Hydrogen, energy vector for the future? Or, on the contrary, limited to its current applications in the field of chemistry and refining for decades to come, possibly even until the end of the century? There is much controversy over this issue and two sides to the argument. Advocates of the hydrogen civilization consider that, following a technological revolution hydrogen will play a universal role alongside electricity as a substitute for fossil fuels, especially (but not only) in transport, leading to radical elimination of CO2 emissions. For the skeptics, and even outspoken opponents, hydrogen will remain restricted to its current applications due to the insoluble problems inherent to its generalized use, especially in transport. This book highlights the increasing and inevitable role of "energy" hydrogen – as opposed to chemical hydrogen – in the key sectors of transport and "clean" electricity production.