System approach to natural versus manufactured hydrogen: An interdisciplinary perspective on a new primary energy source

Abstract

Hydrogen gas (H2) is currently widely investigated in the context of the energy transition as a means of storing energy production in particular from renewable and intermittent sources. However, such manufactured H2 is not a primary energy source but an energy carrier of other primary sources. The idea that natural H2 sources could exist on Earth and represent a potential source of primary energy had long been neglected in absence of empirical evidence. Recent geological surveys in many parts of the world provide increasing evidence that specific geological processes can lead to significant natural H2 generation. The objectives of this study are to synthetize information on natural H2 generation patterns based on geoscience literature and discuss societal implications, from an interdisciplinary perspective, of potential large-scale deployment of natural H2 operations. Based on current knowledge, we suggest that natural H2 presents contrasting features compared to current dominant energy sources, and may potentially contribute to a gradual emergence of energy system decentralization. We discuss differences and common features between natural and manufactured H2 systems and point out technical, social and economic opportunities and challenges. Overall, we argue that natural H2 is an emerging primary energy source with promising opportunities for the energy transition, and may involve a change of paradigm in the interplay between society and energy systems.