The transportation sector is a significant player in global carbon dioxide (CO2) emissions, and it offers a tremendous opportunity for advancing decarbonization initiatives. To achieve a zero-emissions global supply chain, we must rethink our dependence on a heavy-duty trucking industry responsible for emitting 810,000 tons of CO2, equating to 6 percent of greenhouse gas emissions in the United States and consuming 29 billion gallons of diesel each year.
A groundbreaking study by researchers at MIT, presented at the recent American Society of Mechanical Engineers 2024 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, evaluates how the design range of zero-emission trucks affects energy storage requirements and operational revenue. This multivariable model empowers fleet operators and owners to comprehend the design factors that influence the economic feasibility of battery-electric and hydrogen fuel cell heavy-duty trucks, enabling informed decisions for fleet transitions.
“The challenge of decarbonizing trucking is like a large, complex pie. Our academic role is to quantify different segments of that pie using modeling based on insights from industry stakeholders,” explains ZhiYi Liang, a PhD student focused on renewable hydrogen at the MIT K. Lisa Yang Global Engineering and Research Center (GEAR) and lead author of the study. This paper, co-authored by Bryony Dupont and Amos Winter, the Germeshausen Professor at MIT’s Department of Mechanical Engineering, sheds light on the operational and socioeconomic factors critical to successfully decarbonizing heavy-duty vehicles (HDVs).
Operational and Infrastructure Challenges
According to the team’s model, a key technical challenge lies in the necessary energy storage on trucks to meet the range and towing performance required for commercial applications. Given the high energy density and affordability of diesel fuel, existing diesel drivetrains are currently more viable than lithium battery-electric vehicle (Li-BEV) and hydrogen fuel-cell-electric vehicle (H2 FCEV) alternatives. While Li-BEV systems offer superior energy efficiency, they are limited to short to medium-range routes (under 500 miles) with reduced freight capacity due to heavy onboard energy storage requirements. Moreover, the existing electric grid infrastructure needs significant enhancements to facilitate the large-scale deployment of Li-BEV HDVs.
Although hydrogen-powered drivetrains possess a weight advantage allowing for enhanced cargo capacity and longer routes exceeding 750 miles, the current state of hydrogen infrastructure limits their economic viability. Economic considerations, including operational costs and anticipated revenue, highlight the need for government support in the form of incentives and subsidies to reduce hydrogen prices significantly. Continued corporate investment is vital to establishing a stable hydrogen supply. Additionally, the ongoing development of conformal onboard hydrogen storage systems—central to Liang’s PhD work—remains essential for successful integration into the HDV market.
The efficiency of diesel systems stems from decades of technological advancements, suggesting a similar trajectory for alternative drivetrains is possible. However, interactions with fleet owners, automotive manufacturers, and refueling providers reveal a complex web of interdependencies that must be addressed simultaneously—from renewable fuel infrastructures to technology readiness and the capital costs associated with new fleets. As various sectors grapple with an uncertain future in which no single entity controls the outcomes, the situation presents significant risks.
“In addition to infrastructure constraints, we currently only have prototypes of alternative HDVs available for fleet operators, resulting in high procurement costs that dampen demand for automakers to scale up manufacturing,” Liang explains. This creates a challenging cycle that is difficult to break, particularly for stakeholders striving to remain competitive in a free market.
Quantifying a Path to Feasibility
“Industry professionals recognize that an energy transition is essential, yet they often lack clarity about the most viable path forward,” Liang remarks. While there is no one-size-fits-all solution to achieving zero emissions, the new model offers a valuable tool for quantifying and evaluating specific aspects that facilitate informed decision-making.
Other MIT-led initiatives aimed at supporting industry players in navigating decarbonization challenges include an interactive mapping tool developed by Danika MacDonell, Impact Fellow at the MIT Climate and Sustainability Consortium (MCSC), along with Florian Allroggen, executive director of MIT’s Zero Impact Aviation Alliance, and a team of undergraduate researchers. The MCSC’s Geospatial Decision Support Tool facilitates strategic decisions for fleet operators, offering a visual representation of regional freight flow densities, costs, emissions, and existing infrastructure, along with relevant regulations and incentives.
Although existing limitations underscore the necessity for collaborative problem-solving across sectors, the authors are optimistic about stakeholders’ enthusiasm to confront climate challenges together. Recently, notable collaborations, such as the agreement between General Motors and Hyundai to explore future cooperation on clean energy initiatives, reflect a cultural shift toward collaboration within the industry.
Liang emphasizes that transitioning to zero emissions in the transportation sector is merely one facet of a broader “energy revolution” requiring interconnected efforts across all sectors. “Everything is connected. To achieve meaningful change, we must see ourselves as part of the larger system that needs transformation,” Liang states. “You cannot create a successful revolution independently.”
The authors extend their acknowledgments to the MIT Climate and Sustainability Consortium for facilitating connections with industry members in the HDV ecosystem, and show gratitude to the MIT K. Lisa Yang Global Engineering and Research Center and the MIT Morningside Academy for Design for their financial support.
Photo credit & article inspired by: Massachusetts Institute of Technology
