METHODOLOGY FOR SELECTING ALTERNATIVE ENERGY SOURCES IN THERMAL ENERGY RENOVATION OF BUILDINGS

Modern energy systems worldwide are facing the imperative of transitioning to sustainable energy supply models that do not contribute to the accumulation of carbon in the atmosphere or exacerbate the greenhouse effect, a factor now widely recognized as a key driver of global climate change. To ensure universal access to energy resources, improve environmental quality, and meet the growing energy demands of humanity, a comprehensive transformation of all elements of energy infrastructure is required. This transition does not have a singular or simple solution and demands a multidimensional approach. Reducing greenhouse gas emissions can be achieved through the integration of various energy sources and technological solutions that ensure high levels of efficiency and economic viability. The renewable energy sources and improvements in energy efficiency play a leading role in achieving climate neutrality. The reliable methods for comprehensive implementation, ensuring sustainable heat energy supply in buildings while providing comfortable conditions during the winter season is of key importance. Energy-efficient modernization of heating systems in buildings, with an increased share of renewable energy sources for heat production, is of paramount importance for the reconstruction of Ukraine. The paper proposes an approach, based on a heating system model that evaluates the impact of each innovation through the integration of energy, environmental, and economic performance indicators. The mathematical model of the building heat consumption estimation based on energy audit, which determines the initial building condition is presented. Every possible renovation action, including the change of the heating source is evaluated, and energy, environmental, and economic performance indicators are defined, enabling to find the optimal solution based on the multi-objective optimisation. The proposed approach serves as a valuable tool for preliminary engineering calculations during the design phase. The application of this model is demonstrated through a case study of an administrative building in Kharkiv. The evaluation of building thermal modernization and the installation of a heat pump was carried out based on environmental and economic performance indicators. The implementation of the recommended modernization measures in 2020, coupled with the analysis of measurements at the actual site, revealed a discrepancy of 15% between the predicted and measured heat consumption values. This finding supports the recommendation of the proposed method for enhancing heating systems in buildings.