Reduction of carbon dioxide emissions and other pollutants is a critical need worldwide for sustainability.  Transportation is one major contributor of greenhouse gas emissions, and there is significant debate over the relative merits of fuel cells vs. batteries as the energy system.  Batteries provide improved energy efficiency, but do not provide the driver with the same experience in range and fueling time as the fuel cell option.  However, a major drawback for fuel cells is the lack of hydrogen fueling infrastructure.  While even hydrogen from natural gas provides a well to wheels emissions benefit, hydrogen from non-carbon based sources has had challenges in being viewed as a cost effective option, largely because the electricity cost dominates the analysis.

While much attention has been directed towards hydrogen as a transportation fuel, it should also be remembered in developing global solutions that hydrogen is also a major world chemical feedstock.  Most of the world's hydrogen goes to hydrogenation of fats and oils, and ammonia generation.  Production of ammonia is one of the world's largest consumers of energy, largely based on the energy consumed in the generation of hydrogen from natural gas.  The Haber Bosch process occurs at high pressure (150–300 atm) and high temperature (400°–500°C), and accounts for about 1-2% of the world's annual energy consumption (5% of the world's natural gas). In addition, the fossil fuel reforming of natural gas to hydrogen results in substantial carbon dioxide (CO₂) emissions. 

Hydrogen production from water electrolysis requires more energy per kilogram of hydrogen than natural gas reforming (when only considering the generation step), but has the option of using renewable energy as the primary energy source.  In addition, polymer membrane-based electrolysis is very well suited for load-following applications.  These devices can therefore operate primarily on excess electricity from what would otherwise be stranded renewable resources.  Finally, because an electrolyzer is a flow cell, like a flow battery, the reactants and products are stored separately from the electrochemical device, which is more attractive for very long charge times.  Higher capacity can be added simply by adding storage tanks.  This talk will discuss the current status of electrolysis and challenges in bridging the gaps between present commercial status and future optimized solutions in this context.

In addition, an analysis of energy of manufacturing for electrolyzers themselves shows opportunities for improvement.  One energy intensive process is the manufacture of the membrane electrode assembly.  The energy required to deposit and bond the catalyst to the membrane can be reduced through advanced manufacturing processes, and use of less catalyst reduces the original refining energy, which is also a significant contribution.  Progress in reduction of manufacturing energy will also be briefly discussed.