A study by the URV highlights the potential of battery electric and hydrogen fuel cell trucks to reduce greenhouse gas emissions but also notes that, in many cases, biofuels are the least polluting option in the short term

Researchers from Universitat Rovira i Virgili have analysed the alternatives to diesel trucks in road freight transport and have determined their potential for lowering emissions of greenhouse gasses. The results of the study show that the use of hydrogen and electric trucks could reduce the emissions attributed to this sector by more than 45% by the end of the century and highlight biofuels as a cleaner alternative during this transition, as a premature change to electric vehicles could actually increase emissions by up to 70%. The analysis, which covered the entire life cycle of the technologies in question — from production to scrapping — has clearly shown that electric and hydrogen trucks could have a three to twelve times greater impact on people’s health than diesel trucks.

The road transport sector is one of the main sources of greenhouse gas emissions. According to the European Environment Agency, this sector accounts for 20% of all emissions in the EU, and it is estimated that freight transport emits one quarter of this figure. Forecasts suggest that, if current policies are not changed, emissions from freight transport will have increased 22% by 2050, making it difficult to meet the United Nations Sustainable Development Goals. This plan, endorsed by the European Union, promotes the development of sustainable infrastructures, clean and accessible transport systems and measures to combat climate change, among others.

Against this backdrop, researchers from the Department of Chemical Engineering have studied sustainable alternatives to diesel for road freight transport: the use of biofuels and the transition to battery electric and hydrogen fuel cell trucks. The environmental impact of each of these solutions varies depending on the availability of clean energy, the efficiency of the technology, the manufacturing processes and the materials used, among other factors.

To carry out a long-term analysis of these alternatives, researchers have used a methodology known as prospective life cycle analysis. “This analysis technique allows us to know the impact trucks will have throughout their entire life cycle; thus, it includes their manufacturing processes, fuel or electricity production and operation, as well as the handling of obsolete components”, explains Carlos Pozo, co-author of the research. As this is a prospective analysis, the researchers have taken into account forecasts on the evolution of clean energy sources when estimating future emissions of polluting gases.

The method has been applied using data from twelve regions around the world — Europe and the UK, North America, South America, China, the Middle East, India and others — and considering two possible scenarios: the implementation of policies that are a continuation of the current strategy (business-as-usual), which would lead to a global temperature rise of between 2 and 2.4 degrees Celsius by 2100; and the implementation of a rapid decarbonisation strategy with a zero emissions target, which would keep global warming below 1.5 degrees Celsius.

The results show the huge potential of electric and hydrogen trucks for reducing greenhouse gas emissions, given that their use would lower emissions by at least 45% in all scenarios. Notwithstanding this, the research highlights the importance of biofuels in the transition to electric and hydrogen: “In the short term, the wisest alternative in most cases is biofuels; they can lower emissions by almost 30%, but they have their limitations if we want to achieve climate neutrality”, says Pozo. Therefore, the best strategy to reduce emissions is a gradual transition to battery electric and hydrogen fuel cell trucks. Thus, the idea is to harness biofuels while decarbonising electricity and hydrogen production.

The right time

If the transition to electric and hydrogen trucks happens too quickly, some regions could see a 70% rise in cumulative greenhouse gas emissions by 2030, according to the predictions. Researchers caution that this is particularly concerning in areas where electricity is primarily generated from non-renewable sources. They point out that if the transition to these technologies takes place at the right time, it could avoid a global temperature increase of 0.2 to 0.3 degrees Celsius.

The question then is, when will be the best time to carry out this transition? The answer depends on the region of the world in question and the strategies being implemented. Under current policies, in regions with a high share of renewables in electricity production – such as the European Union and Latin America – the window may start to open as early as this year. On the other hand, regions such as Japan and China would not reach this optimal transition point until after 2035 and 2040, respectively. If rapid decarbonisation policies were adopted, all the areas analysed would reach the optimal transition point before 2035.

An environmentally friendly technology… that is more dangerous to humans?

The results predict that the widespread use of both battery-electric and hydrogen-cell electric trucks may have a greater impact on human health than their diesel equivalents. Although they have no exhaust emissions, electric trucks could be three times more hazardous to health, while hydrogen-cell trucks could have a thirteen times greater health impact. This is due to non-renewable energy production processes, the release of hazardous components in battery manufacturing and the increased weight of the vehicles, which leads to increased emissions of particulate matter from brakes and tyres.

The large-scale implementation of this technology also brings with it a demand for metals and semiconductors that the researchers find concerning: “We need to improve the processes for recovering materials to avoid a situation where the scarcity of the same limits the implementation of these technologies”. The simple fact is that the manufacture and upkeep of electric trucks requires a lot more of our limited resources than in the case of diesel trucks.

Reference: Richard Cabrera-Jiménez, Josep Maria Mateo, Laureano Jiménez, Carlos Pozo, Prospective life-cycle assessment of sustainable alternatives for road freight transport, Renewable and Sustainable Energy Reviews, Volume 211, 2025, 115243, ISSN 1364-0321, https://doi.org/10.1016/j.rser.2024.115243