Smart energy supply for smart farms: A hybrid ground source heat pump in seasonal greenhouses for growing cherries

Growing off-season cherries in seasonal greenhouses is beneficial for increasing the income of growers. The traditional compressed air conditioners commonly used in seasonal greenhouses have the problem of high operating costs. Therefore, in this paper, the TRNSYS simulation software was used to evaluate the operation of a hybrid ground source heat pump system (HGSHP) composed of ground source heat pumps, photovoltaic thermal panels (PV/T), and cooling towers (CT) in seasonal greenhouses. The system features a cooling tower with a heat dissipation capacity of 70.4 kW and PV/T components covering an area of 40 m². The operational performance and feasibility of this system in the Shandong region were investigated. The results show that compared to a system using only a ground-source heat pump (GSHP), after five years of operation, the soil temperature increased by 6.3 °C for the GSHP, while the HGSHP system resulted in an increase of 0.2 °C. The addition of the cooling tower reduced the number of vertical ground-source heat exchangers from 30 to 22, resulting in a reduction of 46,959 CNY in energy consumption over five years of operation. Compared to GSHP systems, the HGSHP system has an additional payback period of approximately 6.0 years, yielding equivalent annual cost savings of 5981 CNY and reducing carbon dioxide emissions by 13.1 tons. These findings highlight the HGSHP system's potential for providing efficient heating and cooling in seasonal greenhouses, along with its value in terms of high economic viability and long-term sustainability.