Power outages

Twice as often in summer: the “three Bs” are to blame

There have always been power failures, such as on the Ringstrasse.(Bild: zVg)

The temperatures in the city have been extremely high for weeks, and a few days ago the power outages increased. Is there a connection? The "Krone" asked the Vienna grids.

On Thursday evening, there were numerous power cuts in Vienna, for example in Döbling and Leopoldstadt. Klosterneuburg and Kritzendorf were also affected. A day earlier, the lights did not come on for a few hours in Floridsdorf (we reported).

What are the reasons?
But what are the reasons for the frequent power cuts? Does the extreme heat that has kept Vienna on tenterhooks in recent weeks have anything to do with it? According to a spokesperson for Wiener Netze, this is not the case. What is true, however, is that power outages occur more frequently in summer, with twice as many incidents in June, July and August than in the rest of the year. "However, this is due to the 'three Bs': diggers, trees and lightning. There is more construction work in summer, so excavators sometimes damage underground cables. In addition, there are more frequent thunderstorms that damage the overhead lines," the spokesperson continues. In turn, heavy rain could lead to transformer stations being flooded and lightning could damage pylons.

21 minutes

is the average time a Viennese is without electricity per year, which is a world record. In the rest of the country it is 24 minutes. Internationally, 150 minutes is already considered very good.

Grid equipped for air conditioners
However, the heat per se and the increasing use of air conditioners cannot harm the power grid. On the contrary: "We continue to see a much higher grid load in winter," explains Wiener Netze. This is because people spend more time at home and it is dark for longer. And even boilers and gas heating systems require additional electricity.

Short circuit due to dryness
What poses a problem for the power supply in summer, however, are longer periods of drought. This is because the groundwater level drops and with it the thermal conductivity of the ground. Put simply, the power cables overheat if the heat cannot be dissipated. This leads to a short circuit with the earth, the so-called earth fault.

Mostly the fault of others
In general, around 75 percent of power faults are caused by external factors such as thunderstorms. In summer, this proportion rises to 85 percent. There is no cause for concern in summer or winter: Vienna's grids are among the ten best electricity grids in the world.