There is a worldwide debate about which energies are more efficient and renewable energy systems. This discussion comprises hydrogen and fuel cells as potential emerging technologies. However, information about hydrogen technology remains somehow unknown to a broader public. Currently some technologies supporting hydrogen productive chain are not so competitive and this means a tight bottleneck. Expectation is that this would be the most promising innovation in a new energy system based on renewable sources. This paper reports the large range of existing processes and technological routes for the production of hydrogen in many countries. Thus, this work aims to show the current energy landscape, highlighting the hydrogen and the main characteristics of the technological routes for its production. The overview about the current situation and trends of Hydrogen Economy is presented. The prominent research on hydrogen technology, processes and their main characteristics are addressed as well. The uncertainties surrounding the implementation of hydrogen energy, based on renewable sources, require further studies regarding competitiveness. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.