New lines of defence: how interconnectors keep the lights on

This report by Ember examines the critical role of electricity interconnectors in maintaining European energy security, preventing blackouts, and mitigating the impact of geopolitical conflicts and sabotage. It argues that expanding and securing cross-border grid capacity is a vital element of protecting European society against hybrid warfare and technical failures.

• Interconnectors have been instrumental in preventing or managing three major blackouts in the European Union over the last five years. Specifically, they helped avoid two potential blackouts in Poland: one on 17 May 2021 caused by a substation malfunction at Rogowiec, and another on 22 June 2020 following heavy rainfall that damaged coal supply lines.
• Interconnectors were essential for the recovery of the Iberian power system following the largest blackout in Europe's modern history on 28 April 2025, which affected approximately 60 million people. The system was restored around 16 hours later, aided by the reenergising of power lines connecting Spain to France and Morocco.
• Approximately 55% of Europe's power system is considered at risk due to limited emergency import options, defined as countries with three or fewer import directions and an import potential ratio of 25% or lower. Spain, Ireland, and Finland are identified as particularly exposed.
• Cross-border electricity exchange has been critical for Ukraine and Moldova during Russian aggression. Ukraine achieved emergency synchronisation with the European power system in three weeks in 2022; by 2024, it imported 4 TWh of electricity to offset the loss of 70% of its thermal generation capacity. Moldova similarly synchronised with Europe in 2022 and relied on Romania for up to 62% of its electricity demand after Russia stopped gas supplies to its largest plant on 31 December 2024.
• The Baltic States (Lithuania, Latvia, and Estonia) decoupled from the Russian power grid on 9 February 2025, a process supported by 1.2 billion EUR from the Connecting Europe Facility. This was enabled by connections such as LitPol Link, EstLink, EstLink 2, and NordBalt.
• European energy infrastructure is increasingly targeted by sabotage and hybrid warfare. Since 2022, nine incidents of infrastructure damage have occurred in the Baltic Sea, including damage to the EstLink 2 power cable by a Russian shadow-fleet vessel, which reduced Estonia's import capacity by 27%.

APA

Czyzak, D. P. (2025). New lines of defence: how interconnectors keep the lights on. Ember. https://ember-energy.org/app/uploads/2025/09/New-lines-of-defence-how-interconnectors-keep-the-lights-on-PDF.pdf

Chicago

Czyzak, Dr Pawel. New lines of defence: how interconnectors keep the lights on. Ember, 2025. https://ember-energy.org/app/uploads/2025/09/New-lines-of-defence-how-interconnectors-keep-the-lights-on-PDF.pdf.

Wikipedia

{{cite report |last1=Czyzak |first1=Dr Pawel |title=New lines of defence: how interconnectors keep the lights on |publisher=Ember |date=24 September 2025 |url=https://ember-energy.org/app/uploads/2025/09/New-lines-of-defence-how-interconnectors-keep-the-lights-on-PDF.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{czyzak2025new, author = {Czyzak, Dr Pawel}, title = {{New lines of defence: how interconnectors keep the lights on}}, institution = {Ember}, year = {2025}, month = sep, url = {https://ember-energy.org/app/uploads/2025/09/New-lines-of-defence-how-interconnectors-keep-the-lights-on-PDF.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }