The Austrian electricity grid forms the foundation for the transport of electrical energy from power plants to end consumers. It consists of seven grid levels, which differ in their functions and voltage levels, and are organized by transmission and distribution system operators. This article provides an overview of the different grid levels and their respective roles in the electricity grid.
The Electricity Grid#
The Austrian electricity grid constitutes the basic infrastructure for the transmission of electrical energy. It transports the electricity generated in power plants to substations, from where it is further distributed and finally made available to end consumers. The organization of the grid is carried out by transmission or distribution system operators, depending on the grid level.
The Austrian electricity grid is divided into seven grid levels, which differ based on their voltage levels. There are four voltage levels (grid levels 1, 3, 5, and 7) and three transformation levels (grid levels 2, 4, and 6), which enable transitions between the voltage stages.1 2 The illustration below shows the extra-high voltage grid operated by the transmission system operator APG.3
Fig. 1: The Austrian extra-high and high voltage grid © 2024 Austrian Power Grid AG 3
Voltage Levels#
Extra-High Voltage Level (Grid Level 1)#
The extra-high voltage level includes lines with voltages of 220 kV and 380 kV. These enable low-loss transport of large amounts of energy over long distances and facilitate international electricity exchange. Large power plants, such as major hydroelectric plants, feed their generated energy into this grid level.1
High Voltage Level (Grid Level 3)#
In the high voltage level, electricity is transported at a voltage of 110 kV. It serves the first large-scale distribution to supply cities and major industrial facilities. Medium-sized power plants feed into this level, including the majority of renewable energy plants.2 4
Medium Voltage Level (Grid Level 5)#
The medium voltage level operates at voltages from 1 kV to 36 kV and supplies individual city districts and towns. Smaller, urban power plants also feed into this level.2 3
Low Voltage Level (Grid Level 7)#
Households and smaller commercial enterprises receive their electricity via grid level 7, which operates at 400 to 230 V. Small PV systems and other decentralized generators also feed into this level.1 2
Transformation Levels#
The transformation levels ensure that the voltage is stepped down from a higher to a lower grid level using substations. Grid level 2 connects the extra-high voltage level with the high voltage level, while grid level 4 forms the transition from high to medium voltage. In grid level 6, the voltage is transformed from medium to low voltage, making the electricity usable for households and businesses.2 3