Improving energy efficiency is key to moving toward sustainable development. It contributes to the reduction of energy consumption and carbon emissions, as well as to climate change mitigation. Indicators of energy efficiency play an important role in this field because their improvement is targeted by policy makers. Indicators based on the ratio between energy consumption and gross domestic product (GDP) are currently used by multiple key organizations, including Eurostat and the World Bank, as the main energy efficiency indicators. This study examines the most widely used indicators and identifies their deficiencies. Over the last decades, these indicators tend to show a continuous strong improvement, signifying positive progress toward energy efficiency, even in cases when the physical consumption of energy has increased significantly. This phenomenon is based on GDP adjustment. The energy intensity of economies, used currently to measure energy efficiency, masks problems and has led to the green labeling of wealthier economies. An analysis of energy efficiencies reported for multiple countries and the structure of their energy spending shows that the reported values are counterproductive for comparing economies in the context of environmental protection. The indicators sanction economies with low energy consumption and low or moderate GDP. The economies belonging to the group of the largest energy spenders per capita are labeled highly efficient because of GDP adjustment. Decision makers are therefore prompted to focus on GDP growth even at the cost of a major increase in energy consumption. An additional problem in the indicators is that they do not properly model international trade. The responsibility for energy spending is shifted toward the producers of energy-intensive goods and services. Energy intensity is a useful indicator to measure the resistance of an economy to the volatilities of energy prices. However, the challenges in the fields of environmental pollution and climate change are related to physical processes and energy consumption rather than to changes in the GDP or the monetary valuation of products and services. Indicators measuring energy efficiency as GDP per unit of energy use are inadequate and misleading as principal tools to measure energy efficiency.

In this paper, selected aspects of energy efficiency are shown. The European Union regulations in area of energy efficiency such as Directive 2012/27/EU, are discussed. The national legal regulations which describe energy efficiency such as the Energy Efficiency Act are presented. Principles concerning the obligation of energy savings and energy audits of enterprises are described. National, regional and local programs and measures concerning the improvement of energy efficiency are performed. These are horizontal measures and energy efficiency measures in: industry, transport, the buildings of public institutions and energy generation and supplies. National economy energy efficiency is shown. The energy intensity indicators (primary, final) and rate of their changes in last years are performed. Moreover, directions of undertakings connected with the possible future reduction in energy intensity of the national economy, are defined. An analysis of energy efficiency measures and solutions for the improvement of energy efficiency, especially in industry and households, is performed. The improvement of economy energy intensity indicators constitutes the most effective solution which brings significant economic, technical and environmental benefits such as an increase in economic innovation and its competitiveness, the improvement of the energy supply security level, a reduction in the consumption of natural resources and a reduction of air pollution and greenhouse gas emissions. The conclusions contain an analysis of the present level of energy efficiency in Poland and the perspectives of its increase in the future along with the benefits connected with it.

The world economy is constantly faced with crises that cause a significant negative impact. Each crisis poses new challenges to the economy and, on the one hand, inhibits economic growth, and on the other hand, can become a powerful stimulus for the development and rethinking of fundamental approaches to its construction. Conducting an analysis and establishing relationships between the economic situation and the state of the energy sector make it possible not only to predict the future but also to develop specific steps to prevent crises or reduce their negative impact. At the same time, establishing and evaluating the relationship between key economic and energy indicators, the main one of which is definitely the energy intensity of GDP, will provide an opportunity to understand how improving energy security will affect the economic situation in the country. The generalization of Ukraine’s experience in rebuilding and recovering the economy after the biggest crisis creates a basis for further research in the field of energy management, crisis management, economics, and the construction of investment policy. The reconstruction of Ukraine after the war has the potential to become the most significant stimulus for development and economic growth. During the crisis, it is very important to pay attention to the country’s energy security. In particular, it is necessary to ensure the diversification of energy resources, taking into account their rising cost. Energy markets are currently experiencing extreme volatility caused by geopolitical tensions, which requires additional attention in the development and implementation of strategic guidelines for sustainable economic recovery in Ukraine.

The purpose of this research work is to study the issues of the protection of 6–10 kV lines and access ways overvoltage in the electrical networks of modern enterprises of high-energy intensity, as well as the search for real technical opportunities to improve the protection of power lines directly in conditions of their operation. The methodology of this scientific research is based on a combination of methods of system analysis of the principles of the functioning of electric networks of energy-intensive enterprises with an analytical study of the fundamental aspects of ensuring the protection of 6 to 10 kV lines and access ways from overvoltage. The results of the conducted scientific research indicate the relevance of the issues of ensuring the protection of lines and electrical networks of energy-intensive enterprises from overvoltage and the need to develop special technical devices to ensure the proper level of such protection in real conditions. The results and conclusions of this research work are of significant importance for developers and designers of electric networks of enterprises with increased energy capacity, as well as for employees of various power supply systems who, by their occupation, face the tasks of servicing electric networks, which include lines and access ways with specified operating voltage parameters and ensuring the proper level of safety and practical use of these electric networks of energy-intensive enterprises.

The role of energy as a key factor in enhancing sustainable development, energy security, and economic competitiveness is a reason that has made energy efficiency trends tracking essential and is why policymakers and energy planners have focused on energy intensity and its following issues. Also, the inadequate operation of the traditional energy intensity index and the overestimation of its results turned this index into a weak one. Hence, it is necessary to employ a new index that can be decomposed and is capable of considering both monetary and physical activity indicators to offer a more accurate view of the energy intensity variation. This paper develops a Composite Energy Intensity Index by combining monetary and physical activity indicators by applying the multiplicative Logarithmic Mean Divisia Index (LMDI) in 2001–2011 to decompose the factors affecting energy intensity change and seeks to fill the gap between the EGR and CEI indices. The results of the survey demonstrate more economy-wide energy consumption reduction while using the composite energy intensity index as compared to the traditional energy intensity index; also, the results show the relatively important role of the overall structure effect. From Sectoral perspective results, both energy to GDP index (EGR) and composite energy intensity index (CEI) have shown passenger transport as the most energy-consuming sector. The passenger transport sector reveals an urgent need for implementing appropriate policies to reduce the high energy consumption of the sector.