The goal of the article lies in the study of the modern state of power engineering companies of Ukraine, on the basis of the clarification and systematization of the existing in scientific literature approaches to the classification of the energy saving potential. Effective state development is impossible without a balanced and minimal consumption of energy resources. This is due to the exhaustion of non-renewable natural resources, the risks associated with their transportation, the lack of real alternatives to their replacement. The present state of Ukraine's energy security is investigated and its problems are determined. The interconnection of the economic state of the environment with the introduction of energy-efficient technologies of equipment, equipment, household energy devices is determined. The feasibility of using renewable energy sources and alternative fuels is established. The problems of ecology and their interrelation with the development of the state economy are characterized. The analysis of dynamics of energy consumption by enterprises of mechanical engineering for 2011 - 2017 years. The main mechanisms of state regulation of energy efficiency of mechanical engineering enterprises are separated. The State Target Economic Program for Energy Efficiency is described and characterized. Proposals on energy efficiency improvement of engineering enterprises are presented. Conclusions. An energy analysis of the studied machine-building enterprises, carried out, revealed the presence of significant energy losses and allowed to draw a conclusion on necessity of application of energy efficiency measures that will further reduce energy costs.