's operational reliability in 2014 and the initiatives currently under way to ensure its reliability in the future, within the framework of the European interconnected network. It also serves as a means of drawing comparisons with previous years and highlighting long-term trends in different areas. 1- Significant system events better results than in 2012 and 2013 Every year, RTE measures the reliability of the electrical power system by adding up the number of Significant System Events (ESS). These are classified according to a scale of severity that ranges from 0 to F. These events correspond to incidents that can result from a broad range of factors. RTE s scale is compatible with the ICS (Incident Classification Scale) scale which comprises four levels defined by ENTSO-E. With 30 "A" level ESSs and 1 "B" level ESS, 2014 was a better year than 2012 and The most severe event of 2014 was the loss of the Regional Control System (SRC) for more than two hours. The consequence of this was a loss of observability in the south-east region, which in turn activated the switch to control centre assistance provided by monitoring tools located in substations of this area. Regarding the "A" level ESSs, falls were recorded in all areas (grid, operation, generation, distribution), except operation means. Changes made to the ESS grid which have been applicable since 1 January 2014 have actually broadened the scope of this specific area in order to tighten requirements. Among the "A" level ESSs, 4 were the result of study tools for power system control being unavailable for several hours, 3 were for the definitive tripping of several outgoing feeders from 400 kv and 225 kv substations, 2 involved the loss of servers in different regions, 2 involved a significant decrease in generation and the reduction of operational margins and 2 involved periodic test failures for reenergising files to nuclear power plants. As far as losses of primary and secondary frequency and voltage control of generating units lasting more than two hours are concerned, ("0" level ESSs), 2014 was very similar to 2013: satisfactory overall. 2- Operational conditions encountered good weather fall in gross consumption highest exports since 2002 higher infra-daily exchanges As far as weather in 2014 was concerned, the year was unusually hot in France and Europe, while the summer was particularly cool. Across the year as a whole, average temperatures were 1.2 C higher than normal. Electricity demand peaked at 82,500 MW its lowest since 2004 and 19,600 MW below the February 2012 peak. The temperature gradient during the winter months remained stable at 2400 MW/ C. Gross consumption was 6% lower than in 2013: TWh its lowest since There is significant variation in consumption levels from one year to the next, both in terms of annual energy consumption and peaks in demand. This means that the electrical power system must be able to adapt to highly uncertain and extreme weather conditions particularly cold spells. France's annual export balance stood at 65.1 TWh its highest since It exported to all of its bordering countries, except Germany TWh of electricity was exported to Belgium over the winter in order to help balance supply and demand, despite the unavailability in the country's generation mix. The variability of import and export situations at any period of the year (and therefore the variability of the physical flows across the grid) continues to grow from year to year with increased use of renewable energies and the possibilities for short term market optimisation. The infra-daily share of cross-border exchanges reached 15% of contractual cross-border exchanges. 2-1 Short-term supply / demand balance and frequency

3 Page: 3/11 some lack of flexibility in the means used to manage supply-demand balance some complex changes in cross-border power exchange programmes frequency stability better than in 2013 With 11 rising and decreasing margin deficits, 2014 proved less constrained than 2013 in terms of managing supply-demand balance. Over a year which saw relatively good weather and during which French electricity generation plants demonstrated high levels of availability, these shortfalls in margins may, however, show an increased need for flexibility in the way in which supply-demand balance is managed against a background which is seeing rapid changes in energy mix. This situation emphasises the need for RTE to strengthen its contractual requirements and to continue to monitor the parties involved in order to make sure that they are aware of the requirement to declare both technical limitations affecting generation and actual production via the Balancing Mechanism. The trend which got under way in 2013 for the frequency stability of the Interconnected European power system continued, with a significant fall in the number of both upwards and downwards biases. The annual cumulative duration of the most risky circumstances during which the European grid consumed a significant proportion of its primary reserves (exposing it to further risk in the event of a new event) totaled 59 minutes (as opposed to 1 hour and 34 minutes in 2013). With a minimum of Hz, 2014 did not see any bias over 150 mhz. As far as high-level frequencies are concerned, one increase up to Hz ( Hz in 2013) was logged. This was a little lower than the 50.2 Hz threshold above which photovoltaic production is triggered. One A level ESS (three in 2013) was logged for a