Dynamic analysis of the similarity of objects in research on the use of renewable energy resources in European Union countries

The energy transformation towards renewable energy sources in the conditions of climate change and the accompanying climate risk is a priority for all countries in the world. However, the degree of advancement of activities in this area varies significantly between countries, which is the result of different activities for renewable energy sources in individual countries. The aim of this article is to determine the trends of changes in the area of the use of renewable energy sources in EU countries. The study uses TMD (taxonomic measure of development) methods and dynamic classification, which allowed to distinguish typological groups of objects with similar dynamics of the studied phenomenon. The EU 28 countries were analyzed. Statistics (Eurostat database) are provided for the period 2004–2019. As a result of the research, it was found that the Scandinavian countries and the countries of Western Europe were characterized by the highest stability in terms of the use of renewable energy sources over time. These countries also recorded the smallest increases in TMD. On the other hand, the unfavorable situation in terms of stability was observed mainly in the countries of Southern Europe.