A specific feature of the market for the transport of perishable goods is the length of the routes. As part of the implementation of new technical solutions for isothermal rolling stock, research is being conducted on the development of autonomous power supply complexes. The article discusses combined power supply system of an autonomous refrigerated car (ARC), which includes a diesel generator set and a carriage generator. Possibility of using liquefied natural gas as a motor fuel for a diesel generator set, as well as generator and drive units with a car generator is being evaluated. Taking into account the operating experience of power plants of cars in the mode of unmanned technologies, the advantages of using liquefied gas as fuel are described. Comparative calculation of the costs of various types of fuel by the ARC power plant is given. The advantages of using the utilization of the heat of vaporization of liquefied natural gas (LNG) to increase the cooling capacity of a regular refrigeration unit are substantiated. Article gives comparative calculated economic assessment of fuel costs when using different options for power supply systems on routes when driving at high speed and accelerated refrigerated trains, which allows determining the required onboard fuel supply for different options. The use of LNG as a motor fuel and an additional source of cold for ARC is promising. Autonomy of the car on existing fuel reserves is increased by reducing the operating time of refrigeration and power plants. Reducing operating costs is achieved through savings on the purchase of fuel, since the price of an equivalent amount of LNG is lower than that of gasoline or diesel fuel. Operational advantages of LNG are to protect the fuel system from corrosion and contamination. The use of a generator-drive unit with a car generator will save from 30 to 70 % of the fuel used (LNG or diesel), depending on the speed of the freight train on routes of considerable length.