Report on the balancing mechanism: September 2014

Electricity is stored in very limited volumes. At any time, generation therefore has to be equal to consumption. RTE ensures this balance in real time and factors in generation and consumption contingencies (risks of severe weather, power generation capability, etc). In order to maintain supply-demand balance, RTE has to have a power balancing reserve available in real time for upward and downward adjustment. There are three types of reserves which can be successively deployed. Once the primary and secondary reserves (services controlled by RTE so that power plant generation can be automatically increased or decreased) have been deployed, RTE notifies the generation companies and consumers connected to the grid that the planned operating program needs to be changed very rapidly. This is the role of the balancing mechanism (or tertiary reserve) set up in 2003. The market participants liaising with the power generation companies and the consumers who can do so then make upward and downward bids and notify RTE of their technical and financial conditions. RTE then selects these bids according to their cost and requirements. This mechanism therefore enables the most effective bid in technical and economic terms to be selected. It also makes it possible to resolve congestion on the grid. This phenomenon occurs, for example, if an electrical line is damaged and electricity flows are distributed over neighbouring lines. The monthly reports on this balancing mechanism designed and set up by RTE contain the following information: - summary of the indicators published by the balancing mechanism operation committee, - characteristics of the balancing entities the most deployed during the month, - results of the adjustment-difference accounts up to month M-3, - costs for resolving congestion on the grid up to month M-1, - volumes activated under the terms of the reserve trading contracts concluded between RTE and other TSOs, - reliability rate of the provisional indicators posted on the RTE web site in real time, - reliability rate of services. This report presents the information from September 2014