The Importance of Renewable Hydrogen in Decarbonization

Abstract

Hydrogen is an important industrial gas, representing a 10 million metric tons/year industry worth $100 billion. Currently over 95% of that hydrogen is made from fossil fuels: natural gas reforming or coal gasification. Close to 50% of the world’s annual hydrogen production is used for ammonia generation and oil refining, with the hydrogen generation being the highest energy and highest emission subcomponent of ammonia generation. In addition, 2% of U.S. energy currently goes through hydrogen as an intermediate, a number that will increase substantially when hydrogen fueled vehicles become widespread. In order to meet the Climate Action Plan goals of 80% reduction in greenhouse gas emissions by 2050, net zero carbon pathways for hydrogen production are therefore critical. There are several pathways to generating hydrogen from renewable sources, but one of the most advanced is membrane-based water electrolysis powered by solar, wind, or hydropower. While electrolysis has been demonstrated at megawatt scale, there is still significant promise for further improvement. Several countries are already committed to advancing this technology, and are working on the critical materials issues that drive cost and efficiency. Longer term technologies such as photoelectrochemical water splitting or thermochemical routes may provide lower cost pathways in the end, but need to build from technologies that have already been developed at relevant scale. The "perfect" technology to address the energy challenge will always be 20 years away. As new concepts moves from basic principles to bench scale experiments and beyond, the pitfalls become clearer. At the same time, dismissing existing commercial technologies on the basis of limitations which might become relevant at multi-gigawatt or terawatt scale prevents us from maximizing early impact on sustainability. This poster will focus on the need to leverage existing clean energy technologies in the near term to serve the megawatt and gigawatt scale, as building blocks and bridges to future technologies.