On October 6, 2025, the Yale School of the Environment published an analysis that puts biomass-based hydrogen back on the map. The core idea is simple: biohydrogen can reduce emissions in industry and transport more quickly in the years before electrolysis is fully scaled up. This makes the route relevant as an accelerator, alongside the growth of green energy and new electrolyzers.
Hydrogen provides energy without direct CO2 emissions. The true climate impact depends on how the hydrogen is produced. Currently, most of it comes from high-emission natural gas. The United States produces a significant portion of the world's hydrogen. The Yale authors demonstrate that improvements can be made by looking at the pathways more broadly.
The research combines life cycle analysis with the GCAM energy system model. This takes into account both supply and demand, as well as the role of policy. The team calculates options with electrolysis, Bio H2, and various incentives. The result is striking. If Bio H2 is allowed on the market, the total emission reduction between 2025 and 2050 will be approximately 1,6 to 2 times greater than in scenarios without this option. The greatest gains will occur in the coming decade, when demand for hydrogen increases and electrolysis is still under development.
Electrolysis can be very clean using renewable energy. Scaling it up, however, faces high investment costs and scarcity of space and water. Moreover, US policy is changing in the coming years. Support programs are being tightened, meaning projects with long lead times will benefit less. In this context, Bio H2 proves to be a useful addition, as the technology and supply chains are already available.
The raw materials for Bio H2 are diverse. Agricultural and forestry residues are preferred because they place minimal additional pressure on land. Energy crops such as switchgrass and miscanthus are also a viable option, provided they are properly integrated. Using forest residues can also help reduce fire-prone forest accumulation. The researchers explicitly place this within a circular bioeconomy.
The study also points to policies that can stimulate demand. A broad CO2 price seems unlikely in the United States in the short term. Sector-specific incentives, such as those for steel or fertilizer, could then have a faster effect than generic instruments. The goal is not a competition between routes, but a portfolio approach that eliminates more emissions in less time.
Using Bio H2 requires attention to sustainability, logistics, and quality. Residual flows are prioritized, with clear agreements regarding competition with material applications and biodiversity. In practice, Bio H2 often comes from the gasification of dry biomass with gas purification and sometimes with CO2 capture and storage. This can further reduce net emissions. Specifications and impurities are also important for customers, so that installations can be designed based on known values.
Yale's message is down-to-earth. Don't choose between electrolysis and biomass, but develop both routes in parallel. Bio H2 accelerates the reduction in the years leading up to 2035, while the rollout of green electricity and electrolysis continues. This will create a robust market for clean hydrogen, bringing the 2050 target closer.
Source: Yale School of the Environment
