The article describes the approach to the selection of parameters of a hybrid electrical energy storage system (EESS) based on supercapacitors (SC) and lithium ion battery (LIB) for an autonomous power station with a diesel generator set (DGS). The calculations of transients in an autonomous power supply system with an abruptly variable load and participation of a hybrid EESS. The procedure of determining the share of participation in the energy exchange of storage subsystems based on LIB and SC is presented.