This article is devoted to the methods for increasing the operational efficiency of the singlestage and two-stage schemes of heat pump installations for heating systems, based on the energy saving principles. The major aim of the study is the analysis of methods for increasing the efficiency of alternative low-potential heat pump installations based on the subsoil waters, which correspond to the requirements of the energy saving technologies. To achieve the aim a comparative analysis of efficiency of different schemes of heat pump heating systems was performed for the consumers of the South-East of Europe. The rational schematic and constructive solutions and the system operational modes that ensure the increase in the efficiency of the alternative heating system for various climatic conditions were grounded. The main ways of increasing the efficiency of the low-potential heating systems using the heat pump units based on the subsoil waters were determined. Recommendations for the practical application of the alternative heating system solutions, depending on temperature of the outside air were developed. The significance of the obtained results consists in justification of conditions, which make it possible to use the single- and two-stage HPI schemes on the subsoil waters in the South-Eastern Europe. The most significant results are those recommending the increase in the operational efficiency of the heat pump systems on the subsoil waters for the heat supply for the consumers of the South-Eastern Europe. The analysis results can be used for designing the heating systems based on the heat pumps using the low-potential energy of the subsoil waters.