In the development of hydrogen vehicle technologies, the automotive industry adopts a portfolio approach; a multitude of technological options is developed for hydrogen storage and conversion. Patent portfolios of car manufacturers are used as indicators of the variation and selection dynamics of different options. Convergence towards a single combination of storage and conversion technologies would indicate closeness to commercialization of hydrogen vehicles. Even though patent portfolios converge towards a single conversion option, the PEM fuel cell, storage patents only show divergence. This is very different from hydrogen prototype vehicles that have shown strong convergence towards high-pressure storage. These findings raise questions about the commercialization of hydrogen vehicles, as the industry is still searching for promising storage methods. As on-board storage methods are still in development, hydrogen refilling stations would best be kept open to all options rather than high-pressure systems alone. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.