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RTE's analysis of the supply-demand balance for winter 2011-2012

Source : RTE - DICAP 09/11/2011

RTE today publishes its analysis of the electricity supply-demand balance for the winter period 2011-2012.

RTE believes the risk of an interruption in supply in France to be moderate throughout the winter period. The electricity supply situation should be similar to last winter.

In November and December, given the heavy schedule of generating facility maintenance operations, imports could be needed, without exceeding the maximum import capacities of the French power network. Between January and March, the situation should become more satisfactory, with a net export balance.

In the event of an intense and sustained spell of cold weather, or a notable deterioration in the availability of generating facilities, in order to satisfy French electricity demand, suppliers would likely need to obtain large quantities of energy on the European markets, in addition to invoking demand response agreements with their customers. The levels of imports needed would remain compatible with the interconnection capacities between France and neighbouring countries.

To manage the impact of the shutdown of eight nuclear units in Germany, neighbouring transmission system operators have already begun intensifying their cooperation, vital for taking suitable joint operational measures to deal with the new situation facing the European power system this winter.

Every year, RTE conducts a prospective study of the balance between supply and demand for electricity for the coming winter period, covering the whole of mainland France. This time of the year generally sees high levels of electricity demand as temperatures fall.
The study is used to identify periods where the supply-demand balance comes under strain; it explores the measures that can be taken by electricity market players and RTE to avoid any interruption in supply during peak consumption periods in France.

This year, RTE has integrated novelty in the methodology utilized for the forecast analysis. In addition to the evening peak demand (at 7pm), the security margins calculated now also include demand levels in the morning. RTE believes that the management of security margins requires vigilance at all times of the day. The aim is to provide electricity market players with a more comprehensive and more accurate picture of the forecast situation.

For the winter period 2011-2012, the study is based on demand forecasts that are higher than actual figures for last winter, with demand expected to peak at 86,800 MW during the first week of January at the evening peak, assuming temperatures in line with seasonal norms.

Based on information provided by the generators in September 2011, the availability of the French generating fleet this winter is expected to be lower than last winter during the months of November and December, owing to a less favourable schedule of maintenance operations. From January and until the end of March, the arrival of new power plants and a more favourable schedule for shutting down generating units will result in higher availability of generating facilities over this period, as compared with the forecast outlook for last year.

Imports could therefore become necessary in November and December, to meet the demand for electricity in France and comply with RTE's network security criteria. To this end, suppliers would have to look to the European markets, in addition to invoking demand response (load reduction) agreements with their customers. The estimated level of imports needed could reach 3,500 MW in early December, to satisfy the technical security margin criterion for the evening peak demand.

From January onwards, the balance of exchanges should be positive with France exporting electricity.

In the event of an intense and sustained cold snap, forecast margins will fall, as French electricity demand is particularly sensitive to temperatures. Higher imports could be needed to satisfy electricity demand in France. If temperatures remain from 6 to 8°C below the seasonal norms over a sustained period, the level of imports would remain within the technical limit for the French transmission network.
In such circumstances, French market suppliers could invoke additional demand response clauses in their contracts with their own customers, or obtain supplies on the European market using the interconnection capacities made available by RTE.

RTE is alert to the impact of the shutdown of eight nuclear units in Germany. These shutdowns will require other generating facilities to be used. They will also lead to congestion (saturation) on the German network, particularly on the main transmission links running from north to south, and this may limit France's import capacity from Germany. This could in turn serve to tighten the supply-demand balance in France, especially in the event of a sustained spell of intense cold weather.
RTE is intensifying its cooperation with the German transmission system operators, to identify the conditions that would result in such limitations, and anticipate the measures needed to reduce the impact of this decision.

Any additional reduction in the availability of the French generating fleet would reduce forecast margins and raise the risk of an interruption in the electricity supply in the event of a cold snap.

All other things being equal, the rise in the demand acts to reduce the power system's operating safety margins.
Consequently, actions taken by individuals to manage or reduce electricity use can help to improve the country's security of supply.

Establishing and maintaining effective control of the demand for electricity is a major challenge for society, requiring a commitment by everyone, and it is an aim to which RTE intends to make a full contribution.

> See the analysis of the supply-demand balance for the winter period 2011-2012.