Fuel cell based tri-generation system for horticulture – part 1. Heating

This study presents the development and experimental validation of a hybrid tri-generation system that integrates proton exchange membrane fuel cells, a solar heater, and electric heat pumps for greenhouse energy applications. The system was implemented in a pilot-scale greenhouse and achieved a modeled-to-measured heat load deviation of less than 2.27 %. Two operational strategies were evaluated under both normal and extreme cold conditions: a heat load-adaptive strategy that ensured thermal stability, and an optimized strategy that prioritized electric heat pumps operation during periods of high efficiency. The optimized strategy resulted in operating cost reductions of 9.1 % and 5.7 % under normal and extreme cold scenarios, respectively. Sensitivity analysis identified fuel cells efficiency and electric heat pumps performance as the most influential parameters affecting system economics. Compared to conventional tri-generation systems relying solely on fuel cells, the proposed hybrid configuration offers enhanced seasonal adaptability, improved renewable energy utilization, and reduced dependency on the electrical grid. These findings demonstrate the viability of a scalable, low-emission energy solution for controlled agricultural environments. Limitations regarding capital investment estimation, cooling performance in summer, and long-term component degradation are acknowledged and will be addressed in future research.