New lines of defence: how interconnectors keep the lights on

The report argues that interconnectors are critical for European energy security, having prevented three major blackouts in the last five years and providing a lifeline to Ukraine and Moldova during Russian aggression. It highlights that 55% of Europe's power system remains at risk due to limited import options, with Spain, Ireland, and Finland being particularly exposed. The document also details the vulnerability of infrastructure to sabotage, citing nine incidents in the Baltic Sea, and calls for accelerated deployment of new capacity and strengthened security measures to protect the grid from hybrid warfare.

• Interconnectors prevented three major blackouts in the European Union over the last five years, including two potential blackouts in Poland in 2020 and 2021.
• In Poland, interconnectors were critical during a May 2021 substation malfunction at Rogowiec, where flows from neighboring countries reached 4.5 GW to absorb a frequency drop, and during a June 2020 event where 3 GW of power was imported to prevent a blackout following a 5.7 GW generation loss.
• Interconnectors were essential for restarting the Iberian power system following a massive blackout on 28 April 2025 that affected approximately 60 million people, with the first France-Spain line reenergized within 10 minutes.
• 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.
• Interconnectors provided critical security for Ukraine and Moldova during Russian aggression; Ukraine achieved emergency synchronisation with the European system in three weeks in 2022 and imported 4 TWh of electricity in 2024.
• Moldova's energy security was supported by interconnectors with Romania after Russia stopped gas supplies to its largest power plant on 31 December 2024, forcing the country to source up to 62% of its electricity demand from Romania.
• 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 and enabled by links such as LitPol Link, EstLink, EstLink 2, and NordBalt.
• European energy infrastructure is increasingly targeted by sabotage and hybrid warfare, with nine recorded incidents of damage in the Baltic Sea since 2022, including the EstLink 2 power cable which saw a 27% reduction in Estonia's import capacity.

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} }