frequency deviation of more than 100 mhz. This was observed for 1 minute and 30 seconds during the 1 AM change in cross border programme on 18 December. The quality of frequency control in the French zone and its contribution to controlling European frequency deviations can be evaluated by an indicator which measures the number of times that the power-frequency control deviation in the French zone is not corrected within 15 minutes. This indicator s trend reflects an increase in the number of situations where adjustments and the resources available were not flexible enough to provide operators with the flexibility they needed to rapidly correct major power fluctuations (during hourly changes in the cross border programmes up to several GW). To more effectively predict situations where French regulation could have a damaging impact on the European frequency and prepare for the necessary actions to be taken, RTE has developed a forecasting tool: MARTI (intra-day real-time forecast model for frequency control). Operators can use it to devise adjustment strategies to control frequency based on the resources they have available and how long it takes to implement them. In October 2014, the short-term supply-demand balance management tools used at the National System Operating Centre were presented to ENTSO-E, the aim being to more effectively standardise and coordinate methods and tools. At the same time, in 2014, ENTSO-E conducted research in order to find out just how capable the interconnected system was of withstanding events that generated unbalances of 1000 MW and above, correlating the frequency deviation with the amplitude of the event. This type of monitoring over several years is needed in order to characterise high-risk frequency situations, particularly since the overall inertia of facilities in Europe is tending to decrease as a result of the incorporation of renewable energies into energy mixes and the increasing number of converting stations being installed. In mid-2014, RTE and European TSOs began preparatory risk analysis and coordination work in order to manage supply-demand balance and European frequency for the eclipse of 20 March Voltage management a successful methodology for studying high voltages installation of new compensation means (Nanterre Reactive Power Static Var Compensator) The year was not a particularly cold one and there were no particularly constraining border transits. The risk of a voltage collapse was therefore low and no significant damage to the voltage profile was logged. The particularly mild winter meant that unscheduled outages of the 400 kv capacitor banks could be managed. However, in anticipation of harsher winters and more difficult conditions, RTE continued with its drive to commission new compensators, optimising the command & control algorithms of this type of device, using sophisticated analysis tools and continuing work with producers on optimising the capacities of generators to supply or absorb reactive power.

4 Page: 4/ therefore saw the installation of capacitor banks in the south-west and in Normandy, together with a Reactive Power Static Var Compensator at the 225 kv substation in Nanterre, designed to improve voltage stability in the West Paris region. Work continued on bolstering the Voltage Defence Plan. Managing the occurrence of excessively high voltages which are less directly critical for reliability purposes requires the activation of inductive reactors, the disconnection of overhead lines or cables and the absorption of reactive power by generating units. This can potentially weaken the electrical power system. These situations occur more frequently as a result of the development of underground networks and the increase of distributed renewable sources. Work carried out with producers and distribution system operators is under way within the framework of the drive to develop new voltage ancillary services rules. These will be used to respond effectively to the need to manage both low and high voltages. A method for studying high voltages in order to inform investment decisions was trialed in 2013 and has now been approved; it is now being applied in several studies across all of France. In the south-east, studies have been launched with TERNA for the coordinated management of the voltage profile across the cross-border region. These joint initiatives with other TSOs focused on managing high voltages are likely to be bolstered in the future. 2-3 Cross-border exchange management, congestion management preparing for the future commissioning of the France-Spain HVDC interconnection postponement of the market coupling by the Flow-Based method testing of the "safety net" across south-east France Flows through the French grid were well managed in This can be attributed to a number of economic factors, as well as structural and organisational factors, including improvements in the efficiency with which the regional grids are managed through CORESO, which has enabled coordinated initiatives to be implemented among TSOs. As was the case in 2013, the limitations in the capacity for exchanges between France and Germany were reached nearly half of the time. This was due to congestion on the grids resulting from wind power generation in northern Germany. As far as Spain is concerned, the interconnection was saturated 67% of the time, 45% of the time in the France-to-Spain direction. The capacity for exchanges between the two countries will be