Clean hydrogen is emerging as a key component of the global transition to clean energy, offering a sustainable alternative to fossil fuels. It can help boost energy security, improve air quality, and support decarbonization, particularly in industries where emissions are hard to abate, such as steel, cement, and chemicals. Clean hydrogen is produced via renewable-energy-based electrolysis (green hydrogen) or natural gas reforming with carbon capture (blue hydrogen), which significantly reduces carbon emissions. For developing countries with abundant renewable resources, green hydrogen presents an opportunity for economic growth, job creation, and energy security by reducing reliance on imported fossil fuels. Similarly, countries with natural gas reserves can benefit from blue hydrogen. However, scaling up the clean hydrogen economy requires stable demand and significant investment to reduce production and distribution costs. Global hydrogen demand, which reached 97 million tonnes (Mt) in 2023, is concentrated in the refining and chemical sectors. Clean hydrogen played only a marginal role, with less than 1 Mt production in 2023, although production is projected to grow strongly, reaching 49 Mt a year by 2030. This growth in demand can lead to potential cost reductions, which can have a spillover effect and help to simulate demand for hydrogen in the transport sector. This report assesses the economic viability of FCEVs in five selected countries (Brazil, Chile, India, South Africa, and the Republic of Korea) through comprehensive modeling exercises. It provides a comparative analysis of BEVs, FCEVs, and internal combustion engine vehicles (ICEVs) across four key vehicle segments: passenger cars, light commercial vehicles (LCVs), buses, and heavy-duty vehicles (HDVs).