MIT develops hybrid engine for long-haul trucking as industry adapts to emissions standards

by Jeff Della Rosa ([email protected]) 1,349 views 

While the battery-powered electric Tesla Semi might not be available for carriers in 2019, researchers at the Massachusetts Institute of Technology (MIT) have developed a plug-in hybrid engine that could be used for long-haul trucking and help meet emissions standards that look to reduce the size of big rig engines.

A recent article by the MIT Center for Transportation & Logistics showed researchers at MIT’s Energy Initiative and Plasma Fusion and Science Center have developed a hybrid engine that runs on gasoline, costs less than diesel engines and performs as well as the traditional engines. The hybrid engine would also resolve the issue of having a large number of batteries when it comes to long-haul trucking. The weight of the batteries range between 10 and 15 tons, and this comprises a large portion of a truck’s payload, said Leslie Bromberg, principal research engineer for the Plasma Fusion and Science Center.

Other issues with battery-powered electric trucks include limited charging infrastructure and the time it takes to recharge batteries, Bromberg said, adding that this could restrict battery-powered trucks to shorter routes. With regard to the Tesla Semi, Lowell-based carrier J.B. Hunt Transport Services Inc. had planned to use the battery-powered electric big rig for its intermodal and dedicated segments on the West Coast. Bentonville-based retailer Walmart also reserved the big rigs to test them in the United States and Canada as part of its alternative fuel strategy. The Tesla Semi is expected to be available in 2020, the article noted.

John Kent, clinical associate professor in the supply chain management department of the Sam M. Walton College of Business at the University of Arkansas, said the concept hybrid engine looks to reach a larger market.

“Hybrids should be able to go coast-to-coast,” Kent said. “Hybrid cars can.” He expects that large private and for-hire carriers will test them as soon as they’re available. “They’ve probably already seen presentations,” he said. “Many businesses view sustainability as providing both economic and environmental benefits, and hybrids fit this strategy well.”

All-electric vehicles will handle city pick-up and delivery for trips of less than 300 miles per day, Kent said. In December 2018, J.B. Hunt announced it had added five Mitsubishi Fuso eCanter trucks to its fleet as the carrier’s first all-electric trucks. The trucks are being used to haul freight for retailers and be used for home delivery of bulky items, such as appliances and furniture. The trucks have a 60-80 mile driving range and can be charged up to 80% in one to two hours. They were to be used in Santa Fe Springs, Calif., and the Houston area and part of the carrier’s Final Mile Services network, within its Dedicated Contract Services segment. Second-quarter revenue in the segment increased 28% to $680 million, and Final Mile revenue rose $49 million as a result of the February purchase of New Jersey-based carrier Cory 1st Choice Home Delivery.

Bromberg said a viable battery-electric engine for heavy-duty trucks won’t be available for years, even as battery technology continues to develop. The concept hybrid engine would offer an interim solution and help to guide long-haul trucking toward an emissions-free future, he said. It would charge an onboard battery and run on gasoline, ethanol, methanol or a blend of the fuels. Compared to a diesel engine, the gasoline engine would have lower NOx emissions, and the flexible fuel options would be cleaner with regard to greenhouse gas and particulate emissions. The concept engine would produce one-tenth of the air pollution that traditional diesel trucks produce, he said.

“Importantly, the hybrid-based powertrain is lighter and cheaper than its diesel equivalent,” according to the article. “It could cut the price of a heavy-duty truck by $15,000 to $20,000. The hybrid might also become an attractive choice for truck owners and operators under pressure to comply with increasingly stringent emissions standards.”

Maintenance costs are higher for the flex-fuel engine, but the concept hybrid engine is economically viable for long-haul routes, the article shows. It’s also flexible in the types of batteries it can charge, or the batteries can be charged by a variety of generators, including fuel cells.

In a recent note about engine displacement trends, Tom Rhein, president of Rhein Associates, said new emissions regulations expected in 2024 will accelerate the trend toward smaller displacement engines for Class 8 trucks, the largest truck class. While the larger engines will comprise the largest share of engines in 2019, more than 85% of Class 8 trucks produced between 2020 and 2024 are expected to have smaller displacements.

“Diesel power is under attack long-term for use in on-highway commercial vehicles,” said Kenny Vieth, president and senior analyst at ACT Research. “Alternative power is being developed, tested and refined, even as diesel engines are transitioning to become more fuel-efficient and clean. Emission regulations are one of the main drivers of alternative fuel adoption. While many think this is a California-only phenomenon, we would note that Oregon’s legislators recently voted in favor of a bill to regulate diesel trucks in the Portland metro area, and we continue to see reports about various state and federal-level funding for alternative fuel programs that are sending millions of dollars toward these efforts for both commercial and passenger vehicle use.”