doubled in 2015 when the HVDC Baixas-Santa Llogaia link comes online. Significant joint common work with REE on preparing for the commissioning of the infrastructure was carried out in 2014, including the definition of the hybrid operating mode combining the "fixed point setting" and alternative signal emulation" modes. The link between France and UK enjoyed a high level of availability in 2014, meaning increase exchanges with the UK. Together with ELIA and TENNET-NL, RTE implemented an operational process managed by CORESO and approved by all regulators across the Central Western European zone. This process offers the option in emergency situations to modify the net transfer capacities across the region so as to increase import capacities in Belgium. This way, the country is better able to handle several nuclear power plants being unavailable during the winter. At ELIA s request, the operational implementation of the "flow-based" market coupling method (which models the link between commercial exchanges and physical flows and which was initially scheduled to come into service at the end of 2014) was postponed until May 2015 following a fruitful "parallel run" which bolstered operational coordination within the Central Western European zone and further harmonised safety rules over this zone. And in autumn 2014, the south-eastern French safety net came into service for testing. With three new 225 kv underground links and suitable inductance coils, it will strengthen the electricity supply structure for the region. 2-4 Short-circuits high number of lightning strikes on structures, start of the Automatic Fault Location project The high number of lightning strikes in 2014 resulted in an increase in the number of short-circuits affecting transport structures. However, this increase did not have any impact on the frequency of power supply outages which actually fell compared with Across France as a whole, the main

5 Page: 5/11 causes of short-circuits were atmospheric in nature: 50% were due to storms (84% in the southeast), 5.3% were due to wind and flooding. Equipment damage was the reason for 2.9% of shortcircuits saw a proven cause rate of 62%, lower than in Among the "presumed" causes, a significant share can be attributed to bird activity. The share of permanent faults accounted for 2.8% of the total lower than last year. These permanent faults lead to the loss of the facility, whereas transient short-circuits do not affect the availability of the facilities when the protecting relays are working correctly. Only 5% of faults affecting the 400 kv network were multi-phase faults. In particular operating conditions, an incorrectly eliminated multi-phase fault can compromise the transient stability of the generating units. And in relation to this, fault elimination times logged for the 400kV system show that the vast majority of faults were dealt with within their critical clearing time. The risk of a loss of stability was therefore very low. Given the significant number of faults every year that impact the network, particularly during the thunderstorm season, and the consequences they can have (power supply outages for subscribers), in 2014, RTE initiated the Automatic Fault Location project. This way, a fault on a given structure can be found more quickly, thus reducing the period of time during which the faulty line is unavailable. 3-Hardware reliability components 3-1 Generating units Reduction in reactive capacity limitations for generating units 85% success rate in islanding NPPs 90% success rate in re-energizing voltage routes to NPPs The role that generating units play in voltage control means that they also play an important role in reliability management. Limitations in reactive power supply can penalise the management of low voltages (risk of voltage collapse); limitations in reactive power absorption can result in high voltages (which presents a risk for equipment). EDF and RTE hold discussions on a twice-yearly basis about the reactive capacities of generating units and their limitations. This enables RTE to conduct precise dynamic voltage studies, using realistic Q/U diagrams. The trend that got under way a few years to reduce reactive capacity variations of generating units continued into 2014: total absorption biases are below the industrial event that is considered "normal"; total biases in terms of supply are also considerably lower than previously and should be brought to the "normal" level in year Every year, in anticipation of a significant part of the country being possibly disconnected from the electricity grid as a result of a large-scale incident and of the need to resume service, RTE and EDF carry out islanding tests on nuclear power plants and voltage recovery tests. These ring tests are conducted every four years and serve as a means of verifying the islanding capacities of power units and of checking the physical behaviour of the voltage recovery route equipment. They are also an opportunity to train EDF s and RTE s operators to take effective actions together in such rare and stressful situations. 