This article reviews the distributed generation facilities techno-economic efficiency evaluation conducted in the existing or projected power supply systems. It suggests the calculation algorithm, adapted to KATRAN-OptActivePower software. It accounts for the technical-economic models of generators, the configuration and the equipment parameters to evaluate the main performance indicators: network power losses costs, total expenses (including the maintenance and repair costs, and the volume of capital investment in equipment). To evaluate the energy sources implementation efficiency the network generation and transmission costs, before the additional sources are installed, are compared to those after the installation. The payback period is set as 8 years. The calculations also account for the generators’ technological features. The article presents an exemplary case of efficiency evaluation for the generators installed in the active power supply grid.