Grids: For reliable electricity supply

How it works

The electricity flows through the lines of the power grid like water through a pipe. And just as water is forced into a water pipe by a pump, a wind turbine or a gas-fired power plant, for example, generates a voltage that lets the current flow through the grid. More precisely, electrons, tiny electrically charged particles, move through the lines. Their path to the socket leads them through a long power grid at various stages (for more information, see: The path of electricity). The path consists of a supra-regional transmission network as well as regional and local distribution networks. Transformer stations in so-called substations connect these grid levels with each other. 

Our assets

They are the lifelines of modern society: Our grids bring electricity from power plants to consumers. The path runs through the transmission and distribution grids. Axpo maintains its own grid infrastructure in Switzerland and uses its distribution grids to connect the transmission grid of the national grid company Swissgrid with the distribution grids of its customers.

Axpo supplies electricity to the entire northeastern part of Switzerland, the Principality of Liechtenstein and parts of the cantons of Schwyz, Zug, Grisons and Valais with its grids, which are a total of 2200 kilometres long. The area with three million inhabitants and a prospering economy covers a third of Switzerland. Up to 3200 MW of power is supplied to customers.

Axpo's grid infrastructure, with its supra-regional distribution grids, primarily covers high voltage. On the one hand, it is connected via its own distribution networks to the transmission network of the national grid company Swissgrid, and on the other hand it is also connected to the distribution networks of customers, i.e. cantonal and regional electricity companies such as the electricity plants of the Canton of Zurich (EKZ).

Power lines: overhead and underground

Electricity is transmitted via overhead lines (above ground) or underground cables (below ground). For the conversion of its distribution network, Axpo relies on a comprehensive weighing of interests with regard to various criteria such as spatial development, cost-effectiveness, environmental compatibility and technology. As a general rule, the lower the voltage, the more frequent the wiring. As the voltage increases, the complexity of the construction and operation of cable lines increases. Axpo's 2200-kilometer distribution network consists of 82 percent overhead lines and 18 percent underground cable lines. Axpo is open to both technologies and uses the one that makes the most sense on the basis of objective criteria.

Reliable and efficient - around the clock

Security of supply has a high priority for Axpo. This means ensuring that the desired amount of energy at the required quality is available at all times in the entire electricity grid at reasonable grid usage prices. To achieve this, electricity grids must be operated, monitored, maintained and, if necessary, expanded or renewed. Thanks to prudent investments in the grid infrastructure and the broad expertise of its employees, Axpo achieves high grid stability and reliability. And that's not all: Axpo offers the best conditions for the use of its networks throughout Switzerland. 

Axpo's energy and grid control centre in Baden ensures the operation of its grids. The energy and grid control centre is the brain of Axpo's entire electricity grid. It controls and monitors the grid and the power plants around the clock, 365 days a year. This is where all the information from dozens of power plants and power grids converges. Some 60,000 messages and 25,000 measured values are processed online and rendered into 3,000 images for the operators.

Increasing electrical output

Axpo strives to maintain a high level of supply security. The growing demands of the energy future with the expansion of renewable energies and developments in society and the economy must be taken into account. Axpo is making sustainable investments in its grid, and gradually increasing grid voltage from 50 to 110 kilovolts. This makes the power plants more efficient and reduces losses by 75 percent. As a result, customers and the entire region benefit from a modern, future-oriented and reliable energy supply.

The path of electricity

Water, wind, sun or nuclear power becomes electricity. It flows through networks, is converted and ultimately gets the radio, TV, washing machine or cooker running via the electric socket. This is the path of electricity, simply explained.

Electricity grids bring electricity from the power station to the consumers. The route leads via the transmission and distribution grids. On the way to the socket, the electricity has to be converted to the required voltage. This takes place over several stages, so-called grid levels:

  • Extra-high voltage or transmission grid with 380/220 kilovolts
  • High-voltage or supra-regional distribution network with 50 to 150 kilovolts
  • Medium-voltage or regional distribution network with 1 to 30 kilovolts
  • Low-voltage or local distribution network up to 1 kilovolt

The national grid company Swissgrid operates the Swiss transmission grid and ensures energy transport over long distances. Axpo plays an important intermediary role here: Its distribution grids (110, 50 and 16 kilovolts) connect Swissgrid's transmission grid (220 and 380 kilovolts) with the distribution grids of Axpo partners - the cantonal, municipal and municipal utilities. 

Digital transformation & innovation

The digital transformation and innovation are an important basis for a modern energy supply. This opens up new possibilities for intelligently meeting the high demands of the energy future. Axpo is already using digital technologies in its power grids. While data is digitally processed for the service and maintenance of systems and a drone supports aerial line inspections, an extensive cockpit helps to analyse and visualise network data. New digital tools can also be used today to quickly assess supply security and immediately initiate measures for network optimisation. Digitalisation, however, goes a step further for the future. Information flows between network operators and manufacturers and between electricity suppliers and consumers will be automated, processes simplified and resources used more efficiently. Whatever the digital future of grid installations may look like, Axpo's top priority continues to be a reliable, efficient and environmentally friendly electricity supply. 

Find more information on the digital transformation of Axpo's network infrastructures here.

Drones for the grid

They buzz overhead and sometimes distrub the relaxing coffee break on the terrace: Drones are widely used today. At Axpo, they make sense in the grid area to maintain a reliable electricity network. Drones make it possible to efficiently inspect approx. 8000 power masts and our lines, which are around 2200 kilometres long. Their impeccable condition is a prerequisite for the safe and reliable transport of electricity.

To date, only overhead linesmen have regularly monitored the condition of masts and conductor cables. Now they get support from the air. With the drone, system inspections can also be carried out when lines are switched on, which increases the availability and saves costs. UAVs (unmanned aerial vehicles) can also take high-resolution photos from optimum viewing angles - even in hard to access locations. The photos help to assess any damage and to define repair measures. 

And by the way: Drones are also available to other companies as a service. Read more here.

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