Abstract-This article is devoted to the development of technical solutions and structures aimed at improving energy efficiency of solar plants in the regions with temperate continental climate through the adaptive control of coolant velocity. The main development stages of the adaptive control system and its operating features are considered in the article. To determine the optimal settings of the coolant loop controllers and the hot water loop, mathematical identification of the solar plant was made. Basing on different values of external factors (ambient temperature, insolation) and coolant velocity, static characteristics of the solar plant of extreme nature were obtained. The transient response analysis was used to obtain the dynamic solar model. On the basis of the developed models an adaptive step-by-step algorithm for controlling heat exchange process was created. Data on the state of the plant received from the sensors were also used. An adaptive automatic control system for solar plant of hot water supply was developed. Its application makes it possible to increase energy efficiency of hot water supply due to the increase in the amount of accumulated thermal energy at low control costs. Indirect compensation of external influences would be a distinctive feature of the method, which allows improving the quality of control processes.