Local Hydrogen Production Key to Cutting Heavy-Duty Emissions

Heavy-duty vehicles, which currently account for one-fifth of global oil consumption, present a significant opportunity for reducing carbon dioxide emissions when powered by hydrogen instead of fossil fuels. A study from Chalmers University of Technology in Sweden highlights that locally produced green hydrogen offers the best climate benefits, while also promoting energy self-sufficiency for countries, especially during crises.

The research published in the journal iScience emphasizes that heavy-duty diesel trucks are the largest source of transport-related greenhouse gas emissions in the European Union. As demand for road transport is projected to increase, transitioning to hydrogen fuel is critical for global emissions reduction strategies.

Jorge Enrique Velandia Vargas, the study’s lead author and a former postdoctoral researcher at Chalmers, stated, “Hydrogen does not produce carbon dioxide when used in fuel cells, but we need to ensure that we do not shift emissions from one part of the life cycle to another.” The research evaluated potential future supply chains in Sweden and examined various technologies at each stage of hydrogen production and use.

The main conclusion reveals that utilizing hydrogen in heavy-duty vehicles significantly curtails carbon emissions compared to diesel. Yet, the method of hydrogen production and handling greatly affects its overall climate impact.

Blue vs. Green Hydrogen: Climate Considerations

One notable finding of the study is the comparison between blue hydrogen and green hydrogen. Blue hydrogen, derived from natural gas with carbon capture and storage, may have a larger climate footprint than green hydrogen, which is generated from water using renewable energy sources.

Maria Grahn, an Associate Professor at Chalmers, explained, “In theory, the production of blue hydrogen is climate neutral, but in reality, it is not. It is not possible to capture all CO2 after the conversion process.” She noted that 5 to 10 percent of carbon dioxide escapes into the atmosphere during production, and additional methane leaks occur throughout the supply chain.

Biomethane, another alternative, can potentially replace natural gas in hydrogen production. This renewable gas, derived from organic waste, may allow for hydrogen production that absorbs more carbon dioxide than it emits. However, the process still requires carbon capture infrastructure and energy, making the direct use of biomethane in trucks a more efficient option.

According to the study, green hydrogen emerges as the most favorable option. Its production involves using water as a raw material and renewable energy sources for electrolysis. Grahn highlighted that green hydrogen’s production and use generate minimal carbon emissions and can be manufactured globally, independent of local resources.

The Importance of Local Production

The study indicates that hydrogen production closer to refueling stations is more beneficial for the environment than establishing large central production facilities. Producing hydrogen on-site at refueling stations minimizes the energy and emissions associated with long-distance transport, which can be substantial.

“Hydrogen is the lightest of all the elements and does not ‘like’ to be transported,” Vargas noted. He emphasized that transporting hydrogen in gaseous form necessitates significant compression, while liquid hydrogen requires extreme cooling, both leading to energy losses and potential evaporation issues.

The researchers stress that proper conditions are essential for hydrogen to maximize its contribution to emissions reduction. Although the study focuses on Swedish conditions, its findings are applicable globally.

As the transport sector evolves rapidly, Vargas advocates for informed decision-making supported by thorough evaluations and life cycle analyses. “Every decision made has long-term consequences,” he added, underscoring the importance of informed policy in this critical area.

The findings of this research are aligned with the European Union’s goals, notably through the Alternative Fuels Infrastructure Regulation (AFIR) as part of the EU’s ‘Fit for 55’ climate package, which aims for a minimum 55 percent reduction in greenhouse gas emissions by 2030 compared to 1990 levels, with a long-term objective of climate neutrality by 2050.

As the world grapples with climate change, the transition to hydrogen-powered heavy-duty vehicles represents a pivotal step towards achieving both environmental and energy security goals.