A strong electricity grid is the basis for a secure power supply. APG’s trans-regional transmission grid consists of nearly 7,000 power lines that supply Austria with electrical energy. The grid connects the power plants to Austrian homes and businesses to form a widespread supply network incorporating the distribution networks of the individual federal states.
APG Grid Facts
- System length in km: 6,970 km
- No. of pylons: approx. 12,000
- Timetables / month for imports and exports: approx. 12,000
The flow of current in the electricity grid
Grid structure: the network levels
The power grid is made up of network levels comprising ultra-high, high, medium and low voltage levels. In APG’s trans-regional transmission grid, electricity is transported at the ultra-high voltage levels of 110, 220 and 380 kilovolts. Ultra-high voltage is necessary to enable electricity to be transmitted across great distances in the transmission grid. Electricity also flows at high and medium voltage levels in the nine regional distribution networks before continuing to the local low-voltage networks, where it comes out of the socket at 230 volts. The different network levels are connected via substations.
APG’s core task: maintaining the balance at 50 hertz
Around 75% of Austria’s electricity comes from renewable sources. Although hydropower has traditionally been the most important source of energy in Austria, wind and solar power have been heavily developed in recent years. The goal of the Austrian government’s new #mission2030 climate and energy strategy is for the country to be powered by renewables only by 2030.
Power generation is based on the principle that electricity supply must be matched precisely to electricity demand at all times. The measure of the balance between supply and demand is known as the grid frequency. To ensure an intact supply of electricity, the frequency of the grid must be maintained at exactly 50 hertz. The core task of APG is to keep the grid frequency at the 50-hertz level on a continuous basis.
Trans-regional electricity transport: APG connects wind farms in eastern Austria with pumped storage systems in western Austria
The structure of the electricity grid is similar to that of a road network. APG’s superordinate, trans-regional transmission network transports electricity from neighbouring countries to Austria and from Austria to its neighbours via all Austrian states. The subordinate distribution grids in the Austrian states are fed with electricity from the APG grid, which they then bring directly to the consumer. APG’s grid plays an absolutely crucial role in the transition to new forms of energy. It connects eastern Austria’s wind power plants and western Austria’s pumped storage power plants with Austrian consumers.
Substations: the hubs of the electricity supply system
To enable electricity to be used in homes and businesses, it first needs to be transformed, i.e. converted, to a lower voltage level. The voltage is converted at substations, of which APG operates a total of 63 across Austria. Transformers at the substations convert the voltage so that the electricity can continue on its way to the consumer. The switching stations located at the substations act as the hubs, or nodes, connecting the power lines by guiding the flow of energy. The APG grid, as the superordinate electricity transport network, is connected with all of Austria’s distribution networks.
A new transformator for a secure energy supply.
(Video in German only)
Helicopter dismounts a tower and rebuilds it.
(Video in German only)