Power System Reliability Report - RTE

R-AUDIT-SG-DAR-MAS-11-2011/022010 Reliability ReportPage : 7/408 juillet 2011In summary,From an operation standpoint, 2010 was marked by tense situations during cold spells that RTE wasable to manage effectively, but which required issuing safeguard orders more than 15 times. Thesedifficult situations, which reoccur from year to year despite regular improvements made in thereinforcement of compensation means and operational management, reveal structural weaknesses inthe location of generation facilities in the West and South-East regions, as well as the impact of thegrowing thermosensitivity of consumption.RTE‟s ability to handle severe meteorological incidents, as already proven in previous years, wasconfirmed during the management of windstorm Xynthia and the flooding in the Var on June 15 th .The incidents that affected electrical system reliability assessed in terms of ESS with a level A orhigher, had increased significantly in 2009. 2010 is characterized by a return to the average trendfrom 2005-2008, even though the number of ESS level A and B remains higher, due to the increase inESS A recorded during tense operating situations during cold spells. Vigilance with regard to reliabilityremains a timely issue and hence RTE must keep up its efforts to fully exploit feedback and todisseminate its lessons, even though, in a longer term perspective, we can underscore that thenumber of ESS level B and higher recorded since 2004 is significantly lower that at the start of theprevious decade.Some points of potential risk stand out in this reliability report: the difficulty in making headway in thereduction of occurrences and the consequences of human errors, some of which may be important interms of reliability; the potential vulnerability of operations to data errors and the control of regularlyadapted parameters; the persistence of lasting reactive production capacity limits affecting a certainnumber of units, even though in-depth discussions with the concerned producer made it possible inearly 2011 to define a progressive management process to return to contractual capacities in the nextfew years.As a counterpoint, significant evolutions were made to improve reliability and regularly improvingoperating and control modalities, adapting them to an ever-changing environment: the revision of thefundamental rule of reliability – the N-k; introducing a new method to determine overload temporarycurrent levels to release additional operating capacities; noteworthy improvements in day ahead studymethods, in particular for very tense situations; reinforcement of events feedback.Given these evolutions, we must also ensure that operational teams have enough time to fullyassimilate the changes, especially since the tools themselves are also changing.Finally, like in 2009, progress was once again made in coordination at a European scale, including theincreasingly important role taken on by CORESO in operational management and the evolution incalculation methods of capacities available to the markets, in the framework of the implementation ofday-ahead market coupling in the Europe Centre-West region.********************************************************************Copyright RTE. This document is the property of RTE. Any communication, reproduction, publication even partial is forbidden without the express written authorisationElectricity Transmission System operator (RTE)