Along with battery electric trucks, hydrogen trucks are emerging as a possible solution in the quest for lower-emissions transportation.  

The technology has been in use here in New Zealand since 2022, when NZ Post’s zero-emissions hydrogen fuel cell truck hit the road. Meanwhile, transport company HW Richardson is commercialising its offering for dual fuel trucks that have been converted to run on hydrogen as well as diesel – a solution that it has found lowers a vehicle’s carbon emissions by around 30%. 

Read on to learn more about these two technologies and how the trials are going.  

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Hydrogen fuel cell trucks

Hydrogen fuel cell trucks are vehicles powered by electricity generated in a fuel cell using an electro-chemical reaction between hydrogen and oxygen. This electricity powers the truck's motor. Water is the only byproduct from this process.

The hydrogen is stored in tanks on the truck, and when it runs low, it can be refuelled at a hydrogen station, similar to filling up with petrol or diesel. Unlike dual fuel hydrogen trucks, which use hydrogen to partially replace diesel in an internal combustion engine (ICE), hydrogen fuel cell trucks rely entirely on hydrogen.

Hydrogen fuel cell trucks also have batteries onboard which support the fuel cell system by storing or discharging electricity. These batteries act as a power buffer to handle fluctuations in power demand to give additional power when the truck needs more energy. It also allows for the storage of electricity regenerated during braking.

The high-power output and payload capacity make them suitable for heavy-duty applications like freight, logistics, and construction. 

NZ Post project summary

Project: Hydrogen fuel cell truck and trailer

Location: Hamilton and Auckland 

Timeline: 2023-2024

Vehicle trialled: HyundaiXcient Hydrogen Fuel Cell Truck and 2-axle trailer 

Gross vehicle mass (GVM): 38,200kg 

Tare weight: 17,000kg

Battery: 72kWh

NZ Post trial results

Through the Low Emission Transport Fund (LETF), EECA provided co-funding for Hyundai NZ to bring two of its Xcient Fuel Cell trucks to New Zealand. NZ Post took ownership of one and put it straight to work in a combination of short-haul and metropolitan environments, transferring parcels across Auckland and between Auckland and Hamilton.  

NZ Post’s Hyundai hydrogen fuel cell truck trial has demonstrated that hydrogen fuel cell trucks can operate successfully in the New Zealand market, effectively replacing a diesel equivalent.

Feedback from the operators has been positive, with the truck managing to fully replace a diesel truck without losing productivity or operationality. The technology has been reliable for NZ Post, completing over 100,000km without any technical, range or refuelling issues. 

Costs and emissions reduction  

While service costs are currently similar to diesel trucks, NZ Post expects more insights into long-term maintenance costs as usage increases over the next year or two. In its first 100,000km, the truck has saved over 40,000 litres of diesel and reduced CO2 emissions by more than 110 tonnes. 

Savings achieved

  • 111.7

    tonnes of CO2 reduced per year

  • 41,667

    litres of diesel eliminated

Advantages and challenges of hydrogen fuel cell trucks

Advantages 

  • Zero tailpipe emissions – Hydrogen fuel cell trucks produce only water vapor and heat as byproducts, resulting in zero harmful emissions such as CO2, nitrogen oxides (NOx), or particulate matter (PM). 
  • Fast refuelling – It typically takes around 10-15 minutes to refuel a hydrogen truck, similar to diesel.   
  • High efficiency – Fuel cells convert hydrogen directly into electricity to power electric motors with minimal energy loss. This makes them more efficient than ICE vehicles, which lose a significant amount of energy as heat. 
  • Regenerative braking – Like battery electric trucks, fuel cell trucks use regenerative braking to recover energy into the on-board battery when slowing down, boosting efficiency. 
  • Range – Hydrogen fuel cell trucks have a range comparable to diesel trucks making them suitable for long-distance hauling. 
  • Power and torque – Like fully battery electric trucks, hydrogen fuel cell trucks deliver strong, consistent power and torque. This, paired with their strong range performance make them well-suited for heavy-duty tasks like freight transport.
  • High payload capacity – Hydrogen fuel cell trucks typically have lighter powertrain systems than battery electric trucks, allowing for higher payloads without reducing range. 

