Engineers join forces
in the NCC

At Elia’s National Control Centre, System Engineers, Close-to-realtime Engineers and Market Engineers monitor the transmission system day and night. Each has a specific task; together they keep the lights on in Belgium, and even in Europe.

At Elia’s National Control Centre (NCC) in Schaerbeek, the dispatchers monitor the transmission system day and night. They continuously keep production and consumption in balance and ensure that the grid is not overloaded at any time. That sounds simple, but in reality it is quite complex. And with the rise of renewable energy, which is difficult to predict and which requires a lot of new infrastructure, the task is only becoming more complex.

In recent years, many new dispatchers have therefore been recruited for the NCC, and their jobs have been split into three positions: that of Market Engineer, Close-to-realtime (C2RT) Engineer and System Engineer. The three types of dispatchers work around the clock in three shifts. There is one Market, one C2RT and one System Engineer present in the NCC at any given time.

“To keep our system in balance, production and consumption must first be perfectly coordinated,” says Thibault Tilquin. ‘We, Market Engineers, monitor that balance in real time. To this end, we are in contact with the Balance Responsible Parties (BRPs) and Balancing Service Providers (BSPs). These can be energy suppliers and traders as well as large-scale consumers. In principle, they keep their portfolio in balance, based on consumption and production forecasts.

But suppose it is colder than normal, and many people turn up their heating a degree, or there is just much more sun and wind than predicted, then an imbalance can arise. If an imbalance occurs, we use balancing products. These are a kind of corrective services, provided by companies or power plants that can increase or decrease their consumption or production.

In the event of a small shortage, the automatic balancing products come into action. In the event of a major deviation, for example when a gas-fired power plant fails, we manually activate a reserve capacity (see also box). We then ask the BSPs to increase or reduce their production. The next step is to exchange energy with our neighbouring countries. In the event of larger incidents, we initiate emergency procedures. Our task is to solve the imbalances as efficiently and cheaply as possible.’

In addition to the balance between supply and demand, the infrastructure along which electricity flows – the transmission grid – is also important. The System Engineer monitors the grid in real time, the C2RT Engineer maps out the situation in advance.

‘We will make our first analysis on D-2: two days before the real-time situation’, to enable the day-ahead European market coupling. These files are essential to ensure optimal allocation of energy resources and ensure competitive prices on the European market, says Morgane Rasneur, Close-to-realtime Engineer. ‘How much electricity will flow through which paths? Will the wind turbines produce a lot? What maintenance work is planned?

Once the market coupling on D-1 is completed, we make a prediction of the grid at D 0 based on the nominations resulting from the day-ahead market, weather forecasts, predicted load profiles and the Common Grid Model – a picture of the European high-voltage grid. We are already trying to solve problems that may arise by identifying the risks of congestion and overload on the Belgian grid, while coordinating with the neighbouring TSOs. The grid must be N-1 compliant: it must continue to function, even if an element unexpectedly fails.

Because the grid is constantly changing, the model is re-analysed every hour of D 0 based on the most recent information received to provide the most realistic picture possible to colleagues System Engineers, who will continue to monitor the grid in real time.’

‘As System Engineers , we keep an eye on three parameters in real time,’ says Gilles Daems. ‘The tension on the grid to begin with. In the evening, when many people are cooking, watching TV, turning on the radio… the tension decreases. At the weekend, when there is less consumption by industry, it increases. We try to keep that tension constant.

In addition, we monitor the flow, the flows. They should never exceed a certain limit. The tricky thing about electricity is that it is difficult to store, unlike energy sources such as gas. The electricity must always be able to flow. The flow always looks for the fastest way. The only thing we can do is modify that path via phase-shifting transformers or by disconnecting connections in subtations, for example. A third parameter that we monitor is the short-circuit power: the power that makes it possible for protections to react as quickly as possible in the event of a short circuit. This parameter indicates how stable the grid is in a certain place.

In addition to monitoring those parameters, we also intervene if something happens. For example, when a crane hits a cable, the grid must not be overloaded. Otherwise, a snowball effect can occur. In 2006, things went wrong with a cruise ship that sailed under a high-voltage line in Germany. A short circuit switched off that line, which overloaded another line, which in turn switched off automatically. In the end, large parts of Europe were without power for two hours.

Occasionally we have to take unpopular measures, such as unplanned cancellation of maintenance. But when we ask for something like that, we always have good reasons for it. We don’t want to leave our country or even Europe without power!’

Is working at the NCC stressful, with all that responsibility? ‘It is, but I also like the adrenaline rush when you have to find a solution very quickly,’ says Thibault. ‘We are not alone, by the way. All dispatchers work very closely together.’

Gilles: ‘We share our knowledge, each from our experiences. We all have our own specific task, but it is only by joining forces that we can guarantee the safety of the grid. We not only consult when there are problems, we also talk to each other at quiet moments. About work, and about more general things. Sometimes we even cook together. That good atmosphere is really a big plus for me.’

Morgane: ‘We are a fairly young team, and there is no real office atmosphere here. Time flies by. I never look at my watch, or only to think: oops, is it that late already? What also makes this job so interesting: you are very close to the concrete, the reality. If there is one job that allows you to get to know Elia’s workings through and through, it is that of a dispatcher.’