Partnering to Produce Fuel-Cell-Electric Trucks

Plug Power and Lightning Systems are working to introduce the world’s first Class 6 FCEV in the third quarter of 2020.

May 13, 2020

Kami Buchholz

Plug Power and Lightning Systems have partnered to build zero-emission hydrogen fuel cell-powered Class 6 electric trucks. (Lightning Systems)

A first-of-its-kind propulsion alternative for transporting products between ports, warehouses and distribution centers is on the horizon. “The Class 6 fuel-cell-electric vehicle (FCEV) is a perfect zero-emission solution for the movement of goods through the ‘middle miles,’” said Andy Marsh, CEO of Plug Power Inc., a supplier of hydrogen fuel-cell systems. Plug Power and electric drivetrain manufacturer Lightning Systems recently partnered to produce what they claim is the world’s first hydrogen fuel-cell-powered electric Class 6 truck.

A separate electric motor (shown) is situated in the accessories sled, where the diesel engine would be in a conventionally powered Class 6 truck. This electric motor powers many of the important subsystems, including air compressor for the brakes, the power steering pump, the cabin A/C compressor and the coolant pump for the battery’s active thermal-management system. (Lightning Systems)

Built off the Chevrolet Low Cab Forward 6500XD platform, the standard FCEV has an estimated driving range of 200 miles (322 km). An extended-range option doubles the range to 400 miles (644 km). “The most important benefit of a fuel cell-equipped BEV is operating range,” said Tim Reeser, CEO of Lightning Systems. “Many intermodal delivery routes in the United States are greater than 150 miles, making the fuel cell-equipped BEV an ideal piece of equipment for the ‘middle mile’ vocation.”

From a hardware perspective, the extended-range version adds a second hydrogen storage tank and associated control valve. “The tank – or tanks, depending on the configuration – is identical to the storage tank/s used to provide the initial range,” said Bill Kelley, chief technology officer (CTO) and chief operating officer (COO) of Lightning Systems.

The FCEV’s two battery packs complement the fuel-cell system by storing charge and by providing additional current for higher-power demand. (Lightning Systems)

The SAE J1772 CCS-1 combo changing port provides Level 1 and Level 2 charging. The Li-ion NMC batteries alone provide an expected range of 40 miles, which is useful when needing to evacuate the hydrogen system or for servicing purposes. (Lightning Systems)

The Class 6 FCEV will be powered by a 90-kW fuel-cell system comprised of three 30-kW modules running in parallel. “Each module is a complete, self-contained power unit that includes stack, air delivery, cooling system and DC/DC converter in the box,” explained Keith Schmid, COO of Plug Power. The metal stack’s innovative membrane electrode assembly (MEA) is crucial to the fuel-cell system’s functionality. “Through our R&D activities, we developed an ink catalyst and material formula for our MEA technology that improves efficiency and enhances durability,” said Schmid.

Plug Power began manufacturing MEAs in the third quarter of 2018 from its Rochester, New York, facility, following the acquisition of American Fuel Cell. “We’re leveraging existing expertise and infrastructure in fuel-cell technology as well as thin-film coating and roll-to-roll manufacturing,” Schmid noted. To date, more than 30,000 Plug Power fuel cell systems have recorded more than 300 million operating hours in the material-handling industry.

Transitioning to FCEVs

Material-handling applications paved a path for Plug Power’s transition to the logistics delivery market. “We designed our systems to be heavy enough to meet the minimum weight required to replace a lead-acid battery in a forklift – where it was used as a counterbalance – to the FCEV on-road market, where making the fuel-cell system lighter is important to benefit vehicle efficiency and payload capacity,” Schmid said.

Reducing the weight of the fuel-cell system spotlights lightweight material usage, a thinner metal fuel stack plate and next-generation MEA technology. “This has allowed us to achieve a much higher power density than previous-generation fuel-cell stacks,” said Schmid.

The fuel-cell truck’s EV drivetrain is comprised of a 220-kW electric motor and a 2-speed (3.53:1 and 1:1) gearbox. “The typical BEV version of a Class 6 vehicle uses 160 to 192 kWh of high-voltage batteries, resulting in about 100 to 200 miles of operating range,” said Kelley. The Class 6 FCEV truck uses 64-kWh lithium-ion nickel manganese cobalt oxide (Li-ion NMC) batteries, stored in two packs that are cooled by an active thermal-management system.

Seen from below, the 220-kW motor provides propulsion through a 2-speed transmission to the main driveshaft to the rear axle. The power inverter can be seen at the bottom left of the image. (Lightning Systems)

Installed where a conventional engine and transmission would be located, the electric drivetrain uses the original-equipment driveshaft. The 2700 cells in each battery pack and the packaging of other FCEV-related hardware does not interfere with typical aftermarket equipment such as liftgates and boxes.

Ready for the road

Since 2018, the EV platform has undergone lab and road testing. Fuel cell modules are subjected to typical load profiles to ensure that performance meets the specifications. “The hydrogen-storage modules are also pressure-tested to make sure they are 100% leak-free and ready for service,” said Marsh.

Final production testing of each Class 6 FCEV, including at least 200 miles of on-road evaluations, will be completed before delivery to customers. Plug Power and Lightning Systems’ FCEV trucks will be commercially available in the third quarter of 2020.