Europe’s Energy Efficiency Hits 70%, but Nearly a Third of Its Energy Supply Is Still Lost

Europe is becoming more efficient at converting energy into final consumption while steadily reducing the carbon emissions associated with its energy systems. However, beneath this progress lies a persistent challenge: nearly 30% of the European Union's energy supply does not reach final consumers, and significant differences between member states continue to shape the continent's transition toward climate neutrality.

A new study titled "Energy Conversion Efficiency and Carbon Intensity of EU Energy Systems," published in the journal Energies, examines the relationship between energy efficiency, conversion losses and carbon emissions across all 27 European Union countries. Conducted by Melinda Oroszlányová and Özgen Yalçın of the American University of the Middle East, the research analyzes energy statistics covering 1990 to 2024.

The findings reveal that EU energy conversion efficiency reached 70.19% in 2024, compared with a historical average of 64.22%. Energy losses declined to 29.81%, while carbon intensity fell to 1.7098 million tonnes of carbon dioxide per million tonnes of oil equivalent. More importantly, the research identifies a strong statistical relationship between improving efficiency and declining carbon intensity, although national performance remains uneven.

Europe's Energy Transition Reveals a Persistent Efficiency Gap

Europe's decarbonization strategy has increasingly emphasized renewable energy deployment, technological modernization and lower greenhouse gas emissions. However, the effectiveness of the energy system itself represents another critical dimension of climate performance. Producing cleaner energy addresses the carbon content of supply, while improving conversion efficiency determines how much primary energy is required to deliver energy to final consumers.

The researchers examined total energy supply, final energy consumption and conversion losses using harmonized statistics from the European Commission's Directorate-General for Energy and Eurostat. Their analysis treats energy conversion efficiency as the proportion of total energy supply represented by final energy consumption, providing a system-wide measure of energy delivery relative to primary inputs.

Across the 1990–2024 period, average annual total energy supply stood at 1,448.39 million tonnes of oil equivalent, compared with average final energy consumption of 928.93 million tonnes. The resulting average conversion efficiency was 64.22%, meaning that 35.78% of supplied energy was accounted for by conversion losses under the study's measurement framework.

The historical trajectory shows an important turning point. Energy conversion efficiency remained relatively stable until 2007 before beginning a sustained increase. Total energy supply had risen until approximately 2006, after which it generally declined. Final energy consumption followed a broadly similar pattern, although at a lower level.

By 2024, conversion efficiency had reached 70.19%, leaving an energy loss ratio of 29.81%. The improvement indicates that the EU required proportionally less primary energy to deliver final energy consumption than during much of the preceding period. Nevertheless, the remaining losses demonstrate that energy-system performance continues to represent a substantial concern alongside the transition toward cleaner sources.

Higher Energy Efficiency Is Closely Associated with Lower Carbon Intensity

One of the strongest findings concerns the relationship between energy conversion efficiency and the carbon intensity of energy use. While the two indicators measure different aspects of energy performance, their historical movements reveal a statistically significant association across the European Union.

The researchers calculated carbon intensity by comparing energy-related carbon dioxide emissions with gross inland energy consumption. Across the study period, average carbon intensity was 2.0894 million tonnes of carbon dioxide per million tonnes of oil equivalent. By 2024, this had declined to 1.7098, equivalent to approximately 40.84 grams of carbon dioxide per megajoule.

Energy-related carbon dioxide emissions remained relatively high until 2006 before following a downward trajectory. Carbon intensity also declined over the longer period, with the relationship between increasing efficiency and decreasing emissions intensity becoming particularly apparent after 2010.

Statistical testing produced a Pearson correlation coefficient of −0.7988, indicating a strong negative relationship between the two indicators. The association was highly statistically significant, while the regression model explained approximately 63.8% of the observed variation in annual EU carbon intensity.

These results indicate that years with greater energy conversion efficiency generally coincided with lower carbon intensity. However, the relationship should not be interpreted as definitive proof that efficiency improvements independently caused emissions reductions. The researchers acknowledge that renewable energy deployment, electrification, economic conditions and industrial structures may also influence the observed changes.

