Multi-objective optimization of proton exchange membrane fuel cell based methanol-solar-to-X hybrid energy systems

This study introduces a novel “methanol-solar-to-X" hybrid energy system based on proton exchange membrane fuel cells (PEMFC), a promising approach for distributed energy generation. By integrating renewable energy into the methanol-driven PEMFC system, we aim to minimize annual costs and reduce environmental impact. Traditional methods, such as “solar-to-singular energy conversion”, limit the effective coupling of solar and methanol energy. To address this, we developed an enhanced heat integration module within a multi-objective mixed-integer nonlinear programming framework to optimize solar integration sites and improve system performance. A numerical model was implemented in GAMS for a 1000-kWe combined cooling, heating, and power (CCHP) system, evaluating energy, economic, and environmental outcomes. Results indicate significant enhancements with the SCCHP-TS system, achieving a 7.03% reduction in the levelized cost of electricity (LCOE) and a 10.95% decrease in carbon mass specific emissions (MSE) compared to the conventional methanol-fueled methanol-reforming PEMFC-based system. Additionally, comprehensive solar integration across the site yielded improvements of at least 4.30% in energy efficiency, 4.23% in LCOE, and 4.81% in MSE relative to component-specific solar designs.