Whereas battery autos usually seize the headlines, the inner combustion engine remains to be a significant a part of the vitality transition within the off-highway sector, with environment friendly diesel, dual-fuel, hydrogen combustion and hybrid options being developed
As the development and mining industries search to cut back their carbon footprint, producers are creating modern engine applied sciences that preserve energy and reliability whereas chopping emissions. From dual-fuel hydrogen options to full hydrogen combustion engines, these developments are accelerating the transition to zero-emissions in off-highway functions.
Volvo Penta and CMB are collaborating on a dual-fuel hydrogen resolution for each land and marine functions. This partnership builds on profitable pilot initiatives courting again to 2017, throughout which Volvo Penta engines have been tailored to run on each hydrogen and diesel utilizing CMB expertise.
The brand new collaboration leverages Volvo Penta’s established Stage V D8 engine platform, enhanced with CMB’s hydrogen injection system. Hydrogen is launched from storage tanks, dropped at low strain, and injected into the engine’s air consumption. This reduces the quantity of diesel required to supply the identical vitality output, lowering CO2 emissions whereas sustaining efficiency. “The entire Volvo Group is working intensively to discover options to cut back, and in the end remove, greenhouse gasoline emissions,” says Heléne Mellquist, president of Volvo Penta. “We’re teaming up with suppliers, companions, and clients to speed up the journey into fossil-free fuels for each on land and at sea functions.”
A bonus of the dual-fuel resolution is its fallback functionality. If hydrogen shouldn’t be accessible, the applying can proceed operating on conventional gasoline. This makes it significantly appropriate as a transitional expertise whereas hydrogen infrastructure develops. “This can be a resolution the place you utilize hydrogen and diesel together,” says Ann Parmar, VP advertising and marketing at Volvo Penta. “It’s not the total hydrogen engine, the place it is advisable construct it from scratch.”

“From the preliminary dual-fuel expertise initiatives we have now seen reductions of CO2 emissions as much as 80%” says Roy Campe, CTO of CMB. “It’s clear that the vitality transition is a significant problem in lots of sorts of functions. With the dual-fuel expertise we have now been creating over the previous few years, we are able to present an economical and strong resolution for a wide range of functions.”
Full hydrogen combustion
Whereas Volvo Penta focuses on dual-fuel expertise, JCB is taking a special strategy with its £100 million funding in absolutely hydrogen-powered combustion engines. After three years of growth by a crew of 150 engineers, JCB just lately introduced the official certification for its engine for business use in 11 European international locations. “It’s a vital second for JCB,” says JCB chairman Lord Bamford. “To begin 2025 with certification in place in so many European international locations bodes very effectively for the way forward for hydrogen combustion expertise. JCB has proved lately that it’s a correct zero emissions resolution for a variety of development and agricultural autos.”
JCB has already produced over 130 analysis engines powering backhoe loaders, Loadall telescopic handlers and generator units. Furthermore, 2024 noticed over 50,000 hours of hydrogen engine testing. JCB additionally accomplished greater than 25,000 km of on-road testing on the request of the UK Authorities to reveal that hydrogen-powered machines are secure to be used on British roads.
“5 years in the past, hydrogen combustion engine expertise was not even on the radar, and now it’s being permitted and endorsed by governments. That is actually outstanding, however it is just the start,” says JCB’s group director for particular initiatives, Tim Burnhope.
Pathways to sustainability
Liebherr is pursuing a number of avenues for lowering emissions in off-highway functions together with an expanded diesel engine portfolio, superior hydrogen engine growth, and analysis into ammonia in its place gasoline.
At Bauma 2025, Liebherr unveiled its new D9612 diesel engine, delivering a most energy output of 950kW for demanding off-road functions, significantly specializing in agricultural equipment. The corporate additionally showcased modern expertise like its hydraulic air boosting system which improves engine dynamics and effectivity. “In our machines, we transmit energy utilizing pressurised hydraulic fluid,” says Bouzid Seba, head of pre-development at Liebherr Machines Bulle. “Sure actions require the discharge of strain, which leads to vitality loss. Our innovation doesn’t solely permit to recuperate and retailer this vitality, but in addition to make use of it subsequently on demand in our hydraulic air booster. When wanted, the air booster pushes giant portions of air into the motor to assist it ship energy shortly,.
