A Comparative Analysis of Heat Supplying Models with Seasonal Heat Storage for a Greenhouse

This study aimed to investigate the feasibility of employing solar energy for seasonal thermal storage and utilization in horticulture facilities. The implementation of geothermal heat pump systems in large-scale horticulture farms has encountered challenges due to the substantial investment costs and operational stability concerns related to heat source temperatures. To address these limitations, this study proposes the novel concept of seasonal thermal storage and utilization. By incorporating a suitably sized storage tank, the capacity requirements of costly energy generation facilities like heat pumps can be significantly reduced, ensuring more consistent annual operation. Nevertheless, the installation of solar collectors for seasonal thermal storage may present additional challenges due to lack of space to accommodate large collectors, particularly in urban areas where the cost of land is high. This study considered two variations of seasonal thermal storage and utilization models, and conducted a comprehensive analysis of their operational characteristics and energy utilization. Through simulations and comparative analyses using an in-house developed simulation tool, the optimal design variables are determined, and the detailed operational characteristics are evaluated. The findings of this study furnish technical evidence supporting the viability of seasonal thermal storage and utilization, offering substantial benefits that can be applied in horticulture facilities.