Preface-JES Focus Issue on Electrolysis for Increased Renewable Energy Penetration

(First paragraph) Today represents a particularly exciting time, as our planet’s energy system is undergoing major changes due to dramatically decreasing renewable energy prices and increasing societal concerns over greenhouse gas emissions, criteria pollutants (arsenic, mercury, NOx, particulate matter), and climate change. These factors are pushing society toward deep decarbonization of our energy system, perhaps the most challenging issue facing the planet today. Unfortunately, wind and solar energy, while both promising generation sources, come with intermittency challenges and have limitations in their abilities to impact industrial and transportation sector demands where fossil fuel energy carriers based on chemical bonds have provided the basis for historic energy demands. Electrolysis (Hydrogen Generation) offers the potential to meet the multi-GW demand for both grid-balancing and input into the industrial and transportation sectors, as shown schematically below. In such an energy system, hydrogen acts as an energy carrying intermediate that parallels electons (electricity) within the energy system. Therefore interest in this area has increased significantly with focus on several different technological approaches, each with their own unique challenges