Mini-series: “Stronger together” – The synchronous grid of Continental Europe

The NordLink connects Norway and Germany with “green” energy from water and wind, which we learned about in the previous part of our mini-series. However, there are other alliances for a better supply of electrical energy in Europe and the world. The so-called synchronous networks are large-scale, spatially adjacent and electrically connected power grids that link a large number of power plants with consumers. In this way they represent a contrast to the island networks, which function autonomously.

The north-south line built in the 1920s represented the first step towards a synchronous grid in Germany. At the time of the Second World War, work began to extend high-voltage lines to Belgium, the Netherlands and France, thus laying the foundation for the first part of the European synchronous network.

The Central European synchronous grid is a close-meshed electricity network consisting of high-voltage and extra-high-voltage lines for the distribution of electrical energy, which extends across the whole of Europe. The foundation of the UCPTE (Union pour la coordination de la production et du transport de l’électricité) in 1951 created the basis for the common synchronous system in which the countries Austria, Belgium, France, Germany, Italy, Luxembourg, the Netherlands, Switzerland and France participated. Due to the liberalisation of the electricity market, the UCPTE was transformed into the UCTE (Union for the Coordination of Transmission of Electricity) in 1999. In the meantime, a number of other European countries, such as Greece, Poland and Croatia, have also joined. For decades, the UCTE was responsible for the coordination of operations and the expansion of the European network and supplied a total of over 400 million consumers.

The tasks of the UCTE were then taken over by the umbrella organisation of transmission system operators ENTSO-E (European Network of Transmission System Operators for Electricity) from 1 July 2009. However, the technical limitations of the synchronous grids and the former UCTE have remained unchanged, which means that synchronous grids in other countries cannot be directly connected electrically. One of the reasons for this is that it is not yet possible to cover long distances, for example over the sea floor. As a result, distant islands such as Iceland or Great Britain cannot be connected to the European grid and must maintain their own island grids.

However, there are also many advantages of synchronous networks, which is one of the reasons why they have been developed so much. A major advantage is that the local difference between supply and demand of instantaneous power can be better balanced within the synchronous network and less balancing power has to be kept available in relation to the total installed power. In addition, power fluctuations can be better compensated for in the short term by power exchange than by regulating the power plants alone. This significantly increases the reliability of the network as a whole.

In the next article we will look at what makes networks reliable and discuss the importance of “power quality”. morEnergy GmbH – the network experts.