High Temperatures: Power Outages Not Always Due to Heat

While Vienna experiences power outages during heatwaves, the high temperatures are often not the sole culprit, according to Gerhard Fida, head of Wiener Netze. He explained in an ORF interview that while outages increase on days exceeding 30 degrees Celsius, the long-term average number of failures has not significantly changed despite more frequent heatwaves.

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Power fails in heat not solely because of high temperatures.

Fida elaborated that power failures during heat often occur when underground cables are already damaged, perhaps from prior construction work or excavation. Intense heat causes the ground to dry out, reducing its ability to dissipate heat. This leads to cables overheating. At weakened points, this added stress can result in a defect and subsequent power outage. Essentially, the heat often exposes pre-existing vulnerabilities rather than being the direct cause.

Similar situations are observed in rural areas like Styria. A spokesperson for Energienetze Steiermark stated that neither their network nor Energie Graz's network has seen a noticeable increase in outages directly linked to high temperatures. The primary challenge in these regions stems from weather events that follow prolonged heat, such as severe thunderstorms and strong winds, which can cause trees to fall on power lines, leading to interruptions.

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It becomes critical when an underground cable is already damaged, for example, by earlier construction work or damage from an excavator.

While power is usually restored in Vienna within 60 to 90 minutes, with an average annual outage time of about 14 minutes, the greater economic challenge lies in the long-term modernization of the power grid. The Austrian Court of Audit has criticized that the expansion of wind and solar energy is outpacing the necessary adaptation of grid infrastructure. Studies estimate that Austrian distribution grids require between 13 and 24 billion euros in investment by 2030 to manage the energy transition effectively.

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We record neither in the network of Energienetze Steiermark nor in the network of Energie Graz a noticeable increase in power outages due to high temperatures.