Fuel-cell electric vehicles (FCEVs) are a highway rarity despite decades of technology development. “When I was working in Europe 20 years ago, I was driving fuel-cell prototype cars. They were very, very good, but they didn’t make it to serial production,” said Michael Lohscheller, president and CEO of Nikola Corp., a startup company focused on zero-emission commercial vehicles and energy solutions. “Sometimes,” Lohscheller emphasized, “the timing has to be right for innovation.” Nikola’s time for innovation that leads to serial production is now.
In the second half of 2023, Nikola expects to begin commercial production of a hydrogen-fueled electric cabover truck, marking an industry-first for the North American market. Nikola’s FCEV is a follow-up to the company’s Tre BEV, a zero-emission Class 8 semi-truck. “We produced our first 258 electric trucks in 2022, and those trucks are going to dealers and customers,” Lohscheller said in a recent interview with SAE Media in Detroit.
From clean sheet to production
The Tre BEV went from clean-sheet design to production in less than three years. Its propulsion, thermal, electrical (low-voltage and high-voltage), controls, electronic control unit hardware and certain chassis and cab components were developed from the ground up for efficiency and performance optimization. The cab-in-white, a carryover from Iveco’s S-way, is made from a combination of mild-strength and high-strength steel. Modifications were made to the chassis and cab design to meet North American market requirements and align with Nikola’s design standards, according to Kyle Ness, global chief engineer for Nikola’s BEV.
Operating on an 800-volt system, the BEV provides a continuous 645 hp (480 kW). Its total onboard energy capacity is 733 kWh, stored in nine battery packs connected in parallel. The lithium-nickel-manganese-cobalt-oxide (LiNiMnCoO2) cylindrical cells, according to Nikola officials, deliver a driving range of up to 330 miles (531 km) when the truck is loaded.
“The architecture of the high-voltage system provides a unique capability of operational redundancy. Batteries are electrically and thermally connected in strings of three (fore/aft in vehicle direction), which allows the vehicle to operate on six battery packs if required,” Ness noted. Cypress, California-based Romeo Power, acquired by Nikola in 2022, is the battery supplier.
Several patents and pending patents address various vehicle systems, including the thermal-management system, power controls, high-voltage battery, battery-frame assembly and electric axle, which is being supplied by FPT Industrial. Nikola also has intellectual property rights for different vehicle functions, including the battery- management system, HMI/infotainment and software.
“We write our own software in-house, not only for infotainment but also for the entire drive-by-wire architecture,” Lohscheller said. Nikola has more than 120 suppliers for its Tre BEV and Tre FCEV. “Everybody is talking about supply-chain difficulties. Nothing is easy these days, but we manage very well,” he added.
SAE Media recently took a short ride on Detroit city streets inside a pre-production Nikola BEV with driver Adam Tarleton, Nikola’s head of vehicle validation. “We accumulated more than a half-million testing/validation miles while hauling loads in specific applications. It took us about 14 months,” he said, referencing activities with Nikola’s 40-truck test fleet and customer demonstration vehicles. On-road testing occurred in Michigan’s upper peninsula during cold weather, as well as year-round in Arizona with customer support in California and a few other states.
“We learn something every day, so having a pioneering mindset is important,” Lohscheller stressed.
Engineering the fuel-cell truck
Innovative thinking worked well for the development of Nikola’s BEV as well as the company’s soon-to-market FCEV. Nikola has several patents and pending patents addressing the FCEV, including the thermal-management system, hydrogen fueling and diagnostics, hydrogen fuel storage and the air management for the fuel-cell power module.
Nikola’s FCEV has five 700-bar (10,150-psi) hydrogen tanks for a total of 70 kg (154 lbs.) of usable hydrogen. The net power output is up to 200 kW (268 hp). For engineers, designing and integrating the truck’s thermal system was not a simple task. That’s because there is limited real estate for radiators and a fuel cell typically rejects more heat than does a diesel engine.
A fuel cell also operates at slightly lower temperatures, according to Christian Appel, global chief engineer for the fuel cell truck. “Nikola overcame this engineering challenge with a sophisticated thermal-system design that combines multiple dedicated cooling loops depending on the operating mode,” he said.
With a range of up to 500 miles (805 km), Nikola’s Tre FCEV has an estimated refueling time of approximately 20 minutes. In early 2023, Nikola celebrated the first 100 orders for its fuel-cell truck. Complementing that milestone was Nikola’s January 2023 announcement of its HYLA (first two letters of hydrogen, last two letters of Nikola) brand.
According to Carey Mendes, president of Nikola Energy, the company anticipates having 60 HYLA hydrogen refueling stations in the U.S. and Canada by 2026. Those refueling stations would supply 300 tons of hydrogen daily, which translates to roughly 7,500 fuel-cell trucks a day.
Mendes said that hydrogen production hubs are planned in geographic regions addressing Western Canada and the U.S. (West Coast, Gulf Coast, Midwest and Mid-Atlantic). Twenty of the 60 hydrogen refueling stations are planned for California. Until a widespread hydrogen refueling infrastructure is in place, Nikola intends to dispense hydrogen via 700-bar mobile fuelers. “We think the mobile fuelers are a real competitive advantage for us,” Mendes said.
Trucks and fuel-cell power modules for the FCEV – as well as battery modules and packs for the BEV – will be assembled at Nikola’s Coolidge, Arizona, manufacturing facility at launch. “Our factory is flexible, so we can produce BEV or fuel-cell electric trucks on one or both lines,” Lohscheller said.
The Arizona manufacturing facility has capacity to produce 20,000 trucks annually. “We want to grow this step-by-step, so this is not overnight. This will take time,” Lohscheller added. For the European market, trucks will be assembled in Ulm, Germany.
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