A new study published in Scientific Reports reveals an approach to improving greenhouse sustainability and effectiveness in the Sahel region. Conducted by Alio Sanda M. Djibrilla, Adamou Rabani, Karimoun M. Illyassou, Atto H. Abdoulkader, and Drame Yaye Aissetou, the research focuses on the thermal behavior of photovoltaic evaporative cooling greenhouses equipped with eco-friendly coolers.
The study addresses the impact of anthropogenic climate change, which has exacerbated extreme weather events such as droughts, floods, and heatwaves, particularly affecting food security in developing countries. The innovative greenhouse design is critical for ensuring food, energy, and water security in regions like the Sahel.
Researchers assessed the cooling potential of local plant materials under ambient conditions, using experimental thermal data from an optimized evaporative cooling system featuring Hyphaene thebaica fibers (HF-pad) and the conventional Celdek pad (C-pad). Heat and mass transfer equations were applied to determine greenhouse cooling performance, and computational fluid dynamics analysis was utilized to evaluate refrigerant fluid distribution.
Results showed that the HF-pad cooler maintained the greenhouse microclimate below 25 °C with a maximum moisture rate of up to 80%, even under harsh conditions (ambient temperatures of 30–45 °C and humidity levels of 10–15%). The HF-pad demonstrated superior cooling performance, with a coefficient of performance (COP) of 9 compared to 6 for the C-pad, and the best cost-to-efficiency ratio (CER) of 5, which is four times less than that of the C-pad. The HF-pad also achieved the lowest outlet temperature at 20.0 °C.
While the C-pad cooler spread cool air (20.5 °C) farther than the HF-pad, creating higher atmospheric pressure and greater turbulent kinetic energy, the HF-pad's overall cooling performance was competitive. Moreover, optimization of the HF-pad frame engineering and scaling the technology to an industrial level could enhance both thermal and economic efficiency.