As a mechanical engineering student at Carnegie Melon, Thomas Healy wondered why passenger cars were moving toward electrification, but commercial trucks were not. That curiosity has led to one of the greenest, most innovative, trucking concepts on the planet. “I learned that there had been some electric trucks made, but at that point they were built on lead acid batteries and outdated technology by today’s standards,” he said.

Even as battery technology improved, Healy knew that trucks were not going to be fully electric any time soon. To get anything like the range that of a typical diesel semi, an electric truck would have to give a third of its capacity to batteries. “We said, hey, the better mousetrap here is to create a range extender truck where we actually bring the power plant with you, and we charge the batteries as you’re going down the road.”

Healy planned to replace the wheel and axle assembly underneath the trailer (the slider) with an electric motor driven system. It would capture wasted energy while going downhill, charging batteries for a boost during acceleration and uphill travel. With that concept, Hyliion was born. Healy, now the company’s CEO, began entering business plan competitions and, in 2016, won the Create the Future Design Contest.

Six years later, the company’s hybrid powertrain — called the Hybrid eX — has traversed millions of highways miles. But the e-axel has moved up from the trailer to the truck itself, to meet the needs of trucking companies, who often own several trailers for every tractor. “Fleets were saying, ‘Hey, if you just put this on the tractor, I only have to buy one and I get all the same benefits,” said Healy.

The Hybrid eX, is, arguably, a short-term solution. Companies that are looking to move away from diesel tend to want to leapfrog to full electrification, rather than invest in what they might see as a half-way measure. But an entirely battery powered truck is, currently, just not feasible. There’s the range, there’s charging time, and there’s infrastructure. “Right now, there are very few stations built out in the United States that can charge a truck at a fast rate — you can probably count them on a couple of hands,” he said. Constructing a facility that could charge 100 trucks, for instance, would be like adding 50 manufacturing plants to the grid in a single area.

So, Hyliion created the Hypertruck ERX, which retains the regenerative braking capabilities of the hybrid but adds a natural gas fueled generator to charge the battery as well. “With natural gas, there are over 700 stations already in existence in North America. The trucks we are deploying can pull up, fuel up, and they’re back on the road in about 10 minutes,” explained Healey.

The Hypertruck ERX will go into trials later this year and Hyliion hopes to have them on the road in the latter half of 2023. Meanwhile, they are getting ready for an eventual shift to hydrogen. “Batteries today are plenty fine for what we’re doing. The area for evolution is having a more efficient generator on the truck,” said Healy. “We plan to have a fuel-agnostic generator and then a fuel-cell generator that runs on hydrogen, over time. With each one of those steps, we can move to more and more efficient power generation, with the ultimate goal of being more efficient than a power plant.

“We’re tackling all the problems as they come in and solving them. But as every engineer appreciates, if it were easy, everyone would be doing it.” Michael Abrams is a science and engineering writer based in New Jersey.

2016 Grand Prize Winner

INNOVATOR: Thomas Healy, CEO, Hyliion

INNOVATION: Hybrid electric technology for semi-trailers and the trucking industry.

IMPACT: The system helps truck fleets to reduce gas emissions and fuel costs. Regenerative braking captures and reuses power to help the truck move uphill.

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