Modeling of structural and technical and economic indicators using the T*SOL software product

Abstract

This paper addresses the issue of domestic hot water supply in private households in the context of rising prices for conventional energy carriers, energy insecurity, and international commitments to reducing CO₂ emissions. As an alternative solution, the study explores the use of solar thermal systems capable of partially or fully covering hot water demand under the high solar insolation conditions of Southern Ukraine. The objective of the research is to develop an optimal configuration of a solar thermal system for a private house in the Odesa region and to provide a quantitative assessment of its efficiency based on dynamic modeling in the T*SOL environment. The study presents a detailed methodology for estimating the thermal energy demand required to heat the daily water volume, taking into account the number of residents, temperature parameters, and water consumption standards. The required collector area is calculated with consideration of average daily insolation, tilt angle, equipment efficiency, and seasonal fluctuations. The approach to determining the number of collectors and evaluating the actual thermal output of the system during the summer period, when insolation reaches its peak values, is also described. Modeling results show that the annual solar radiation received by the collectors amounts to 12,899.82 kWh, of which 4,935.53 kWh is converted into useful thermal energy. The system is capable of covering more than 90% of hot water demand in summer months, significantly reducing gas and electricity consumption. However, several limitations have been identified: heat losses in the storage tank and pipelines (≈13% of annual output), limited storage capacity, dependency on weather conditions, and reduced efficiency during winter. Potential ways to improve system performance include enhanced thermal insulation, optimization of pump control strategies, expansion of collector area, transition to vacuum tube systems, and improvement of stratification within the storage tank. The advantages and drawbacks of using propylene glycol as a heat transfer fluid are considered. Additionally, the importance of economic assessment and the feasibility of implementing monitoring systems are emphasized to ensure reliability and operational efficiency. In conclusion, the study confirms the high potential of solar thermal systems for household applications in Southern Ukraine, highlights their strengths, and identifies technical optimization strategies to achieve greater energy autonomy