What Could the Future of Zero Emission Haulage Look Like?
That’s the question we set out to answer when we embarked on Project ICEBreaker, developing a Hydrogen Fuel Cell (FC) powertrain for a 40t HGV tractor unit as part of the Advanced Route to Market Demonstrator Programme (ARMD2), part-funded by the Advanced Propulsion Centre (APC), working with project partners HORIBA MIRA and Intelligent Energy.
The objective of the ARMD competition is to deliver 12-month sprint projects to accelerate the development of technology, and that’s exactly what this project did. Starting in October 2023, together with our partners, we went from a blank sheet of paper to retrofitting a 40t Internal Combustion Engined Volvo tractor unit with a FC powertrain, which we presented at the CENEX Expo show in September 2024
Three key criteria guided the design of the powertrain:
Optimised Packaging
The UK market presents a particular challenge due to a more restricted total vehicle length, so to ensure fleet operators could use a full range of standard ISO trailers, we had to avoid stacking pressure vessels on the back of the cab, as the majority of other FC HGV’s have to date.
Mass (Weight)
To date, Zero Emission HGVs have struggled to provide a payload capacity equivalent to Internal Combustion Engined (ICE) HGVs. This is an important issue because compromising the available payload for operators can reduce their operating margins and potentially result in more trucks on the road. So, mass parity with the ICE donor vehicle was a primary goal.
Safety
With any new technology, safety is a key consideration, and with 700bar hydrogen storage and a High Voltage Battery on the vehicle, it was critically important to develop appropriate safety concepts and working practices to ensure the safety through the build and operation of the truck.
What does a Fuel Cell Powertrain consist of?
Fuel Cell
A FC generates electricity through a chemical reaction between hydrogen and oxygen in the atmosphere, the only byproducts from which are heat and water. Electricity from the FC (i) Powers the electric motor which drives the vehicle, (ii) charges the vehicle’s battery, and (iii) powers ancillary systems.
For this project, we used 2 x 100kW FCs developed by Intelligent Energy, utilising their propriety evaporative cooling process, which enables rapid power changes in the FC.
Battery Pack & Battery Management System
Fuel Cell Electric Vehicle (FCEV) typically include a battery pack as part of the powertrain to (i) support start-up of the FC, (ii) capture energy from regenerative braking, and (iii) manage transient phases, such as acceleration or when the vehicle is climbing or braking.
For this project, Viritech developed a bespoke 800V battery pack using a power-dense LTO chemistry cell (less prone to thermal runaway and inherently safer than NMC and LFP cells), providing great durability at high power outputs and capable of operating at temperatures down to -30 degrees Celsius.
To manage rapid changes in charge and discharge, Viritech developed a high-sampling frequency battery management system (BMS), which monitors and manages the safety features on the pack and provides State of Charge information to the Vehicle Control Unit (VCU).
DC-DC Converter
A key challenge with FCs is managing losses due to resistance and managing cable sizes. Our preference is to operate with higher voltage and lower current, but FCs output low voltage at a high current. So, to manage this and ensure the output voltage of the FC remains above the battery pack voltage and preserves charge, the powertrain includes a DC-DC converter, which steps up the FC voltage and reduces the current.
As part of this project, Viritech developed a DC-DC converter, optimised for the current and voltages of FCEVs, which is smaller, lighter and more cost-effective than other competitor products.
Pressure Vessels
Hydrogen is typically stored on a vehicle as a pressurised gas in Pressure Vessels (PVs) capable of storing at up to 700bar, reduced through pressure regulators to 12bar when it enters the FC. For this project, we used 2x Type IV Carbon-composite Overwrapped Pressure Vessels (COPVs) capable of carrying a total of 30kg of hydrogen.
COPVs are subject to stringent testing standards to ensure hydrogen is stored safely, and in this project, we used a Viritech developed hydrogen control unit to monitor temperature and pressure in the PVs and to communicate with the fuel station to ensure safe refuelling.
Thermal System
Thermal systems on FCEVs are typically more challenging than on ICE vehicles, which can eject a significant amount of heat via their exhaust and operate at a higher temperature, creating a significant temperature delta, which increases heat rejection.
On this project, HORIBA MIRA developed the vehicle cooling systems based on significant simulation work, to ensure the vehicle would function optimally in all realistic scenarios.
E-Machine/Inverter
An E-machine/Inverter is used to convert electrical energy from the FC and battery into mechanical energy to drive the vehicle wheels, and during deceleration, reverses the process to convert mechanical energy into electricity, which is stored in the battery.
One area of compromise on this project was the lack of availability of a suitable E-Axle as an integrated unit, and as a result, we used a dual-motor setup to drive the differential via the original prop shaft. Had a suitable E-Axle been available, it would have enabled a further reduction in vehicle mass and provided space to package an additional COPV, further increasing the range of the vehicle.
Range
This successful project delivered a FC HGV, which has achieved the key targets of weight parity with the ICE donor vehicle, with the ability to tow any ISO trailer. With commissioning trials set to commence shortly, we do not yet have validated performance figures, but simulations indicate that even on arduous routes, the truck will achieve a range of 300km with its current capacity of 30kg of hydrogen, which can be increased to 500km with the addition of an E-axle, giving additional COPV storage capacity.
Conclusion
Having set out to demonstrate the future potential of hydrogen-powered zero-emission HGVs, Project ICEBreaker has delivered a compelling case. Working with an OEM partner and fleet operators, Viritech plans to continue the development of the Project ICEBreaker powertrain in a Phase 2 project, which aims to deliver commercially viable HGVs by 2028.
So, with further investment and government support for the roll-out of hydrogen infrastructure commencing through programmes such as ZEHID, hydrogen is now clearly on track to become a commercially viable option for fleet operators seeking to transition to zero-emission haulage.
Chris Hübel
Head of Engineering
As Head of Engineering, Chris brings over 20 years of experience in mechanical systems and design engineering across the automotive, aerospace, and motorsport sectors. He is responsible for defining and disseminating engineering best practices, processes, and standards, uniting technology strategy and implementation across projects to foster collaboration and maximise efficiency.
