Economic assessment, analysis and forecast of developing organic farming for the next ten years indicates the rapid growth of technologies for greenhouse vegetable growing in Russia. These positive trends are supported by factors such as worsening epidemiological situation in the world due to COVID-19 and transition to self-isolation of the majority of population, which requires providing healthy green products for a functional purpose. It is the need to strengthen the immune system that makes people consume vegetable products in accordance with the recommendations for rational consumption of vegetables that meet modern requirements for a healthy diet. To effectively solve the problem and in connection with the limitation of the imported products supply, the most rational solution is to modernize our domestic production of functional vegetable crops. The design of modern small-scale cultivation facilities makes it possible to ensure food security of various segments of the population living in any part of the Russian Federation. The structure autonomy and energy-saving technologies enable to operate the bio-vegetation complex all year round without being connected to an external power system. This is achieved due to the rational distribution of energy flows in the complex itself, and enables to efficiently operate it all the year round without serious additional financial costs for energy supply in the cold season. The paper presents energy-saving solutions and describes a thermophysical model of energy flows movement being an indispensable element in the design of such structures.

The efficiency of vegetable production in closed ground structures is directly dependent on the costs associated with creating artificial, controlled conditions for growing plants during the period when cultivation of them in open ground due to climatic conditions is impossible. One of the indicators of the economic efficiency of vegetable production in protected soil structures is labor costs and funds per 1 hundredweight, per 100 rubles of gross production, as well as energy costs, including thermal energy. Usually, solar, biological, electric and other types of heating are used to supply thermal energy to cultivation facilities, each of which has its own disadvantages. The bio-vegetation complexes structurally distinguished by the fact that cultivation beds are located on various foundations make it possible to create an active underground heating system. The paper presents the development of a design for an active subsurface system for thermal energy supply to the bio-vegetation complex and calculations of the main parameters of the system for autonomous operation of the object at negative outside air temperatures. The design of the active subsurface system for thermal energy supply to the bio-vegetation complex is proposed in the form of a heat-accumulating sand-gravel mass, inside of which there are heat supply circuits with a heat carrier closed with a concrete screed on top. The calculation of energy consumed by the active sub-ground thermal system providing optimal parameters of the growing medium corresponding to biological rhythms of plant development at low outside air temperatures is also presented. The study determines the area of the photovoltaic unit and the number of photovoltaic modules for generating electric energy in order to cover the spent thermal energy and the effective functioning of the active subsurface system for thermal energy supply to the bio-vegetation complex.