ELIA 2009 ANNUAL REPORT — ECONOMIC REPORT
GRID OPERATION
Grid operation is central to Elia’s mission, and takes place across different timeframes, ranging from year- and day-ahead through to real-time operation, 24 hours a day, seven days a week. The national control centre maintains instantaneous balance between production and consumption and manages energy flows on the Belgian interconnected grid, in close collaboration with the transmission system operators from neighbouring countries. The regional control centres (in Merksem, Namur and Brussels) focus particularly on the quality of supply for industrial customers connected to the transmission system and for distribution system operators. They work in close partnership with the operational teams responsible for maintenance services. This operational mission increasingly re quires spe cialised skills, and now entails working in a European setting, since the Belgian grid is a subset of the West European grid and is synchronously interconnected with grids from Portugal to Ukraine. Following liberalisation of the internal electricity market, exchanges within this extended grid have continued to intensify, partly owing to the price differentials in the different national markets. The growing share of energy generated from renewable sources such as large offshore wind farms will increase the variability of energy flows within grids. The progressive introduction of intraday adjustment mechanisms will make it possible to meet the needs of these players more effectively by allowing them to align their production with their customers’ consumption throughout the day. This will result in greater variability of energy flows, which will require operational measures to be implemented in order to maintain a reliable and continuous supply.
To this end, Elia has put in place control instruments known as phase shifting transformers, which act like mixer taps and allow electricity flows to be distributed between a greater number of connections on the Central West European grid. These transformers, which are the largest in Europe, have been in service since the start of 2009 and are operated in close collaboration with the transmission system operators in neighbouring countries. Elia, together with its French and British counterparts RTE and National Grid, demonstrated its commitment to strengthening this European regional vision of grid operation by helping to establish Coreso, which began operating in February 2009. In its capacity as a regional technical coordination centre, Coreso assesses the risks of incidents on the Central West European grid over weekly and daily periods and in near real time. It warns the system operators concerned, including Elia, and proposes preventive measures in which phase shifting transformers play a vital role. For example, during the Lint incident on 21 July 2009, when the Belgian grid lost several 380 kV connections, phase shifting transformers enabled the operational security of the Belgian electricity system to be maintained between the moments the connections went down and the backup line was commissioned.
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