Abstract
Saving energy and looking for alternative energy sources are both elements of energy efficiency management, which is still a significant challenge for many companies around the world. Unfortunately, energy efficiency in companies is often equated only with thermo-modernization or the replacement of lighting. However, one of the most important methods of improving energy use in manufacturing companies may be the modernization of the machine park. Therefore, the main purpose of the paper was to investigate the activities of enterprises in the field of the modernization of machines and the impact of this on the actual improvement of energy efficiency. The modernization of machines in production plants is understood as adapting new parts to the old device or rebuilding the machine in such a way that it can cooperate with its new subassemblies. Companies usually decide to modernize the machinery fleet, bearing in mind the benefits of production efficiency, and they do not always combine this modernization with energy efficiency improvement measures. This is confirmed by the presented results of a survey conducted with a group of 111 manufacturing companies. Several important statistical relationships in the studied area were indicated by conducting an analysis based on the chi-square test and, in some cases, by clarifying the results of the z-test with the Bonferroni correction.