• Just some context

    Green hydrogen production will consume 1.5 ppm of Earth’s freshwater or 30 ppb (0.03 ppm) of saltwater each year, an amount smaller than what is currently consumed by fossil fuel-based energy production and power generation. If desalination by RO is utilized, the additional energy requirement would be less than 0.2% of the minimum energy required to produce the hydrogen by electrolysis, and the energy cost would add approximately $0.01 to the price of hydrogen per kg. These numbers suggest that water supply will not be the limitation for electrolyzers, and we should instead continue to focus on technological improvements for the energy efficiency of electrolyzers, which is currently the limiting factor and has the potential for significant advancements. While the concern about the “water problem” is much more prevalent in the journalistic community than among scientists, journalism can have a significant influence on the acceptance of hydrogen as a growing market. It is therefore essential that we rigorously characterize the true water requirement of electrolysis technology, without the influence of water needs for the current non-renewable infrastructure, to get a clear idea of the impact hydrogen can have on a renewable energy future.