The result of the implementation of technical solutions should be evaluated in terms of the effect on the power system as a whole. At the same time, the main task is to obtain a socio-economic effect noticeable for the consumer of energy resources, as he is a key figure of the energy system. The article considers the influence of modernization of hot water supply systems (HWS) by transferring the function of hot water preparation in apartment buildings to individual heating stations (IHS) from the district heating stations (DHS) with their subsequent liquidation, as well as the elimination of hot water supply grid. The expected result of these measures is the reduction in heat energy loss in heat carrier agents in heating networks, as well as improving the quality and reliability of the hot water supply system and the possible reduction of energy consumption by residents in apartment buildings. The effect on the operation of the heat supply system will not be provided by IHSs themselves, but by automatic controllers, installed together with them. This, in turn, will make it possible for the Central Heating and Power plants (boiler) to be modernized in operation in a timely manner, to improve the system's efficiency. Computational studies were carried out in order to assess the impact of the transition from IHS to hot water supply on the energy system. The impact of the modernization of the hot water supply system by installing individual heating stations in the energy system of KazanKazan JSC Tatenergo implemented the program of transition to IHS in its heat supply grids, which stipulated the installation of 1,353 IHS modules in