Electricity balancing

Balancing mechanism and frequency ancillary services


Electricity is stored in very limited volumes. Generation must therefore be equal to consumption at all times.

RTE ensures this balance in real time, factoring in generation and consumption contingencies (weather, power generation availability, etc.). To maintain the supply-demand balance, RTE must have an adjustable power reserve available in real time for upward and downward balancing.

There are three types of reserves which can be successively applied:

  • Automatically activated reserves: the frequency ancillary services, which integrate frequency containment reserve and automatic frequency restoration reserve
  • manually activated reserves: the balancing mechanism composed of the tertiary reserve

Market participants liaising with power generation companies and consumers then make upward (increased generation or reduced consumption) or downward (reduced generation or increased consumption) balancing energy bids. These bids are defined by a set price and terms and conditions of use. RTE then activates these bids according to their cost-effectiveness and constraints. The principle of this selection is based on common merit order.

The future of balancing

Establishing the internal market in electricity is a strong policy ambition for the EU Commission. Its aim is to facilitate trade in electricity between Member States to benefit from the most competitive resources in Europe at any given time. It is based on several guidelines determining a set of common rules.

Among these regulations, the Guideline on Electricity Balancing defines the main axes of the transition to a supply-demand balance market which is fully integrated on the European level. This Guideline establishes the technical, operational and market terms and conditions for the procurement of balancing capacity, activation of balancing energy and their financial settlement.

In anticipation of the entry into force of the Guideline on Electricity Balancing in December 2017, European system operators have undertaken measures to implement it at national levels. In France, this has been through the development of market terms and conditions for frequency ancillary services, scheduling, the balancing mechanism and the balance responsible party system. It incorporates several projects (relating to the various balancing processes) with the participation of several European countries: the TERRE, MARI, and MARS projects, the FCR cooperation and the IGCC imbalance netting cooperation.

Additional information

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