Dual Fuel in action

HWR plans to lead the heavy transport industry’s transition to hydrogen through dual-fuel, where trucks run on both hydrogen and an existing fuel source.

The dual-fuel system involves retrofitting the hydrogen system to an existing diesel combustion engine. The hydrogen used to fuel the truck is stored as a gas in tanks on a frame behind the cab of the truck. The tanks can hold 5kg of hydrogen each, and most truck configurations will hold 5 tanks (equating to 25kg of hydrogen). The additional weight added to the truck from the conversion utilises spare tare weight if available and aims to optimise payload where possible.

Hydrogen is injected during the engine’s intake stroke and mixed to be uniform and homogeneous during the compression stroke. Diesel is used as the pilot fuel, and the diesel auto-ignites and co-combusts with the hydrogen, forcing the piston down during the power stroke. The control system for the truck ensures the energy requirement to the engine remains the same whether fuel is coming from hydrogen and diesel, or just diesel. Trucks fitted with HWR Hydrogen’s dual-fuel system will reduce up to 40% of carbon emissions in dual-fuel mode without compromising existing operations, routes, distances, or payload.

The entire hydrogen system has been built with safety as the priority. The system, tanks, and frame have been designed and modelled to meet stringent European hydrogen standards. It is designed with fail-safe sensors and shut offs that operate electronically and mechanically, meaning there are three layers of protection.

HWR Hydrogen have a fleet of dual fuel trucks on the road to test the performance and efficiency of dual-fuel of the technology.

“Blue Hydro” in the Dynes fleet, was the first of these. The trial will confirm the displacement values for hydrogen over diesel, the effectiveness on New Zealand roads, and the ability to perform with our payloads. To fuel the trucks, we are commissioning a hydrogen station in Southland.

Preliminary results suggest dual-fuel is a solid option that works. Since our initial tests and having Blue Hydro on the road, there has not been any drop in power or significant downsides. Additional dual-fuel trucks will be inserted across HWR’s companies to test their performance across different driving and load disciplines.

A significant benefit of the dual-fuel truck is that while the hydrogen infrastructure is being developed in New Zealand, our dual-fuel trucks can operate on 100% diesel when there is no hydrogen available. We believe these trucks are the key intermediary step to the 100% hydrogen vehicles which are being developed throughout the world. Without this step New Zealand will not have the infrastructure to move to full hydrogen vehicles when they become available. As dual-fuel trucks go through their lifetime, they will eventually end up in the fleets of smaller operators who would otherwise be blocked from the hydrogen network through prohibitive cost. As the industry moves towards hydrogen as its fuel source, dual fuel trucks will mean the entire industry – down to small businesses – will be on the sustainability journey.