Optimizing Rooftop PMFC Systems for Clean Urban Energy

In the face of accelerating global climate change and ecological degradation, the demand for renewable, decentralized, and low-impact energy solutions has never been more urgent. Plant Microbial Fuel Cell (PMFC) systems have emerged as a promising technology for sustainable electricity generation. While PMFCs have demonstrated viability in controlled environments, their long-term performance under variable climatic conditions remains underexplored. This study investigates the feasibility and performance of PMFCs deployed on rooftops in a temperate urban climate, where seasonal fluctuations in temperature and moisture present significant operational challenges. Our findings reveal that while electricity generation is feasible, performance significantly declines during periods of drought and when ambient temperatures drop below 5°C. The highest bioelectric output reached a power density of 28.2 mW m–2 and a current density of 123.81 mA m–2. We propose several strategies to enhance the functionality of bioelectrochemical systems in urban roofs. These include the integration of PMFCs into intensive green roof designs, the utilization of building-derived waste heat, the application of nutrient fertilizers, and the selection of drought-tolerant plant species with high biomass productivity and robust rhizodeposition potential. This study demonstrates the potential of rooftop PMFC systems as a base for green roofs, providing both ecological benefits and opportunities for renewable energy generation. The findings contribute to the advancement of resilient, nature-based bioenergy infrastructure for sustainable urban development.