System integration: The key to Europe’s energy trilemma
By Samantha Gross and Constanze Stelzenmüller, Brookings, 23 April 2026
Editor's note: This report is the sixth and final in a series on “Europe’s energy transition: Balancing the trilemma” produced by the Brookings Institution in partnership with the Fundação Francisco Manuel dos Santos. It was finalized for translation in mid-March 2026.
Executive summary
In a continually darkening geostrategic environment, energy security is becoming an ever more urgent goal for European policymakers. Russia’s invasion of Ukraine, recent U.S.-Israeli strikes on Iran, and a more coercive United States have Europe rethinking its external energy dependencies, almost all of which come with political baggage. Europe is also focusing on internal energy security—ensuring energy reaches consumers efficiently, reliably, and affordably.
Energy integration within the European Union (EU) and with neighboring states enhances all three aspects of the energy trilemma: security, affordability, and sustainability. When a member state faces disruptions to electricity or natural gas supply, cross-border transfers from neighboring states can smooth over supply and price shocks. As Europe continues its clean energy transition, greater integration allows better management of intermittent renewable electricity like solar and wind, reducing curtailment. Overall energy costs in the EU will also decrease, as more demand can be met by the least expensive available generation within the bloc and connected neighboring countries.
But there are economic and political challenges. Building and modernizing infrastructure like transmission lines and pipelines will require major funding from the EU and individual member states, along with private funding. The sheer scope of costs will lead to questions about who pays for what. Each country will have to give up some control of its energy system. Although system integration lowers overall energy costs, not every consumer will be better off all the time, and some energy producers face new competition from cheaper sources of energy elsewhere in Europe. These situations may create political constituencies against integration. Regulatory policies like the Emissions Trading System and the Carbon Border Adjustment Mechanism (CBAM) can stymie integration where it is needed most: in prospective EU member states.
In September 2025, European Commission President Ursula von der Leyen identified eight critical regional energy bottlenecks that span the EU and its periphery. Priority projects across the Baltics, the Balkans, the Iberian Peninsula, the Mediterranean, and the North Sea demonstrate how these challenges might be overcome by extending or deepening existing energy systems and connections and championing new decarbonization projects.
In today’s threat environment, supply shocks are the new normal. However, policymakers should not assume that this alone will sell the need for new cross-border projects. Rather, they will need to address social and economic costs from the beginning. With sustained political will, a more integrated European energy system could even become a driving force for European growth and competitiveness.
To download the full report, visit: https://www.brookings.edu/articles/system-integration-the-key-to-europes-energy-trilemma/?utm_campaign=Center%20on%20the%20United%20States%20and%20Europe&utm_medium=email&utm_content=417534643&utm_source=hs_email
