Direct methanol fuel cells (DMFCs) electrochemically oxidize methanol (CH3OH) to generate electricity, offering several advantages over hydrogen systems including ambient temperature liquid fuel storage, existing distribution infrastructure compatibility, and simpler system integration. DMFCs operate at 60-120°C using proton exchange membranes similar to hydrogen fuel cells, with methanol fed directly to the anode where platinum-ruthenium catalysts facilitate oxidation. The technology achieves energy densities of 3000-4000 Wh/L - substantially higher than lithium batteries - enabling extended operating ranges without heavy battery packs. Methanol production from renewable sources (biomass gasification, CO2 hydrogenation using green hydrogen) creates carbon-neutral fuel cycles, while fossil methanol from natural gas provides a transition pathway. DMFCs suit applications including portable power (laptops, military equipment), auxiliary power units for vehicles, and marine propulsion where methanol's liquid form simplifies fuel handling compared to hydrogen or compressed natural gas. Methanol internal combustion engines offer an alternative approach, requiring modifications similar to ethanol engines but burning cleaner with reduced particulate emissions. Methanol-to-hydrogen reformers convert methanol onboard vehicles into hydrogen for conventional PEM fuel cells, leveraging methanol's infrastructure advantages while utilizing mature fuel cell technology. Economic competitiveness depends on methanol prices (200-400 dollars per tonne) relative to gasoline and diesel, with green methanol production costs declining as renewable electricity becomes cheaper. Safety considerations address methanol's toxicity and flammability, though these risks are comparable to gasoline with appropriate handling procedures.