Preface to the special issue on the World Hydrogen Energy Conference – WHEC2018

The world is experiencing in this beginning of century an important energy transition from fossil fuels to renewable energies and to the hydrogen energy. This is motivated by several concomitant factors such as the growth in geometric scale of the world demand for energy, the low energy security offered by fossil fuels based sources, the prospects for strong world populational growth with increasing social inequality, the energy inefficiency associated to the present technological processes inducing significant energy losses, as well as the present well-accepted concept that anthropogenic effects accumulate planetary contamination with unprecedented levels, capable of harmfully affecting the humanity, the biodiversity, the climate, the environment as a whole as well as our planet. In the same venue where the United Nations held a seminal environmental Earth Summit in 1992, which sought to raise awareness on climate change issues, the 22nd World Hydrogen Energy Conference, WHEC2018, took place in Rio de Janeiro, Brazil, from June 17th to 22nd 2018 with the motto Power and Biomass to Hydrogen with almost 800 representatives from 51 different countries.

What a great challenge and what a fantastic endeavor it is to conceive, organize and hold such an important conference! And it is still more significant to do so when we clearly see that the fossil fuels era resists with its tremendous and dominant worldwide power at the same time that a new perspective is unveiled with the present effective dawning of the hydrogen energy era. Hydrogen energy is the solution for the huge present and future energy requirements. It consists of utilizing hydrogen and hydrogen-containing compounds to generate energy to be supplied to all practical uses needed with high energy efficiency, overwhelming environmental and social benefits, as well as economic competitiveness as mass production and deployment occur. From now on, we will witness a progressive share of the world' s energy matrix shifting towards efficiency, cleanness, more silent and environmentally friendly technologies. We will get more used to deal with renewable energies, with power to gas industrial procedures and with the increasing use of biomass at the same time that fuel cells are introduced in a daily basis utilization to become the main energy converters of the 21st century. Conceiving the program for the WHEC2018 has represented a major task for the organization of the event and was somewhat facilitated by the decision to edit a book on hydrogen energy, “Science and Engineering of Hydrogen-Based Energy Technologies”, published by Elsevier electronically in 2018 and in printed form in 2019. The book chapters' lent their titles to the event main sessions: hydrogen energy; fuel cells; hydrogen production from biomass; power to hydrogen and hydrogen storage; engineering application and products; market, commercialization and deployment; safety, code, standards and roadmaps. The ever-present encouragement and direction given by the International Association for Hydrogen Energy and several members of its Board of Directors was assuring to bring confidence.

A selection of the papers presented at the WHEC2018 are herein published after thorough peer-reviewing procedures. As editors of the present edition, we are indebted to the reviewers who lent their professional knowledge to such an important voluntary work. We also thank the International Journal of Hydrogen Energy for the efficient editorial support and do hope the contents that are unveiled in each of the papers will attract scientific and technological interest.