HYDROGEN is gathering support as a potential replacement for fossil-based fuels such as coal, oil, and natural gas. In theory, and for most applications, this is an attractive option: a relatively plenteous material whose use causes only a small environmental disturbance compared to, for instance, airborne emissions of carbon dioxide or particulate materials (PM2.5 and PM10). Unlike fossil-based fuels, hydrogen needs to be processed out of something else and delivered to the point of use. This article describes some of the delivery options, the factors that can influence the choice, and some of the associated challenges. Transporting almost any fluid requires for a number of questions to be asked, perhaps the most relevant of which are: How much? How pure? What pressure? Clearly the answers to these will depend on the end use. For most applications, hydrogen will be used as a gas, but that does not mean that it is always transported as a gas. The majority of the hydrogen moved around has been in steel cylinders or in specially-designed and refrigerated tube trailers. Single cylinders typically contain typically 5-8 Nm3 of hydrogen at pressures ranging between 150–300 bar. BOC ha...