Challenges 

  • Hydrogen production and cost – While hydrogen fuel cell trucks have zero emissions, producing hydrogen can be energy-intensive and may generate emissions depending on the production method. Green hydrogen, made from renewable energy, is currently much more expensive than diesel.  
  • Hydrogen infrastructure – A key challenge for widespread use of hydrogen fuel cell trucks is the limited number of hydrogen refuelling stations, especially for long-haul routes. New Zealand currently has three hydrogen refuelling stations in key North Island hubs (Auckland, Hamilton and Palmerston North), with more planned for the future.  
  • Upfront cost – Fuel cell trucks are more expensive to produce than diesel trucks due to the costly fuel cell systems and specialised components required.  
  • Complexity and lifespan – Fuel cells rely on sensitive components like catalysts and membranes for their reactions. As a newer technology, the long-term durability and maintenance needs of fuel cells are still uncertain and may vary based on fuel quality and operating conditions. 

Over time we'll better understand the long-term service requirements and get a clearer TCO. As others invest in hydrogen trucks, we’d expect to see lower capital and lower hydrogen costs from market maturity.

Ryan Beale, National Road Operations Manager, NZ Post

Dual fuel hydrogen trucks 

Dual fuel hydrogen trucks use diesel engines modified with an additional fuel injection system to inject hydrogen alongside diesel.  

Hydrogen is stored in high-pressure tanks on the truck, usually behind the cabin. These tanks are typically made of lightweight, strong materials such as carbon fibre and aluminium to handle the pressures needed for hydrogen storage. 

The hydrogen is injected into the engine's air intake system or directly into the cylinder, depending on the design. It combusts alongside the diesel, lowering the vehicle's overall diesel consumption and, consequently, reducing its diesel emissions. 

Diesel trucks can be converted to partially run on hydrogen, allowing companies to adopt cleaner technologies gradually, balancing risks with environmental benefits. 

Modifications and impact 

The main modifications to the trucks are the addition of the hydrogen injection system to the engine and five hydrogen tanks, which together hold about 23kg of hydrogen. The system, including full tanks and covers, weighs 960kg. This added weight does not typically impact payload, however may slightly reduce payload capacity in some trucks, but depending on the application this may not be an issue.

HW Richardson project summary

Project: Hydrogen dual fuel trucks 

Location: Invercargill and Taupo  

Timeline: 2023-2024 

Vehicles trialled: Various conversions 

 

HW Richardson trial results

To date, HW Richardson has converted a range of trucks to dual fuel, including a DAF milk tanker, a Volvo milk tanker, a Volvo freight truck, two DAF bulk haulage trucks, and a Mack concrete truck.

Six conversions have been supported with co-funding from EECA’s Low Emission Transport Fund. HW Richardson is fully funding the conversion of a further four trucks for its internal businesses, while commercialising the product for transporters interested in converting to dual fuel.

The trial has found performance of the dual fuel hydrogen trucks to be comparable to diesel trucks. The trucks have been assessed using trials on hilly sections of state highway one in New Zealand, to confirm the diesel displacement, and the resulting carbon emission reductions.

The hydrogen tank capacity is designed to align to the daily use requirements of the truck, and minimising any payload impact so both fuels are used at a similar rate and refuelling can be synchronised. It takes around 7 minutes to fill the system with hydrogen.  

Cost and emissions reduction 

Converting a truck to dual fuel costs $150,000 for the hydrogen kit, plus an annual lease of $20,000 over six years. This matches many operators' vehicle turnover timelines. The installation, maintenance, fairings and covers are additional costs. 

