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In addition to battery-powered electric motors, construction equipment OEMs and engine manufacturers are also racing to develop new engine technologies that use hydrogen as a fuel. So far, hydrogen internal combustion engines (ICEs) have shown promise, with several companies (including JCB, Perkins, and Cummins) announcing plans to produce dedicated H2 or fuel-agnostic ICE engines. However, debate continues over whether another form of hydrogen—hydrogen fuel cells—is suitable for off-highway applications. Fuel cells involve pumping compressed hydrogen from a carbon fiber-reinforced fuel tank into a fuel cell stack, which combines oxygen and hydrogen to generate electricity for the electric motor rather than burning it. As the industry continues on its path to decarbonization, their potential inclusion in future construction equipment remains a question.

This was illustrated at the recent Diesel Progress Summit in Louisville, USA (organized by KHL's Diesel Progress magazine), where representatives from electric power solutions company Volvo Penta and British construction equipment manufacturer JCB presented differing perspectives on the matter. Chris Giorgianni, vice president of product for JCB North America, told attendees during a roundtable discussion that the company is committed to developing machines with electric motors and hydrogen combustion engines, but has ruled out fuel cells.

JCB is one of several engine manufacturers preparing to bring hydrogen engines to market as early as next year. "We do see the value in electricity, namely zero emissions and low noise," he says. "But there are drawbacks. They are very expensive, with some units costing almost twice as much as diesel units." Giorgianni says these factors led JCB to research fuel cells and build some of its large excavators. While the company has found that these machines don't necessarily produce lower noise levels, they have "better noise quality," can be refueled quickly, and have low emissions. The main drawbacks are cost, and hydrogen fuel cells require a special coolant that can easily be mixed up with other coolants if machines with different engine types are used at the same site.

"From a fuel cell perspective, we did feel that while the technology was great, we didn't feel it was practical in our environment," Giorgianni concluded. JCB has instead focused its efforts on hydrogen combustion engines. The company's hydrogen combustion engines already power prototype backhoe loaders and Loadall telehandlers, and the company recently launched a mobile fueling station that it designed and built.

Giorgianni's comments contrasted with those of Darren Tasker, Volvo Penta's Vice President of Industrial Sales for the Americas, another speaker at the Diesel Progress Summit. Tasker stated that Volvo Penta anticipates a variety of technologies powering future engines. Regarding hydrogen, he said, "It's clearly going to be a powerful technology in the future. Today we have a hydrogen-diesel dual-fuel engine. In 18 months to two years, we'll be launching a natural gas engine, which is part of the evolution of hydrogen technology. That natural gas engine will be full spark ignition, and the next step will be to have a 100% hydrogen spark engine family. Of course, we're not just working on the technical aspects of hydrogen for off-highway and power generation applications; we're also looking at how to effectively partner with hydrogen suppliers to deliver green hydrogen that aligns with our 2050 goals. So, it's a technology development path, but also a fuel availability development path, and I think that's a path that not only Volvo but many of the supply chain powertrain suppliers are on." Given the debate surrounding the topic, when asked if he believed fuel cells were suitable for off-highway applications, Tasker said, "We think the fuel cells we're developing are powerful enough for off-highway applications. They can be a standalone fuel source, but they're more effective when used in conjunction with batteries."

However, Tasker acknowledged that there's still work to do in helping customers navigate the high capital costs associated with new forms of technology. He added, "As a powertrain supplier, we need to help our customers successfully transition. We know this technology comes with high tariffs. It's expensive, and it requires a lot of R&D to develop." "Early adopters will face the question of how do we commercialize this? There, we'll have to consider different business models. How do we charge for energy as a service rather than hardware? How do we look at leasing options? How do we look at tariffs that reduce usage and put the energy into operation, while offsetting the costs over time with lower operating costs?"

Speaking at the summit, Jim Nebergall, general manager of Cummins Hydrogen Engines, said the company is pursuing both types of technology. "We don't really think of it as a fuel cell or an engine. They're very complementary. Filling the device is the same as a fuel cell or an engine. The production and distribution of the fuel can be complementary. It's rare to have two technologies that are so different—engines and fuel cells—that can use the same fuel. So having both options will help build the infrastructure and drive demand."

Paul Mercurio, U.S. sales manager for Liebherr Fuel Injection Systems, also said he expects fuel cells to be "part of the mix." Mercurio said this is particularly true for larger machines, where Liebherr still sees a need for internal combustion engines fueled by diesel, biodiesel, and hydrogen. He added that there are also challenging applications such as mining trucks, large earthmoving projects, and bulldozers that operate under extreme conditions where "battery power may not be able to reach the full potential that is needed." "At the same time, there are applications for fuel cells," he added. "There are some concerns about fuel cells because the hydrogen used in fuel cells has to be very pure, and on a job site like this, hydrogen is very dirty and dusty. That's something that needs to be considered when refueling in the field, as well as keeping the fuel cells clean so that they can operate properly."

Kohler Engine Company has unveiled its new KDH direct-injection hydrogen-powered internal combustion engine. The launch of this new product, expected to begin accepting orders in 2026, builds on the news earlier this year that Kohler Energy will be established as an independent company.

The hydrogen engine is based on a derivative of Kohler's KDI 2504 TCR engine, which utilizes a traditional internal combustion engine architecture but replaces diesel with hydrogen. Environmentally, hydrogen engines burn cleaner than standard diesel engines. Kohler states that the KDH is designed to be a direct replacement for diesel models. OEMs can expect compatibility with existing machine platforms, as the engine platform will retain the same cooling circuits, power take-offs and flywheels, engine mounting points, and intake lines. The KDH and KDI models share several components, with only the fuel lines requiring adjustments due to the switch from diesel to hydrogen. Because the hydrogen option fits within the current engine housing size of Kohler's compact diesel engines, no major modifications to the engine compartment are required. The use of direct injection rather than port fuel injection avoids any backfire issues, allowing the new engine to maintain diesel-level performance, including transient response. Kohler states that the KDH engine is designed to match the performance of the diesel model in terms of maximum power, peak and low-end torque, as well as transient response and drivability. Kohler says the potential environmental benefits of hydrogen use are further amplified when an aftertreatment system (ATS) is applied to a hydrogen internal combustion engine, due to the additional reduction in exhaust emissions. Adding the ATS reduces tailpipe particulate matter (PM), nitrogen oxides (NOx), and hydrocarbons (HC) to negligible levels, making the engine near zero emissions by most definitions. "We look forward to launching this evolving technology and working closely with our partners to drive innovation, sustainability, and decarbonization in the industry," said Vincenzo Perrone, President of Kohler Engines.

Source: Foreign publications