3-2 Network equipment 83% of faults on the 400 kv network eliminated in less than 80 ms 95.4% availability of protection system and automatic relays triggered on a fault all lines monitored to withstand transitory overloads as of 1 January 2015 Analysing the faults clearing process by the protection systems and circuit breakers provides information about the suitability and the efficiency of maintenance plans for the equipment. In 2014, 83% of faults on the 400 kv network were eliminated in less than 80 ms and 94% in less than 100 ms. These measurements are in accordance with the 80 ms reference value specified in RTE s operating rules in order to maintain stability. The availability rate of protection systems and automatic systems triggered on faults was 95.4%. 8 level 0 ESSs can be attributed to malfunctioning of the 400 kv and 225 kv busbar differential protection devices. A renewal policy is being implemented for these protective devices, which play a major role in the fast and selective elimination of faults. This policy is in keeping with the anomaly rates recorded for the various technical categories of these protection devices. Regarding digital protections against loss of synchronism, 2014 saw a fault on a 225 kv cross-border line with Belgium.

6 Page: 6/11 The unavailability of transmission structures was higher than in 2013 (all causes taken together), with figures that were similar to those for However, the availability of the 2 GW link between France and the UK was high: thanks to work carried out, it was used for export purposes 99% of the time. As far as switch gears at substations are concerned (essential components for operational reliability), the year saw 105 level 0 ESSs across the whole country associated with busbar disconnectors malfunctioning. These figures were lower than in previous years, demonstrating that the measures implemented have been effective, while at the same time underlining the need to continue with them. In order to operate the network at levels that are close to its limitations, all links switched from IMAP monitoring (Maximum Permissible Permanent Current) to IST monitoring (Transient Overload Intensity) on 1 January This system takes the specific operational conditions of each piece of equipment into account. And within the framework of the Ampacité project, dynamic tests to monitor the transmission capacities of equipment were extended. A study was carried out with ELIA in the second half of 2014 in order to analyse the opportunity for deploying monitoring systems on the links between France and Belgium against a weakened supply-demand balance in Belgium during the winter Tools, projects and expanded opportunities increase in total periods of loss of observability and operability the SIDRE (Inter regional control centre Support) system will soon be operational the EAS (ENTSO-E Awareness System) monitoring system deployed over the CNES (National System Operating Centre) commissioning of the COMPARE operator warning module as part of the ECCT (Coordinated Short-Term Studies) process deployment of the Safety Telephone System (STS)-V2 increased security of the IS system fruitful tests at the interface between the Public Transmission system & Distribution Grid (reactive power management) The National Control System (SNC) was not affected by any accidental unavailability in As far as the Regional Control Systems (SRC) are concerned, the year saw 4 level A ESSs and 1 level B ESS (the most serious incident in 2014). All the accidental events taken together resulted in a total loss of observability that was 2.4 times higher than in The total loss of operability was 1.3 times higher than in In order to deal with the ageing of the control systems currently in use and to provide operators with a unique control system, RTE launched the STANWAY project. The SIDRE (Inter regional control centre Support) project which guarantees the continuity of control following an incident by permitting one control centre to be replaced by the control centre of another region is a major improvement in terms of ensuring the reliability during disturbed conditions. Work progressed well in 2014 and the three recovery zones of Nantes/Saint-Quentin, Lille/Nancy and Lyon/Marseille/Toulouse will be operational in The Safeguard Alarm System (SAS), which is essential for controlling high-risk or downgraded situations, returned a global downtime rate of 0.36% (0.25% in 2013). Its replacement the Security Data Control & Warning Safeguard System (SACIS) was accepted by RTE on a test platform and the equipment that makes it up was installed at central sites. The ENTSO-E Awareness monitoring System (EAS) is now operational in all European TSO control rooms and displays frequency biases for each country in real time. This unified overview makes it easier for TSOs to work together more effectively in order to control frequency biases. The Convergence test platform is the tool for grid studies from D-2 to real-time, used both by RTE and CORESO. The theoretical availability rate of the Convergence servers for D-2 to real time activities was 99.94% (100% in 2013). In 2014, the Convergence application was migrated over to the main Datacentre. The new infrastructure, together with the parallelisation of applications, should improve the system's performance; in particular, calculation times should be reduced which will improve the sluggish operation that some users have experienced. To help operators update studies in the event of significant changes relating to hypotheses or results in the Coordinated Short-Term Studies (ECCT) process, the SISTER operator support project brought the COMPARE module online in September The Safety Telephone System (STS)-V2 was deployed across all Operation Centres in July 2014, improving reliability of operational communications.

