Alternative energy currently has all the technical means that allow it to be considered a classic addition to traditional methods of energy production. Modern energy technologies require a more effective and reliable solution to the problem of energy supply based on the integrated use of various types of renewable energy sources, energy accumulators of various types, heat pumps, combined means of thermal modernization of buildings and alternative fuel energy backups. In modern heat supply systems using alternative energy sources, usually at least 2 heat sources are used - a renewable heat source and a traditional source as reserve and peak. The operation of gas, solid fuel, pellet and electric boilers, solar collectors, various types of heat pumps in the heat supply systems of buildings and civilian buildings is analyzed. The high-quality operation of the heat supply system is affected by various schemes of connecting consumers to heat generators. The specifics of the effective operation of the combined heat supply system are the coordination of various hydraulic “generator-consumer” modes. In practice, three approaches are used to coordinate the modes of operation of alternative heat supply systems with consumers: regulation of the power of the heat source, programming of heat consumption modes, introduction of heat accumulators. It is important to find out the conditions for the effective use of heat accumulators for intermittent heating mode, which can ensure a decrease in the thermal power of a heat generator operating in superheat mode. The operation of the pilot plant of the integrated system of alternative heat supply (ISAHS) was studied, the technical and economic indicators obtained for the heating period for three different types of heat generators: gas boiler, pellet boiler, heat pump were analyzed. An experimental study of the combined heat supply system for various heat supply facilities made it possible to establish that for public buildings, a rational way to increase their efficiency is the use of intermittent heating modes, a two-stage storage system, and coordination of structural and mode parameters of the main contours of the system. Keywords: combined heat supply system, boiler, solar collector, heat pump, heat accumulator