The increase in energy demand requires urgent investments in sustainable energy. It is vital to the success of the 2030 Agenda, adopted by the United Nations General Assembly. The article aimed to assess the situation of the European Union countries with regard to energy use. Indicators related to the implementation of SDG7 and environmental and resource productivity of the economy were adopted for the study. The research presented in this article fits into contemporary debates on the effectiveness of implementing one of the SDG7: ensuring access to affordable, reliable, sustainable, and modern energy for all. The analysis included 26 countries that have been in the European Union since 2010. The study’s originality lies in the use of primary data obtained from the Eurostat database for three research periods: 2010, 2015, and 2020, which will allow for assessing the situation of the surveyed EU countries in the area of energy use. In order to achieve the research objective, selected methods of descriptive statistics and vector measurement were used. The application of a vector measure made it possible to rank the studied countries in terms of efficient energy use. Based on the results obtained, there is a significant variation in space and time in the evolution of the energy system of the European Union’s member states toward sustainable development. Rational energy use is primarily the domain of north-western European countries, with Sweden and Austria always leading the rankings. However, this does not mean that in these countries, in spite of their high position in the ranking, the levels of some indicators in 2015 and 2020 as compared with those in 2010 did not deteriorate. Due to this fact, attention should be paid to the energy use process and identification of signals responsible for deteriorating the outcomes. The research results can help diagnose the results obtained so far and correct the European Union’s climate and energy policy in the future.