7 Page: 7/11 In order to render its information system more secure, in 2014 RTE successfully implemented its project to re-insource secure remote and external access infrastructure (RIADES) and to bring its Operational Security Centre (COrS R) online. The self-assessment procedure in relation to standards and reference frameworks was renewed, with particular focus on reference frameworks developed by the ANSSI (French IT security agency). Within the framework of the joint approach adopted by RTE and ERDF in January 2013 which looks at exchanges on operation principles at the interface between the two networks, particularly in terms of managing reactive power, several fruitful tests were carried out in 2014 by the Operation Centres and the Regional Control Agencies (ACRs). The Vendée Smartgrid project is one example of the work being jointly carried out. For winter , RTE renewed its tests in Brittany in order to mobilise local load curtailment over the Balance Mechanism, the aim being to secure electricity supplies in Brittany during periods of operation constraints. Following this new call for tenders, four stakeholders were selected, providing capacity of 62 MW. This innovative approach is a means of encouraging the participation of smaller capacities of 1 MW and higher. 11 MW of capacity were brought online in December. And as of 1 January 2014, companies can use the new NEBEF mechanism (Notification of the Exchange of Curtailment Blocks) to optimise the curtailment valorisation directly on the market. 5- System structure and design rules a supply-demand balance which may be subject to stresses in the event of a period of intense cold in the winter publication of RTE s fourth ten-year network development plan allocation of second off-shore wind generation lot In 2014, RTE invested a total of 1374 billion, including 1243 billion in network equipment. The main investments across the grid were largely to do with integrating renewable energies, finalising the new HVDC link between France and Spain and securing electricity supplies in a number of regions, including Provence-Alpes-Côte d Azur and Vendée. Some of the more significant structural changes made in order to ensure reliability across the VHV network include the bringing into service of the 400 kv electricity substations in Oudon for the completion of the Cotentin-Maine project, and Galoreaux in the Pays de Loire region (intended to secure electricity supply across western France and the southern part of the Pays de la Loire region), as well as testing of the PACA safety net" and the HVDC link between France and Spain. In the baseline scenario selected, the provisional forecast for 2014 shows a 900 MW capacity deficit in the event of a period of intense cold during the winter of This could reach 2 GW for the winter of This deficit confirms the trend that RTE has seen over the last few years and illustrates the effects heralded by the European environmental directives on fuel oil and coal-fired power plants i.e., nearly 6 GW of closures in 2014 and These assessments will be updated in 2015, when uncertainties in relation to several hypotheses are released (refurbishment and normalisation of fuel oil-fired power plants, resumption of activity at combined gas power plants). The capacity mechanism should serve as a means of securing the supply-demand balance of the grid during peak consumption periods starting in winter with the help of price signals that should encourage players to take favourable decisions during stretched periods. In 2014, RTE published the fourth edition of its 10-year network development plan, produced on an annual basis. This plan lists all the network development projects that RTE proposes to undertake and bring into service within the next three years; it also presents the main electricity transmission infrastructure to be developed over the next 10 years. This plan is based on medium and long-term analyses of energy consumption and of the energy mix evolution in France and Europe derived from the provisional forecast plan. It supplements the Ten-Year Network Development Plan (TYNDP), as well as various European regional plans published by ENTSO-E. In May 2014, the second offshore wind generation lot was allocated two farms with total generation capacity of 500 MW each. It was allocated following a call for tenders to a new consortium of

