The article examines the influence of the conditions for the implementation of investment projects on the level of energy consumption of industrial enterprises, as well as the amount of economic benefits received in production, and proposes an economic assessment of the efficiency of iron ore products. As an economic criterion for assessing the effectiveness of energy-saving measures, indicators were calculated that reflect the price of energy saving in relation to investment and operating costs. The practice of assessing the effectiveness of the implementation of investment projects to reduce the energy intensity of production shows that in the process of their control and operational management, priority should be given to natural indicators, and at the current stage of long-term planning – to cost indicators. An improved methodology for assessing the implementation of energy-saving technical solutions based on natural indicators is proposed. To do this, it is necessary to express the volume of production of natural units directly as a function f of the total amount of energy consumed in production (direct and embodied) and calculate the additional volume of production that can be obtained from saved energy resources during the implementation of the project, as well as the additional volume of production obtained in the basic version due to additional investments. The «given» volumes of industrial production are compared with each other. The criterion for evaluating energy saving measures using natural indicators is the minimum value of total energy costs according to the option, per unit of the given production volume. The economic assessment of energy-saving technologies is based on the calculation of changes (savings) in the following indicators: direct costs, integral costs and integral effect, calculated on the basis of indicators characterizing the amount of total energy resource savings in relation to investment and operating costs. In turn, this makes it possible to calculate the minimum volumes of energy resource savings required to ensure the effectiveness of an investment project at a given energy tariff.