Synergistic Interaction Between Water Resource Recovery Facilities and Renewable Hydrogen Generation.

As of today, about 85% of the global energy consumption originates from non-renewable sources, such as coal, natural gas, and oil (Abdalla et al., 2018). The imperative need to mitigate climate change impacts has led to collective efforts towards the de-carbonization of the increasingly growing energy sector. The progressive implementation of renewable technologies, such as wind and solar photovoltaic, in the energy market is part of the ongoing strategies adopted by various worldwide climate action programs (Williams et al., 2012). Although renewables are virtually unlimited compared to fossil energy sources, their reliability is constrained by their intermittent and fluctuating dynamics (Colbertaldo et al., 2019). Therefore, much attention has been posed on the ability to store renewable energy in order to balance electrical grid operations and preventing energy curtailment. Power-to-gas (P2G) is currently among the most studied energy industry alternatives to store energy (Colbertaldo et al., 2019). In P2G systems, electrolyzes can be used to electrochemically split the water into oxygen and hydrogen using excess renewable energy (see Fig.1). The resulting renewable hydrogen generated (also known as green hydrogen) can be stored, and eventually used during periods characterized by lower renewable temporal availability either directly as process gas or via hydrogen fuel cell (HFC) systems to generate electrical power during periods of deficit on the electric grid. A different fate is typically reserved for the pure oxygen stream, which is usually vented to the atmosphere.