Accumulators of high thermal capacity are organized in a natural soil mass ordered by a set ("bush") of vertical/horizontal heat exchangers, which are placed either in boreholes or inside cylindrical cavities of a concrete mass in pipes. As a result of accumulation, a main region of accumulated heat is created, which is limited by the outer contour of the "bush", of a certain volume and with a certain temperature, as well as a buffer sub-region of a certain volume, which touches the main one and is the result of thermal interaction of the volume of the main region with the surrounding soil mass, which has constant temperature. The smallest dimensions of the buffer subregion will be in the case of a uniform temperature distribution over the main volume. This is achieved by organizing the same heat load that falls on each heat exchanger, the same potential of the intermediate heat carrier and a small difference in its temperatures, respectively, at the inlet and outlet of each heat exchanger, and a number of other requirements. The dimensions of the buffer subregion can be reduced by creating an upper heat shield. This will lead to a reduction in the dimensions of the entire structure and there will be no need for thermal insulation of pipelines that supply and discharge the coolant in the middle of the heat accumulator. In this case, the dimensions of the structure must be optimal, i.e. meet a certain criterion, in which the ratio of the volume of the buffer subregion to the volume of the entire heat accumulator is minimal. An improved method of structural-parametric optimization of ground heat accumulators in the process of analyzing their functioning is presented. The optimal ratios of the dimensions of these accumulators with an upper heat-insulating shield (or without it) and a developed technique are determined that allow finding the number of heat exchangers, their parameter and the distance between them to ensure minimal costs for building an accumulator.