There is growing societal consensus that hydrogen is an absolutely necessary part of energy portfolio to reach the COP26 goal to secure global net-zero by mid-century. Hydrogen will play a major role in hard to decarbonize sectors such as industrial (production of steel, cement, and chemicals including ammonia) and heavy-duty, long-haul transportation. By different estimations, hydrogen production volume will be anywhere from 240 to 800 million metric tons per year (MMTY). More realistic predictions are in the range 500 – 600 MMTY that is 7 – 8.5 times more than current global hydrogen production, which predominantly uses fossil fuels and emits around 830 MMTY of carbon dioxide. It is assumed that hydrogen produced by water splitting became predominant by 2050.

With less than 0.1% of current global hydrogen production delivered from water electrolysis, electrolytic hydrogen has tremendous potential for growth. Two commercial (alkaline and PEM) and two emerging (SOEC and AEM) will be compared based on current status and trends of technology (catalysts, membranes, system manufacturability, and capital cost). These technologies could benefit from the integration with energy sources (e.g., nuclear power) or downstream utilization (e.g., ammonia production). Suitability of these technologies for exemplary environments with different energy inputs, electricity prices, and capacity factors will be analyzed. In addition, the effect of different pathways for hydrogen delivery (pure and in the form of a hydrogen carrier) on the levelized cost of hydrogen will be considered.

Development of advanced green hydrogen technologies including early stage research will be illustrated with projects funded by DOE Advanced Research Projects Agency (ARPA-E) and Hydrogen and Fuel Cell technologies Office (HFTO), and their role in DOE Hydrogen Program and Hydrogen Earthshot will be discussed.