Feasibility, environmental, and economic analysis of alternative fuel distributed power systems for reliable off-grid energy supply

Reliable off-grid energy supply remains challenging in remote and emergency scenarios, particularly for communication base stations, where conventional single-fuel systems often face fuel dependency and supply disruptions. Building on our prior work that validated multi-fuel reforming for on-site hydrogen production, this study develops an alternative fuel-flexible power system integrating fuel reforming and fuel cell technologies. The feasibility of the system is first validated through experiments, followed by simulations to evaluate various system structures. Experimental validation demonstrates consistent hydrogen production and stable power generation from five fuels: methane, methanol, ethanol, kerosene, and diesel. Each system consistently delivers an output power near 500 W, with fuel conversions exceeding 95%, hydrogen content over 70%, and hydrogen production rates above 4500 ml/min. To optimize performance, we evaluate three system designs incorporating heat reflux and combustion heating methods evaluated through simulations. Results reveal a maximum system efficiency of 53.1%, with exergy analysis identifying significant losses in the PEMFC and reformer. Environmental analysis reveals that carbon emissions for the five fuel systems vary between 0.281 and 0.662 kg/(kW·h), with methane being the lowest. Meanwhile, the economic analysis indicates that the levelized cost of electricity for this fuel-flexible system with different fuels ranges from 0.7 to 1.1 US$/(kW·h). The results demonstrate that the system exhibits excellent economic robustness and superior cost adaptability compared to single-fuel systems, owing to its ability to adjust to varying fuel availability and cost conditions. This fuel-flexible system can address the challenges of reliable and sustainable power generation for off-grid applications, including communication base stations, remote communities, and emergency power supplies. It demonstrates high adaptability, efficiency, and economic viability, offering a robust solution for distributed energy needs.