8 Page: 8/11 producers. As is the case for the first lot, RTE is in charge of performing the studies and then undertaking the work to connect the farms up to the Public Transmission Network. 6- Contribution to reliability of human resources and organisations dynamic appropriation of the APGP (Improved Performance through Professionalism) approach implementation of initiatives to prepare future skills adaptation of organisations (performance control cell, code deployment committee) In 2012, RTE introduced an "Improved Performance through Professionalism" approach. In order to support this approach, in December 2013 the Executive Committee signed a trust charter entitled "Transparency for Progress". In 2014, the spirit behind this charter was applied to regions throughout France via awareness-raising days organised by the national human factor representative. The effects of this management can be seen in the culture that has emerged within RTE in relation to this issue: numerous awareness-raising initiatives and training programmes for analysing the human factor have been set up in regions throughout the country aimed at a wide audience, and increases have been recorded in the number of events declared. In terms of training and skills, the future requirements of the Operation and Maintenance division including the development and maintenance of rare expertise were subject to a forward-looking analysis in RTE also introduced accelerated training procedures for employees joining the maintenance teams, the aim being to ensure their full understanding of the core skills that their profession requires and mitigate against the skills drain caused by the high number of people who will be retiring over the next few years. As usual, RTE arranged sessions in regions throughout France for sharing information about reliability with its suppliers and clients. Discussions were also held about specific operational situations and shared training programmes were set up with our European partners, including ELIA, NGIC, REE, Swissgrid and STATNETT. The annual meetings with producers served as an opportunity to discuss the performance of generating units in relation to adjustments and contracted ancillary services for frequency and voltage control. They were also used to discuss periodic re-energising tests, as well as other faults and incidents that had occurred during the course of the year. Two new entities were set up for management and organisational purposes: (i) the "Performance Monitoring unit which will monitor the performance of producers and suppliers of operating curtailment capacity and check their performance over time, as well as their compliance with the initial connection clauses; (ii) the code deployment committee whose task is to supervise RTE s initiatives to bring its operations into compliance with future European grid codes also saw a significant number of crisis management exercises, a number of which were used to test interregional and national coordination. Several served as opportunities to test Continuity Plans and Recovery Plans, particularly for remote control activities. A national crisis management exercise involving the National System Operating Centre and the Toulouse and Marseille Operation Centres was used to test the current structure of RTE s ORTEC plan its Crisis Organisation. 7- Evolution of the reliability reference framework and of contractual rules experimental contribution of Public Transmission Network consumers to the frequency ancillary services new contract: seven suppliers of rapid and complementary reserves RTE updated and published several articles in the Technical Reference Documentation. As far as reliability in particular is concerned, these articles were about frequency / power control, voltage and reactive power constructive capacity control for generating facilities, Q/U diagrams, ancillary service rules and operations agreements for generating facilities, as well as a template for constructive capacity specifications. In the coming years, these will help RTE to standardise the overview that it has of actual performance across all of the generating units connected to the Public Transmission Network, no matter how old they are, what their capacity is and what their line is.

