The research is aimed at the study of physical and technological possibilities of saving thermal energy and scientific justification of energy efficiency of creating microclimate in the solar greenhouse of trench type.

The research objective is to technologically solve the problem of reduction of power consumption of greenhouses by means of enclosing structures.  

Methodology. Based on the natural and climatological conditions, a mathematical model of thermal engineering calculations has been made, aimed at determining the effect of thermal resistance on the heat loss of enclosing structures in terms of volume and area of the cultivation structure.

Results. On the basis of the mathematical model, the physical and technological possibilities of thermal energy saving were theoretically and experimentally investigated, and the energy efficiency of the solar greenhouse microclimate of trench type was scientifically proved. The temperature regime depending on the solar radiation penetrating into the greenhouse in the regions of Turkmenistan was given. The temperature regime of the air in a greenhouse and the outside air was studied, depending on the optical properties of an enclosing structure and the temperature for design of greenhouses, selection of power of additional heating in winter, cooling in summer, for the purpose of economy of energy resources in the regions of Turkmenistan is studied. The article analyzes the issue of reducing the cost of greenhouse product, heat supply and reducing investments in the construction of boilers, which can be solved by: increasing the thermal resistance of enclosing structures while maintaining high optical properties in the biologically active region of the spectrum; reducing the breathability of enclosing structures, which will reduce the heat consumption for heating of the air infiltrated into the greenhouse; reducing the volume of cultivation facilities and reducing the area of enclosing structures; rational distribution of heat sources in the airspace of the cultivation facility; when using renewable energy sources (creation of conditions for maximum accumulation of solar energy, ground heat) in combination with industrial thermal.

Conclusion. Thermal characteristics of solar greenhouses for cultivation of various crops in the conditions of Turkmenistan were investigated. The questions of reducing the cost of greenhouse product, heating and reducing investment in the construction of additional heating and cooling equipment in order to save energy were proposed.  The obtained results will provide an opportunity to ensure the sustainable development of the regions of the country and the introduction of cultivation, the prospects of growing crops in arid regions of Turkmenistan, using renewable energy sources and thermal waste.