Research of the Energy Efficient System of a Solar Greenhouse with Solar Energy Storage

Abstract

The paper presents the results of experiments with a solar greenhouse used to ensure the most favorable temperature regime. In order to provide thermal insulation and reduce heat losses, a solar greenhouse structure with an arched shape and a total area of 200 m² has been developed. It is located directly in the ground, at a depth of 0.5 m and a height of 4.0 m above ground. The total height of the greenhouse is 4.5 m, the length is 20 m, and the width is 10 m. These dimensions comply with the standards established in KMK 2.09.08-97 Greenhouses and Hotbeds. On the outer part of the solar greenhouse, a layer of dry straw with sufficient permeability to sunlight is placed between two transparent enclosures during the winter period for thermal insulation. This significantly reduces heat losses through the top transparent surface and enhances the greenhouse effect. This transparent enclosure design allows heavy mechanical loads, is resistant to mechanical cleaning processes, and at the same time, has high thermal insulation properties. By using the solar greenhouse structure with the energy flow scheme presented, a more homogeneous air environment with temperature inside the greenhouse can be achieved, even during daily fluctuations in the temperature of the surrounding air. The temperature and humidity parameters inside the solar greenhouse vary due to the absorption of solar radiation from the ground surface and the evaporation of moisture from the soil. The results of the experiments show that the solar greenhouse based on our energy flow scheme, using the ground as thermal insulation, significantly reduces heat losses through the floor. The method of insulation between two transparent enclosures provides a more homogeneous air environment with air temperature inside the greenhouse, despite significant daily fluctuations in the temperature of the surrounding air, and effective accumulation of solar energy inside the solar greenhouse.