A Review of Life Cycle Assessment for Fuel Cell Technologies: Advancing Clean Energy and Climate Solutions

Fuel cell (FC) technologies are often regarded as a sustainable alternative to conventional combustion-based energy systems due to their low environmental impact and high efficiency. Thorough environmental assessments using Life Cycle Assessment (LCA) methodologies are needed to understand and mitigate their impacts. However, there has been a lack of comprehensive reviews on LCA studies across all major types of FCs. This study reviews and synthesizes results from 44 peer-reviewed LCA studies from 2015 to 2024, covering six major FC types: alkaline (AFC), direct methanol (DMFC), molten carbonate (MCFC), proton- exchange membrane (PEMFC), solid oxide (SOFC), and phosphoric acid (PAFC). The review provides an updated overview of LCA practices and results over the past decade, while identifying methodological inconsistencies and gaps. PEMFCs are the most frequently assessed FC typology, covering 49 % of the studies, followed by SOFCs at 38 %, with no studies on DMFCs. Only 11 % of comparative studies carry out inter-comparison between FC types. Discrepancies in system boundary definitions across studies are identified, highlighting the need for standardization to enhance comparability between studies. Global Warming Potential (GWP), evaluated in 100 % of the studies, is the most assessed impact category. Fuel supply in the use phase, a major contributor to greenhouse gas (GHG) emissions, is under-assessed as it is usually aggregated with Operation and Maintenance (O&M) phase instead of discussed separately. GWP of energy production by all FC typologies spans from 0.026 to 1.76 kg CO₂-equivalent per kWh. Insufficient quantitative data for a meta-analysis and limited inter-comparability across FC types are noted as critical gaps. The study highlights the need for future research and policies focusing on green hydrogen supply and circular economy practices to improve FC sustainability.