Assessing the effectiveness of using vacuum solar collectors in a hot water supply system in the climatic conditions of Turkmenistan

This scientific article is devoted to the study of the efficiency of using vacuum solar collectors with a useful area of 1.6 m2, installed on the roof of an experimental two-story residential building in the climatic conditions of Turkmenistan. It was revealed that in January, the incoming total intensity of solar radiation falling on the receiver (collector) located at an optimal angle of 360 is equal to 227.66 kW∙h, and it was determined that 136.6 kW∙h of thermal energy is generated, with an efficiency of 60%. In August, with a total intensity of solar radiation of 312.98 kW∙h falling on 1.6 m2 of the collector surface, 187.79 kW∙h of thermal energy is generated with the same η=60%. The conducted research by the Lui-Jordan method showed that the installation of one solar collector with an area of 1.6 m2 from January to December covers the consumption of thermal energy by 85%, 90%, 101%, 107%, 125%, 154%, 156%, 152%, 122%, 103%, 90% respectively. It was revealed that such a discrepancy follows from the fact that in summer the consumption of hot water is less, and in winter it is more. Unfortunately, the production of thermal energy is the opposite. A proposal has been developed to use a backup in the form of a boiler to compensate for the lack of energy in winter, taking into account the low cost of fuel in Turkmenistan.