Blackout disrupts Czechia

• 4 months ago (2025-07-07)
• David Flin

Distribution 146 Europe 1147 Transmission 223

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A large electricity outage struck parts of the Czech Republic on 4 July. The blackout affected large sections of Prague and several regions.

According to the Czech transmission system operator ČEPS , shortly after noon on 4 July a phase conductor failed on transmission line V411. The cause of the failure is still being investigated. The incident cut power to eight major substations, five of which were restored within a few hours.

Initial reports indicate that the failure of a phase conductor on HV line V411 triggered a frequency imbalance and partial system collapse. Investigators have ruled out a cyberattack as the cause. The specific cause of the rupture remains under investigation, with heat-related stress or equipment fatigue considered the most likely causes.

All repairs were completed by the early hours of 5 July.

Václav Skoblík of United Energy Commodities said the outage underscored seasonal imbalances—high solar output paired with low summer demand—and called for improved local storage and consumption flexibility.