Hexagon Bullish on CNG for Long-Haul Trucks

May 29, 2024

Matt Wolfe

Though some OEMs have signaled that the end of the ICE age is nigh, reports of the combustion engine’s death as the backbone of the commercial-trucking industry are greatly exaggerated. Battery-electric vehicles are seeing continued growth in various medium-duty and last-mile delivery sectors, but their lack of energy density and cost per have prevented them from gaining market share for Class 6 and larger commercial vehicles in North America.

Several suppliers are anticipating that this trend will persist over the coming decades and are making major investments in the development of alternative fuel systems for diesel combustion engines. One such supplier is Hexagon Agility. Based in the northern suburbs of Charlotte, North Carolina, Hexagon recently announced expansion plans of its Salisbury, North Carolina facility to field orders and installations of its compressed natural gas (CNG) fuel systems.

SAE Media was invited to tour the facility and interview several of Hexagon’s engineers and executives about the future of the company’s growth, the business case for CNG fuel systems and why the company feels that this technology is worth investing in despite the development and proliferation of BEV powertrains for commercial vehicles of all sizes

One of the developments that Hexagon is hanging its hat on is the release of the new Cummins X15N engine, which is compatible with CNG fuel systems. According to Hexagon, this engine represents a watershed moment for CNG system suppliers as the engine’s capacity and output enables their systems to serve markets that were preciously unreachable.

“The launch of the Cummins X15N 15-liter engine will triple the addressable market for heavy-duty natural-gas trucks over the next few years,” said Eric Bippus, EVP sales and systems for Hexagon Agility. “This is a game-changer for our niche industry, enabling a powerhouse solution for Class 8 fleets traveling locally and cross country.”

Hexagon confirmed via a press release that the company is taking orders for CNG fuel system installations on pilot trucks powered by Cummins’ new X15N engine. According to the release, these orders came from “major fleets and cover two leading original equipment manufacturers.” In February of this year, Kenworth became the first to open its order books for trucks powered by the Cummins X15N engine.

The X15N is an inline-six-cylinder configuration with ratings of 400 to 500 hp (298 to 373 kW) and 1,450 to 1,850 lb-ft (1,966 to 2,508 Nm) of torque with a max engine speed of 1,900 rpm. Cummins states that the X15N meets EPA and CARB regulations in 2024 and 2027 thanks in part to a passive and maintenance-free three-way catalyst aftertreatment system. Cummins also claims that the X15N demonstrates up to a 10% improvement in fuel economy compared to the current ISX12N.

Bippus detailed the impact that the introduction of the Cummins X15N will have on the CNG truck market. “The big thing with the 15-liter is that today’s natural gas engine stops at 400 horsepower,” he said. “Most of your heavy-duty fleet usually need 430-plus [horsepower]. Telling the heavy-duty sector they need to downgrade on horsepower isn’t going to go over well. The 15-liter solves for all of this.”

Bippus continued: “When you have 450 to 500 horsepower you pick up efficiency because you’re not pushing that engine nearly as hard and the heavier applications can run in the sweet spot for torque. The 15-liter really expands the natural gas market. The 12-liter does a good job in regional-haul applications that don’t need the range or the weight capacity of the larger trucks, but the 15-liter will enable us to cover the entirety of the market.”

The big picture

CNG systems have been a mainstay of fleets globally for decades, but the U.S. currently has the largest market share for these systems. “North America is still our biggest market,” said Hans Peter Havdal, group COO and CEO for Hexagon Agility. “Last year, our systems removed over 1.5 million metric tons of CO2 emissions that would have come from diesel engines. This is a trend that we need to help continue to grow in order to meet the challenge of decarbonization.”

“Many OEMs and governments around the world have aggressive targets for emissions reductions by 2030,” Bippus said, “which means we look at technology like natural gas. If you really want to hit those targets we have to deploy at scale. Small science projects of five to ten deployments don’t work – we need hundreds and thousands of vehicles going to the market every year.”

Bippus explained the current market position of renewable natural gas (RNG) trucks in North America. “The U.S. has actually done a great job with making renewable natural gas/biomethane accessible for fleets,” he said. “Ninety-eight percent of CNG vehicles in California run on renewable natural gas and around 64% of CNG [vehicles] nationwide are running on renewable fuel. When we talk about the negative-emissions capability of RNG, you have to look at the full picture. Electricity and hydrogen still have an environmental impact because much of the U.S. electrical grid is still coal-fired. So, you do have emissions from those propulsion systems.”

Bippus continued: “When you look at the vehicle space, based on CARB data, biomethane has a score of negative 99 grams per megajoule used versus diesel. That translates to about a 200% improvement. Our market position is that if you look at the energy density needed to support heavy transportation, it’s got to be sustainable. If it indefinitely needs to be government-funded there’s a challenge.”

Bippus also explained the use case for RNG as a fuel for the long-haul heavy-duty industry which, in Hexagon’s view, provides a ready solution for large-scale decarbonization. “When you look at the methane molecule compared to all the molecules that are out there as energy sources today, its abundance and energy density is far and away one of the best options for heavy-duty transport,” he said.

“A typical heavy-duty truck will see around 100,000 miles (160,000 km) per year and be used almost every day,” Bippus added. “A BEV truck with a 750-kWh battery can get about 250 miles (400 km) if you’re in an aggressive environment with hills or extreme payload. A compressed hydrogen truck at 700 bar (10,000 psi) can get about 450 miles (750 km). With a CNG system, you can easily get 750 miles (1,200 km).

“When we look at the future, there’s multi-technology solutions for every sector,” he continued. “But when we look at the energy needed for high-payload and longer range, this is a solution that is available now and can be deployed at scale.”

Hexagon Agility is expanding capacity for its fuel systems as more fleets are expected to “make the switch” to CNG/RNG. Production start for its new line is set for the first quarter of 2025, to coincide with the increased market demand.

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