By burning hydrogen alongside diesel, HW Richardson says that the truck can consume approximately 30% less diesel. As hydrogen combustion has no CO2 emissions, this fuel reduction translates to a 30% CO2 reduction in tail-pipe emissions. This means that a truck running 380km per day can cut carbon emissions by 200kg daily, or around 70 tonnes per year, without losing productivity. 

Savings achieved

  • 30 %

    Reduction in vehicle emissions

  • 70

    tonnes of CO2 reduced per year, per truck

Advantages and challenges of dual fuel trucks

Advantages 

  • Lower upfront cost – Converting an existing diesel truck to a dual fuel system involves modifying the engine to allow hydrogen injection alongside diesel, rather than completely replacing the powertrain or buying a new vehicle. This makes it more affordable for fleet operators to switch to cleaner fuel options. 
  • Reduced tail-pipe emissions – Partially substituting hydrogen for diesel lowers harmful emissions like carbon dioxide (CO₂), nitrogen oxides (NOₓ), and particulate matter (PM). 
  • Lower hydrogen infrastructure dependency – Dual fuel trucks are not entirely dependent on hydrogen, lessening the risk of a lack of access to fuel in a transitioning market.    
  • Enables gradual transition – These trucks offer a transitionary step towards cleaner technologies, allowing transport businesses to trial using hydrogen before fully committing to fuel cell technology. 
  • Ability to convert large trucks – Dual fuel trucks allow for conversion of all trucks including trucks greater than 40 tonnes. Other options to decarbonise in this size vehicle are currently more limited. 

Challenges  

  • Payload impact – Like other hydrogen vehicles, dual fuel trucks need high-pressure hydrogen tanks, which take up space and add weight, potentially reducing the truck's payload capacity. However, the impact on payload is less than that of battery electric vehicles. 
  • Hydrogen cost – Hydrogen is currently more expensive than diesel. Production of green hydrogen is costly due to the energy-intensive electrolysis process and the cost of electricity. As hydrogen production and distribution scale up, prices are expected to decrease. In the short term, fuel costs remain a key consideration for dual fuel hydrogen truck adoption. Hydrogen from other sources generally has overall emissions comparable to, or worse than, diesel.  
  • Partial emissions reduction – Dual fuel trucks can only replace a portion of diesel with hydrogen due to combustion limits, so they cannot reduce emissions as much as hydrogen fuel cell or battery electric trucks. 
  • Resource efficiency – Burning hydrogen in a diesel engine is less efficient than using it in a fuel cell. As green hydrogen production remains limited, widespread use of dual fuel trucks could compete for this resource, hindering the adoption of more efficient fuel cell trucks. 
Hiringa hydrogen refuelling station at Waitomo Te Rapa, Hamilton.
Hiringa hydrogen refuelling station at Waitomo Te Rapa, Hamilton

Expanding the hydrogen refuelling network 

Enabling hydrogen powered transport will take new infrastructure to fuel these vehicles. HW Richardson plans to expand the hydrogen refuelling network through its company, Allied Petroleum. Their first green hydrogen production facility is being developed in Southland, aiming to produce 450kg of hydrogen per day. 

Hiringa Energy is another business devoted to the supply and distribution of green hydrogen in New Zealand. With support from the Covid Response and Recovery Fund, they have opened fuelling stations in Auckland, Hamilton and Palmerston North, with one in Tauranga under construction.  

These strategic locations cover more than 95% of the North Island's heavy freight volume (tonne-km), making hydrogen-powered trucks a more feasible prospect for transport companies. 

Hiringa makes the hydrogen onsite by using electricity to split water into hydrogen and oxygen through a process called electrolysis. The hydrogen is then compressed and stored, ready to refuel vehicles at high pressure, allowing trucks to get a full tank in less than 20 minutes. 

Funding available for zero and low-emissions trucks

Grants from EECA’s Low Emissions Heavy Vehicle Fund (LEHVF) will cover up to 25% of the purchase price of new zero-emissions heavy vehicles, or up to 25% of the cost to convert an existing, recently registered, diesel truck to hydrogen dual fuel or plug-in diesel-electric hybrid technology. 

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