Improving energy conversion can strengthen overall system performance, but reducing carbon emissions also depends on the sources of energy being consumed and the broader economic activities generating demand. The findings support considering energy efficiency and decarbonization together without treating them as identical policy objectives.

Europe's Energy Divide Exposes Uneven National Progress

Although EU-wide indicators point toward substantial improvement, the research reveals striking differences among member states. National energy systems vary considerably in their conversion efficiency and carbon intensity, demonstrating that progress toward cleaner energy does not follow a uniform pathway.

Luxembourg recorded the highest average energy conversion efficiency during 1990–2024, at 92.35%, while Bulgaria registered the lowest at 50.08%. Carbon intensity showed equally substantial differences, ranging from Sweden's historical average of 0.8968 million tonnes of carbon dioxide per million tonnes of oil equivalent to Poland's 3.1746.

The researchers classified member states according to whether their long-term average conversion efficiency and carbon intensity were above or below the respective EU averages. Croatia, Latvia, Austria, Portugal and Finland emerged as countries combining relatively high efficiency with relatively low carbon intensity.

In contrast, Bulgaria, Czechia, Germany, Estonia, Malta and Poland were classified as having below-average conversion efficiency alongside above-average carbon intensity. Other countries occupied intermediate positions, demonstrating that stronger performance on one indicator does not necessarily translate into equivalent progress on the other.

Germany's inclusion among the countries facing both relative challenges illustrates why economic significance alone does not determine energy-system performance. Similarly, Sweden's particularly low carbon intensity demonstrates that strong emissions performance can coexist with conversion efficiency below the EU historical average.

National trajectories nevertheless show considerable improvement. Almost every member state achieved higher conversion efficiency in 2024 than its historical average, with Slovakia and Finland remaining close to their respective long-term levels. Every country recorded lower carbon intensity in 2024 than its historical average.

Malta registered a particularly substantial efficiency improvement, rising from an average of 54.01% to 75.22% in 2024. Estonia recorded the largest reduction in carbon intensity relative to its historical average, declining from 2.9998 to 1.8536 million tonnes of carbon dioxide per million tonnes of oil equivalent.

The findings suggest that EU-wide progress conceals different national starting points and varying patterns of improvement. They also reinforce the importance of evaluating energy efficiency and carbon intensity separately when comparing national performance or assessing energy-transition priorities.

Why Europe's Efficiency Gains Are Not the Whole Decarbonization Story

The research provides an important perspective on Europe's climate ambitions, including its objective of achieving climate neutrality by 2050 and reducing greenhouse gas emissions by at least 55% by 2030 compared with 1990 levels. According to the study, EU net greenhouse gas emissions had declined by 39.5% between 1990 and 2024, leaving further progress necessary.

The findings indicate that energy conversion efficiency deserves continued attention within this transition. Improving the relationship between primary energy supply and final consumption can support more efficient energy systems, while declining carbon intensity reflects changes in the emissions associated with energy use.

For policymakers, the national differences highlight the need to consider energy-system characteristics when designing efficiency and emissions-reduction measures. Countries experiencing comparatively high conversion losses face different performance challenges from those combining efficient energy conversion with relatively carbon-intensive energy supplies.

The study also connects energy efficiency with the EU's Industry 5.0 agenda, which emphasizes technological transformation alongside sustainability objectives. Energy-system modernization, industrial efficiency and lower-carbon energy supplies form related elements of this broader transition.

However, the researchers caution against assuming that improved technical efficiency automatically produces equivalent reductions in overall energy consumption. Changes in the scale of energy-intensive economic activities can influence realized savings, making energy demand an important consideration when assessing environmental performance.

Several methodological limitations also require attention. The statistical analysis does not account separately for renewable energy shares, national income, electrification, energy prices or industrial structure. Major disruptions, including the 2008–2009 financial crisis and the 2022 energy crisis, may also have affected historical trends.

Further research incorporating these factors could help distinguish the independent contributions of efficiency improvements and changing energy sources. The authors propose models accounting for country-specific and year-specific differences to investigate these relationships more rigorously.