This article considers various aspects of the functioning of electric power systems (EPSs) with a high proportion of available renewable energy sources (RES). In the absence of suf-ficient sources of basic generation in the EPS, new ways to eliminate possible consumer load jumps in the form of power reserves will be required. Based on the studies carried out in the energy systems of the Baltic States, it follows that the best way to ensure stable and safe operation of power plants in these conditions is to use energy storage devices in the form of a battery energy storage system (BESS). The BESS battery system will be able to provide reserves more economically than most power plants that use organic fuels. A model for the distribution of production capabilities of an electric power producer with specified energy characteristics in market conditions is proposed. The practical imple-mentation of the model makes it possible to obtain the initial data for creating characteris-tics of price proposals in the formation of a market for power reserves. The implementa-tion of the model is illustrated for a concrete example.