An evaluation of renewable hydrogen production technologies anticipated to be available in the short, mid- and long-term timeframes was conducted. Renewable conversion pathways often rely on a combination of renewable and fossil energy sources, with the primary conversion step relying on a completely renewable source and the auxiliary steps using a more readily available energy mix such as grid electricity. The conversion technologies can be broadly classified into four categories based on the primary conversion mechanism: thermal processes, electrolytic processes, photolytic processes, and biochemical processes. Based on anticipated technology readiness, water electrolysis and biogas reforming pathways will be available in the near term whereas biomass gasification and bio-derived liquids reforming pathways are expected to be available in the mid-term. Photolytic and dark fermentation approaches are still in the research stage and must go through significant development and demonstration.
