Results of numerical modeling of the efficiency of a hybrid municipalheating system for the climatic conditions of Southern Ukraine

Abstract

The current development of Ukraine’s energy sector is defined by the growing demand for thermal energy and the urgent need to reduce the use of fossil fuels, which highlights the importance of energy efficiency and the integration of renewable sources into heating systems. Particular attention is drawn to hybrid solutions that combine heat pumps with ground heat exchangers and solar collectors, enabling a balance between reliability, cost-effectiveness, and environmental sustainability. The aim of this study is to substantiate the feasibility of applying a hybrid heating system for an administrative building in Odesa, where the combination of high solar radiation and specific climatic conditions creates unique opportunities for the efficient operation of such systems. The methodological framework included analytical calculations, modeling of the heat pump cycle, numerical simulation of solar thermal systems using EKO-power software, and a techno-economic assessment of design options. The evaluation confirmed the significant impact of thermal modernization measures: insulating façades and roofs, as well as replacing windows, reduced the building’s heat losses more than threefold, creating favorable conditions for stable heat pump operation. The installation of heat recovery units in the ventilation system provided annual energy savings of over 42,000 kWh, decreasing the heating load nearly fivefold. Calculations of the heat pump cycle with a ground heat exchanger demonstrated its ability to reliably cover the base heating demand with a high coefficient of performance. Modeling of solar collectors confirmed their efficiency in summer and during transitional seasons; however, the high equipment cost results in a long payback period (over 13 years), making them more suitable as auxiliary rather than primary heat sources. The techno-economic analysis revealed that the use of a ground-source heat pump ensures the shortest payback period – approximately 2.3 years–due to low operating costs and substantial natural gas savings. The findings suggest that the optimal solution is a combined system with the heat pump as the primary source and solar collectors as a supplementary element. It is concluded that the implementation of hybrid heating systems, combined with thermal modernization and ventilation heat recovery, significantly enhances energy efficiency, reduces operating costs, and contributes to environmental sustainability. The proposed strategy can be scaled to both residential and administrative sectors of Ukraine.