Modelling is carried out of the coverage of electric energy consumption for an electrical power node, which includes consumers with the maximum possible consumption power during one hour at the level of 4 MW, distributed generation power plants, namely wind, solar, reserve gas power plant and energy storage system. The costs necessary for the implementation and further operation of distributed generation power plants and energy storage systems were formed, and the income level was determined for the case of synchronous and isolated mode of operation of the studied electrical power node with the power system. In the study, it is assumed that in the synchronous mode, producers of electric energy carry out sales, and for consumers, suppliers carry out the purchase of electric energy on the “day-ahead” market, the operator of the energy storage system as a separate market participant provides auxiliary services for regulating the frequency and active power in the power system. In the isolated mode of operation, the consumption of an electrical power node is fully satisfied by its generating capacities, while the cost of electric energy for consumers is determined based on the total cost of electricity production and storage. According to the results of calculations, it was determined that when a switch from synchronous to isolated operation of a power node with the power system, the discounted payback period of distributed generation power plants with energy storage system increases from 5.5 to 8.7 years.