9 Page: 9/11 As far as the inter-tso reference framework is concerned, a project to rewrite the 8 policies was launched in 2013, the aim being to integrate at European Continental level, the network codes currently awaiting approval. This project is also an opportunity to review the structures of several policies and to reformulate any requirements which have been found to be inappropriate. RTE is playing a role in all of these projects and chairs the policy 4 "Coordinated Operational Planning" project. In 2014, RTE self-assessed its compliance with policy 8 (control centre training). This helped flag up shortcomings in the way in which experience is shared between operators in France and Switzerland: the holding of joint training and workshop exercises will help improve the way experience is shared. An ENTSO-E study published in March 2013 highlighted the risks that would be incurred by the European system in the event of a massive tripping of renewable generation. This study was updated following an inventory carried out in June 2014 of TSOs. On the basis of this report, in November 2014, ENTSO-E published a "position paper" detailing the current situation and formulating recommendations for Member States. A joint project with ERDF has been expanded to include ADEeF (Association of Electricity Distributors) and is currently under way in order to develop a national solution in response to recommendations both for high frequencies and low frequencies. As far as frequency ancillary services are concerned, involvement in primary frequency control was opened up to consumers and aggregators as part of an experiment on 1 July As of March 2015, the consumption sites connected up to the Public Transmission Network involved in this test supply 9% of French primary reserve approximately 50 MW. And in December 2014, RTE implemented a process enabling players on the market to exchange reserves by mutual agreement, thus optimising the cost that RTE has to bear in order to compose its reserve. As far as voltage Ancillary Services are concerned, 2014 saw the carrying out of preparatory studies designed to: (i) examine the Public Transmission Network's reactive power requirements for the midand long term, (ii) update the map of sensitive areas for low and high voltages, (iii) analyse current factors preventing players from being involved in voltage Ancillary Services and put forward suggestions for improvements in order to tackle this, (iv) assess, as objectively as possible, the costs borne by players for being involved in the supply or absorption of reactive power, particularly for power electronic devices. As far as the balancing mechanism is concerned, the rapid and complementary reserves contract that came into force on 1 April 2014 was completely overhauled in order to integrate new players and enable more stringent checks from RTE on the effectiveness of power delivered in real-time. The call for tenders that was issued on this new basis made it possible to subscribe to the rapid and complementary reserves that RTE needs from seven suppliers. The implementation of this new contract is evidence of RTE s commitment to reacting effectively to issues to do with supply-demand balance, encouraging the development of all types of flexibility, implementing measures to increase performance and to supporting this implementation in order to guarantee the system's reliability. 8- Reliability beyond RTE As far as network codes are concerned, the "Capacity Allocation and Congestion Management" (CACM) code relating to rules covering access to interconnections was approved by Member States in December 2014 and should be published in June 2015 in the European Council's official bulletin. This code, which is key to the completion of the integrated electricity market, contains reliability-related data in that it defines the methods coordinated among TSOs for calculating the capacity that can be allocated to the market. The European Council has set itself the aim of getting all codes approved by Member States by the end of The third edition of the TYNDP (Ten-Year Network Development Plan) was published in December Published every two years, this plan is essential for sharing an overview of all forthcoming network developments at European level, the aim being to work towards a safe European electrical system and optimise the use of generating sources. In compliance with European Regulation 347/2013 which amends the regulatory framework for developing infrastructures used to share energy across Europe, the development projects for the European network which are outlined in the 2014 TYNDP have been subjected to a unified Cost Benefit Analysis.

