Energy performance evaluation of Fuel Cell Heavy-Duty Vehicles for long haul applications: A study of the European fleet through VECTO simulations

The road freight sector is an important pillar of the European economy, as 75% of goods are transported on wheels, but it is also a significant source of CO2 emissions accounting for about 5% of the EU’s total greenhouse gas (GHG) emissions. The challenge of decarbonising this branch is particularly arduous, not only because of its inherent dependence on fossil fuels, but also because of the substantial increase in road freight activities year after year. For decades, the environmental impact of this sector, particularly in terms of GHG emissions, was largely overlooked. It was only in 2019 that a pivotal shift occurred with the adoption of the first CO2 emission standards for new heavy-duty vehicles (HDVs) within the EU, moving road freight transport towards carbon neutrality. Since the introduction of these regulations, the industry landscape has undergone profound transformations. The focus of research has pivoted towards the study of Zero Emission Heavy-Duty Vehicles (ZE-HDVs), propelled by the need to align with the ambitious objectives established by European regulations. Among the various innovations emerging in this space, hydrogen fuel cell-powered electric vehicles have garnered particular attention. These vehicles are increasingly viewed as a viable and promising solution for achieving the decarbonization goal of the road freight sector, making them a critical component of the future of green transport. The research performed in this thesis is contextualized within this transformation landscape, and it was carried out in collaboration with the Sustainable Transport unit of the European Commission’s Joint Research Centre (JRC). The central aim of this study was to conduct a comprehensive evaluation of the energy performance of HDVs engaged in long-haul operations, encompassing a broad range of use cases, and with a particular focus on hydrogen consumption, an aspect of paramount importance for fuel cell (FC) vehicles. The Vehicle Energy Consumption Calculation Tool (VECTO), the official European Commission's software for calculating the fuel and energy consumption of heavy-duty vehicles was employed to perform the vehicle simulations. An extensive literature review was undertaken to delineate the contemporary landscape of fuel cell technology and its application to this field, thereby providing a structured foundation for the entire work. The initial phase of the study involved the development of a VECTO model for a generic FC vehicle, representative of the heavy long-haul freight vehicle segment. A group 5 tractor-trailer, recognised as the most prevalent configuration across Europe, was reproduced. Following the model's validation against established literature data, its FC hybrid powertrain was integrated with the average characteristics of the conventional vehicles constituting the European reference HDV fleet, to recreate this fleet in FC-hybrid version through VECTO. A total of eight vehicles were reproduced and simulated for different mission profiles, designed to mirror the different real-life operational scenarios. The results of these simulations, which provide a reference framework for the energy behaviour of these innovative vehicles, were commented on and analysed. Finally, potential improvements in energy efficiency and operational adaptability of the fleet were assessed. This was achieved by first acting on the degree of hybridisation of vehicles, changing the battery size, and subsequently exploring the efficacy of a composite fuel cell system.