Zero-emission transportation and aviation through green hydrogen innovation

In today's dynamic energy landscape, the shift toward sustainable sources is more urgent than ever. Among emerging solutions, green hydrogen stands out especially for hard-to-decarbonize sectors like transportation and aviation . Sustainable hydrogen originates by electrolysis through renewable energy, providing a zero-carbon substitute for conventional hydrogen, which is primarily generated by carbon-intensive steam methane reforming . Hydrogen's unique properties such as a high energy-to-weight ratio and compatibility with existing infrastructure make it more than just a clean fuel. It represents a paradigm shift in how energy is produced, stored, and used. According to the authoritative International Energy Agency (IEA), by 2040, worldwide consumption of energy could increase by as much as 30 %. Considering this prerequisite with fossil fuels would only worsen climate change, making green hydrogen not just viable but essential. Despite its promise, challenges persist. Safety concerns around hydrogen's flammability have been addressed through modern handling protocols However, its low volumetric energy density presents storage and transportation issues—particularly in aerospace. Encouragingly, technological advancements in high-pressure tanks, cryogenic systems, and solid-state hydrogen carriers are enhancing feasibility and safety. This review examines the potential and challenges of green hydrogen, with a focus on its application in aviation. It highlights advances in fuel cells, liquefaction, and hydrogen storage that enhance efficiency and safety. Hydrogen-powered aircraft prototypes show projected emission cuts of 50–75 % compared to conventional jet fuels. The review identifies key challenges—scaling infrastructure, reducing costs, and regulatory alignment—and proposes solutions including investment incentives and global safety standards. It also outlines future research directions in materials, hybrid propulsion, and life-cycle assessment, reinforcing green hydrogen's role in sustainable aviation. • Hydrogen can blend with aviation fuels, enabling low-emission flight without major infrastructure changes. • Green hydrogen from renewables is a zero-carbon alternative to grey hydrogen, crucial for decarbonizing aviation. • Non-CO 2 emissions like water vapor and NO x from hydrogen aircraft impact climate forcing and need careful management. • Hydrogen enables long-term energy storage and boosts resilience in transport, industry, and homes, advancing the clean energy shift.