Liebherr’s parts product phase has additionally invested considerably in hydrogen engine growth and testing amenities. Since 2020, prototype engines have undergone rigorous testing, and the corporate is at present evaluating completely different injection and combustion applied sciences. This consists of port gasoline injection (PFI) and direct injection (DI).
To future-proof its portfolio additional, Liebherr showcased an idea ammonia engine at Bauma 2025. Inexperienced ammonia serves as a hydrogen service, providing decreased transportation and storage prices. The corporate means that turbines and off-highway powertrains fuelled by inexperienced ammonia may present low- or zero-emission options, significantly for mining.
Hybrid energy enlargement
Caterpillar Industrial Energy Methods is advancing its electrification technique with the introduction of its Collection Hybrid Energy Growth powertrain, combining diesel-electric and battery expertise to optimise energy effectivity and scale back emissions.
Additionally launched at Bauma, the brand new powertrain operates by way of an built-in system the place a Cat engine drives a generator to transform mechanical vitality into electrical energy. An inverter then manages energy distribution from each the generator and battery to the electrical motors that drive the machine. This setup permits the battery to retailer unused vitality for peak energy calls for, enhancing system effectivity.
“This is a perfect resolution to satisfy the present wants of lots of our clients,” says Steve Ferguson, senior vp of Caterpillar Industrial Energy Methods. “Combining the engine and battery supplies greater energy functionality than utilizing both an engine or battery alone. This permits for management optimisation to distribute energy from a number of sources, maximising powertrain effectivity. Clients profit significantly from decreased downtime, improved gasoline effectivity, and lowered restore frequency, minimising the entire price of possession.”
The hybrid powertrain system consists of 5 key parts working in concord. The engine serves as the first energy supply, offering mechanical energy to the generator. This technique is designed to be appropriate with engines throughout the Caterpillar vary, together with future developments operating on various fuels. The generator is intently coupled to the engine and chosen to align with engine capabilities to offer electrical energy.
On the coronary heart of the system is the inverter, the central element that manages vitality from the generator or battery and distributes it to the motors. It may well additionally settle for recuperated vitality from the motors to recharge the battery. The motor converts electrical output from the inverter into the required torque and pace. Moreover, the motors are able to absorbing mechanical vitality and rework it into electrical output for braking and regeneration.
Finishing the system is the battery, which shops extra vitality from the engine or regenerative vitality from the motors, offering speedy energy response to satisfy important cycle necessities. It may well complement engine energy or act as the only energy supply when wanted.
The hybrid functionality permits for zero-exhaust emissions when operating on battery energy. Moreover, with applicable gear, the Collection Hybrid Energy Growth powertrain can perform as a cell energy supply with export functionality.
Past hybrid expertise, Caterpillar is actively creating hydrogen options for its engines. A crew of engineers is testing numerous various fuels, together with hydrogen, methane, methanol and ethanol. “We’re doing this work now. This implies when our clients are prepared to maneuver to hydrogen or different fuels, we will present them with our deep experience and studying to make sure a easy adoption,” says Luke Bennett, Caterpillar product specialist.
At Bauma, Caterpillar demonstrated its hydrogen growth progress by way of a simulated take a look at cell atmosphere for the C18, a gasoline engine transformed to run on hydrogen.
“We’ve been working it on high and low ambient temperatures and looking out on the vibration results of the engine, which is how we examine various fuels within the evolving vitality panorama. We’re utilizing what we’ve realized from this expertise for our different engines in growth,” says Bennett.
A greener future
It’s clear that whether or not by way of enhancing the effectivity of diesel combustion, implementing various gasoline options or combining electrical energy in hybrid powertrains, the inner combustion engine nonetheless has an important position to play within the drive to decarbonise off-highway.
The event of those applied sciences highlights how completely different approaches might be taken to reaching the identical purpose: lowering emissions whereas sustaining efficiency and reliability. What unites them is the popularity that the trade wants sensible, dependable options that may be applied within the real-world, as Burnhope highlights: “It’s not nearly what’s written on paper; it’s about actual machines engaged on actual job websites, making an actual distinction to the trade.”
This text first appeared within the June concern of iVT