10 Page: 10/11 The added value provided by these regional coordination centres is already well integrated and is constantly being extended over time. At the same time, the areas in which various centres (CORESO, SSC, TSC) cooperate are being strengthened, thus improving the reliability of the whole European network. Effectively managing the potential of interconnections involves coordinating with other TSOs in Europe in order to operate our infrastructure. This is made possible by CORESO, the regional coordination centre. It provides partner TSOs with an extended overview of the electrical network, beyond each one's borders. Each year, CORESO helps detect and address difficult and varied operational situations; it puts forward effective cross-border actions designed to avoid costly national redispatching initiatives. As in previous years, RTE s national and regional operators took part in discussions with their European counterparts in order to further share their reciprocal knowledge and understanding of each other's cultures, as well as the rules in force and the tools used. They also took part in joint exercises covering the management of disturbed situations (common training) based on simulations of actual networks. In 2014, two such sessions were held in Madrid. Within the framework of common training initiatives for European TSO operators and CORESO, two "real-time" sessions bringing together operators from the National System Operating Centre and TSOs across the Central Western European zone were held in As far as R&D and major European projects in which RTE is involved are concerned, the following should be noted for 2014: (i) initialisation of the "DC Networks" project, the aim of which is to ensure consistency and manage R&D initiatives in this area and to supervise three doctoral theses; (ii) the launch of a new European project "BEST PATHS in which RTE is managing a demonstrator which will lead to the interoperability of multi-supplier converters being tested on the SMARTe platform; (iii) the acquisition of Siemens CSPRs (Reactive Power Synchronous Compensators), together with remote MMIs for forecasting via studies within the perimeter of the SMARTe project, rapid dynamic phenomena and developing methods for managing these facilities; (iv) delivery of various functional components for the itesla project and preparation for tests and operation across the PACA region; (v) the first results of the SmartLab project on the mechanical resistance and ageing of equipment and the launch of a simulation tool for asset management strategies. 9- Reliability audits The Reliability Audit Task Force regularly carries out detailed audits intended to ensure the system's ongoing reliability from a number of different viewpoints. Three audits were conducted in 2014 focusing on a number of different areas: (i) the impact of recent reactive energy compensation installations on the control of the electrical power system, (ii) ROSE telecoms services (Optical Security Network) for operating the electrical power system, (iii) preparing to manage tomorrow's network. The various action plans for each of these audits are in the process of being carried out over a period of 2 years. Conclusion The results obtained in 2014 are evidence of a satisfactory level of reliability levels for RTE's operations in a context that is globally positive (weather, consumption, availability of generation and network equipment, etc.). However, these results should not mask the risk of less favourable conditions being encountered over the next few years particularly as far as supply-demand balance is concerned over the next two winters in the event of periods of intense cold. These results are, needless to say, the fruit of work that has been done both internally and externally with our partners over a number of years. They emphasise the fact that ensuring system reliability is an ongoing task that is underpinned by scheduled initiatives implemented over time across an extremely wide scope and involving expertise from a number of different areas. The numerous projects that are currently under way will ensure that the network continues to be reliable, while at the same time making it easier to integrate European markets and increasing the technical and economic performance of the interconnected electrical power system. In addition to the availability and reliability of tools and equipment, reliability in future years will be contingent on more coordination at European level, higher levels of flexibility, more players (and so stiffer competition and

11 Page: 11/11 greater economic efficiency), and the system being operated closer to its limitations, the corollary being increased monitoring and checking from RTE. The key issues that have been highlighted in this 2014 report involve the need to continue with initiatives that have already been implemented at various different levels over the next few years. In particular these include: continuing to improve the performance of the Convergence analysis tool in 2015, continuing within the framework of the SISTER /ECCT project to implement a support system for operators, consolidating and adapting tools used to manage demand-supply balance to ensure that they meet future requirements, anticipating the coming into force of European code grids, continuing discussions and tests with our partners who play a significant role in ensuring the system's reliability (reactive power of generating units, controlling reactive power at the interface between the Public Transmission Network and the Public Distribution Network, etc.), continuing to expand the assortment of players involved in order to increase economic efficiency and flexibility in managing short-term demand-supply balance (load curtailment, asymmetrical frequency ancillary services, etc.), continuing work already in progress to consolidate mechanisms for systematically checking the commitments and performance of players in order to ensure that reliability is properly managed in new and changing configurations, ensuring the effectiveness of companies' maintenance / renewal initiatives in order to reduce faults on reliability-sensitive equipment (switch gears, differential busbar protection devices, etc.), making progress at French and European level in understanding and controlling frequency biases, working on predicting them, making progress at French and European level on assessing and reducing the risks of massive generation tripping. All of these initiatives will help ensure the system's operational reliability in the long-term. This is RTE's fundamental task and assuming responsibility for it benefits all its clients.