The European electricity system: Austria’s important bridging function
Nowadays, nearly all European countries work together to ensure secure electricity supplies. More than 30 states form the integrated system, and Austria is one of them. High-voltage lines transmit electricity over large distances, and national transmission system operators (TSOs) work around the clock to ensure that the system remains in equilibrium.
The shared, Europe-wide electricity network operates at a frequency of 50 hertz. But in spite of its size, the system is relatively fragile. Electricity cannot be stored in the grid, so the same amount of power has to be generated as is consumed at any given time. Even the slightest imbalance between the two – with too much or too little power flowing through the system – can cause electricity supply problems. In the event of deviations, TSOs take action to ensure that additional energy is provided or more electricity is consumed or stored.
New challenges: renewable energy
The task of maintaining balance in the Europe-wide system is becoming more and more difficult and complex. In the past, when there were only a relatively small number of large power stations, planning supplies to consumers across the various grid levels was straightforward, but today’s network is made up of numerous electricity producers, both large and small. The volume of power generated at these power plants is hard to forecast because it is dependent on weather conditions such as wind and sun. What’s more, the options for managing these facilities are limited.
Until after the second world war, cross-border exchanges of electricity in Europe were the exception – the various national systems operated differently and used different frequencies. Today, only the Scandinavian countries, the Baltic states, the United Kingdom and Ireland have their own integrated systems.
More and more electricity moving across borders
Initially, the European interconnected system mainly played a balancing role, as well as helping to quickly rectify outages. But the liberalisation of Europe’s electricity markets has seen electricity trading become increasingly important. On the free, liberalised market every customer can choose their supplier freely. In the past, electricity was purchased from only a handful of providers, which usually had their own generating plants, and then sold on to a specific group of customers. But thanks to liberalisation, customers have benefited from a sharp drop in electricity prices.
However, this development is posing problems for power grids, which now have to transport the energy that is traded on the international electricity markets. In combination with the trend towards renewables, this is opening up new opportunities but also creating new challenges for cross-border transmission. For example, solar panels along the solar power belt stretching through Baden-Wurttemberg and Bavaria produce far more electricity during summer than can be consumed at the place where it is generated. During the daytime, the surplus electricity is transported to pumped storage power stations in Austria and Switzerland. At night time, though, the flow is reversed, and hydroelectricity is supplied to consumers in solar-power-producing areas.
As part of the Europe-wide system, the Austrian grid is increasingly fulfilling an important bridging function, helping to transport power from the large wind farms in the north of the continent or solar power from the south. In every sense of the word, Austria is central to efforts aimed at enabling the whole of Europe to make the transition to renewable energy. Electricity can be produced where the necessary energy is available and consumed wherever it is needed.
This is another reason why Austria will have to make significant investments in its electricity networks in the coming years. Besides expanding distribution networks, the focus will primarily be on closing the gaps in the 380 kV loop. Large quantities of electricity can be moved over long distances using these ultra-high voltage lines, which will provide a high-performance link between the wind farms in the east of the country and the pumped storage plants in the west.