Security of supply - Update


04-10-2012

Following the announcement that the nuclear power plants Doel 3 and Tihange 2 will not be recommissioned in the short term, questions are being asked about security of supply in Belgium.



As the transmission system operator in Belgium, Elia acts as an interface between power generators, suppliers and traders on the one hand and industrial customers and distribution system operators (who supply SMEs and residential customers) on the other.

In this context, Elia would like to clarify the respective roles of the market players:

  • The government, represented by the Minister for Energy, is responsible for national security of supply.
  • Power generators/suppliers are contractually obliged to supply electricity to their customers and are responsible for maintaining a balance between their generation and their customers’ consumption.
  • Elia allows market players access to its grid, including interconnections with neighbouring countries, and provides a range of services to maintain a constant balance between generation and consumption in the Belgian area.

As transmission system operator, Elia, which does not have generation facilities of its own, performs simulations to assess the potential impact of a prolonged shutdown of the Doel 3 and Tihange 2 reactors on security of power supply over coming winters.

Assuming that the unavailability of Doel 3 and Tihange 2 is confirmed, the simulations show that:

  • Belgium will become structurally dependent on imports during the winter peak in order to cover demand for electricity;
  • the interconnection improvements made by Elia will allow Belgian market players to source 3,500 MW of energy (the equivalent of 3.5 nuclear power stations) beyond Belgium’s borders;
  • the operating margins of the Belgian electricity system will become increasingly tight, and it is therefore essential to avoid the shutdown of further plants.

Furthermore, Elia must be prepared at all times to manage emergency situations so as to prevent, as far as possible, any interruption in power supply.

Two especially critical situations can arise:

  • an unexpected incident leading to a major imbalance between generation and consumption (cf. event of 4 November 2006): in this case, automatisms are used to reduce consumption temporarily, possibly resulting in a very brief interruption to supply for a small number of users;
  • a shortage (usually predictable), when local generation is insufficient to cover consumption, particularly at the peak time of the day (traditionally after sunset, around 6:15 p.m. in winter). In this case, specific measures are prepared in consultation with generators and the authorities:

1) Limitation of demand on a voluntary basis: asking citizens to change their habits to prevent an imbalance at the critical period of peak consumption.

2) Imposing binding or contractual measures on businesses and institutions: no illuminated signs at peak times, reduced refrigeration, and temporary interruption of certain industrial processes.

3) As a last resort, rolling out a load-shedding plan in agreement with the authorities.

In all cases, Elia will inform the authorities in advance and decide with them what information to convey to the population affected by these measures.

Further information can be found in the fact sheet detailing operation of the electricity market and grid.