Greenhouse cooling demonstration with renewable energy-based tri-generation system

Achieving carbon-neutral greenhouse operation while avoiding peak electricity demand remains challenging because of the high cooling load and the lack of field-scale experimental validation. This study proposes an operational strategy to maximize cooling performance in a heating-oriented greenhouse thermal management system (GTMS) without equipment expansion. A fuel cell and renewable energy-based tri-generation system integrating power generation, waste heat, and solar thermal energy was implemented in a 660 m 2 smart greenhouse. Fuel cell electricity drives heat pumps, while recovered waste heat and solar energy are upgraded via a designed heat pump to operate an adsorption chiller. Under the baseline operation, the system removed up to 80 kW and maintained the greenhouse 7–8 °C below a ventilation-only reference, providing field data that have been lacking for this configuration, but a single cold thermal storage tank caused temperature mixing and repeatedly stopped the adsorption chiller through excessive temperature decrease. A temperature leveling strategy using dual thermal storage tanks then reduced this interruption from 6 h to 20 min, lowered supply water temperature from 15.15 °C to 13.95 °C, and increased daily heat removal from 1259 kWh to 1362 kWh. These results demonstrate that a field-based operational strategy can enhance GTMS efficiency.