As European countries navigate an increasingly complex and chaotic geopolitical environment, energy security has shot up to the top of their political priorities. Across the continent, energy security is now clearly recognized as an essential public good. And the latest geopolitical upheavals, including Russia's invasion of Ukraine, the Iran War, and a more coercive and unpredictable United States, have made it clear to European leaders that they must move swiftly and forcefully to ensure that the continent's energy supplies remain secure, sustainable, and affordable.
In a new report , Brookings experts Samantha Gross and Constanze Stelzenmüller examine how a more integrated European energy system could strengthen energy security, while also furthering sustainability and affordability.
"Europe's new energy troubles provide a compelling logic for solidarity and collective action," said Stelzenmüller , the director of the Center on the United States and Europe . "The costs will be high—but the cost of inaction will be even higher."
According to Stelzenmüller and Gross , the director of the Energy Security and Climate Initiative , European energy integration holds enormous promise and could help significantly boost the continent's transition to clean energy. A more energy-connected Europe would help individual countries deal with energy disruptions and shortages. When these disruptions occur, cross-border transfers from neighboring states can ease supply and price shocks. This strategy is already being used in Ukraine and elsewhere.
Greater integration will also enable more efficient management of intermittent renewable electricity sources such as solar and wind. As more demand is met by less expensive sources from across the continent, overall energy costs will drop.
Despite this promise, the authors note that there are significant economic and political challenges to integration. Building and modernizing infrastructure such as transmission lines and pipelines will require major funding from the EU and individual member states, as well as private funding. The costs will run into the hundreds of billions of dollars, at least, and will likely lead to questions about who should pay for what. Each country will have to give up some control of its energy system, which could be politically and logistically difficult.
Moreover, while integration will almost certainly lower overall energy costs, not every consumer will be better off all the time. And some energy producers may balk at facing new competition from less expensive sources of energy elsewhere in Europe. These questions may create constituencies that oppose further integration.
Until recently, European countries focused on ensuring that they had reliable ways to import fuel as they made the transition to renewables. In 2023, the EU imported 58% of its fuel (oil, natural gas, and coal), a level that has been largely consistent over the last 20 years. But as the global energy situation has become more tenuous, the continent has increasingly turned its attention to autonomy and internal cooperation.
A key turning point was Russia's 2022 invasion of Ukraine, which led to Russia drastically reducing its exports of natural gas supply to Europe. Since Russia invaded Ukraine in 2022, the EU has worked to eliminate its reliance on Russian gas. Progress so far has been impressive: a 45% share of imports from Russia in 2021 declined to a 19% share in 2024. The EU plans to eliminate the import of all Russian gas by the end of 2027. And in December 2025, the European Commission released the European Grids Package , an ambitious plan to implement the free flow of electricity across borders. The EU is particularly focusing on expanding renewable energy production in areas that are especially suited to it, including solar energy in Spain and wind energy in the North Sea.
The EU estimates that electricity market integration already saves consumers about $40 billion a year, and that greater integration could increase this to $50 billion by 2030. Another benefit: by lowering energy costs for business, integration can boost European competitiveness.
"For Europe, these efforts can be a win-win-win," says Gross. "It will strengthen its energy security while at the same time moving more toward renewables and lowering overall energy costs in the long term."
