In the United Energy System (UES) of Ukraine retained the negative trend of significant irregularity of daily electricity consumption schedule, especially in autumn and winter period. UES Ukraine daily load schedule irregularity in 2016 amounted from the 4500 MW in summer up to 6500 MW in the winter period. This situation requires finding effectiveness evaluation methods of management decisions in the energy sector implementation, particularly at power consumption management. One available power consumption managing option is tariff system, differentiated by time of use periods, which effectiveness is ensured by usage of consumers potential in power consumption reduction. An important step in research of such consumers opportunities is to determine its response to proposed changes in the tariff system. This approach significantly reduces the risk of management methods implementation. Allows to make adjustments at initial stages. Basic for such assessment implementation are communication methods. A further step is processing of expert surveys results and usage of fuzzy logic elements. Article reviewed methodical approaches for defining existing differentiated tariffs improving priorities. Conducted research of dependence between or tariffs coefficients level established for allocate day zones and consumers electrical power demand changes that occurred or could occur through the use of differentiated tariffs in terms of their multivariate characteristics. Expert data and fuzzy logic methods usage allows to recive fuzzy inference models, that are used in analysis of differentiated tariffs impact at energy system by changing the price rates. Obtained dependencies allow to change electricity consumption and receive predicted values with a given probability.