Electrified trailer cuts fuel consumption in semi-trucks by 36.3%

Range Energy makes truck trailers, with a clever connection to any standard tractor cab, loaded with electric powertrains to turn any semi into an efficient hybrid. They also let you push entire trailers around by hand at the depot in "shopping cart mode."

Range's 53-foot (16-m) RA-01 trailer packs its own 200-kWh battery, as well as an 800-volt e-axle powertrain that can put up to 14,000 Nm (10,326 lb-ft) of torque, at up to 350 kW (469 hp), through the rear wheels. The same battery also feeds a rear liftgate and powered landing gear.

It works with any electric or diesel-powered cab and is perfectly suitable for fleet operations, without any modification to the trucks. It takes its cues from a smart kingpin, which basically senses the acceleration and braking loads that the tractor is putting on the trailer, and uses its electric motors to help out.

Thus, when the cab accelerates and pulls on the kingpin, the motors add torque instantly and proportionally. And when the cab brakes and pushes back against the kingpin, the trailer kicks in with some regenerative braking.

In fuel economy testing performed by Mesilla Valley Transportation Solutions, Range reports a fuel economy boost of 3.25 mpg (72.4 L/100km) , representing a 36.9% efficiency gain against the test truck's standard fuel consumption.

"We're essentially matching the fuel economy you'd get if you were bobtailing your tractor," Range CRO and founder Ali Javidan tells The New Warehouse podcast – bobtailing in this case meaning driving the cab without a trailer attached.

The test was conducted on a "25.5-mile (41-km) urban/highway loop at approximately 59,000 lb (26,760 kg) gross vehicle weight and 60-mph (96.5-km/h) top speeds across multiple scenarios including stop/go and steady-speed portions."

We'd be interested in learning how that translates to real-world situations, where many of these trucks tend to spend the bulk of their time banging out big miles at constant highways speeds.

Range says its first trailers are targeting around a 40% efficiency boost over a range of 200 miles (322 km) – "In a highly loaded city drive cycle, that number's actually 48%," says Javidan, "on a mixed highway and city cycle, it's 41%, and if we're looking at just over the road long-haul trucking, it's a little bit lower than that."

Even beyond that 200-mile range once the battery is completely depleted, Range still expects about a 10-15% efficiency boost over a regular trailer for the rest of the trip, simply through the energy it can capture and release through regenerative braking.

Javidan channels Mitch Hedberg when talking about what happens in a total system failure.

"It's still a trailer, we default as a trailer," he says. "One of the analogies the guys use is that we're like an escalator. We help you get up to the top, but if we fail, we're still stairs ... Worst case scenario, if all the Silicon Valley bullsh#t fails, it's still a trailer."

The trailer can be charged at either end of the journey, taking 10.5 hours on an AC connection, or as little as 45 minutes using a 350-kW DC fast charger.

There are other benefits; drivers apparently enjoy the lightness and safety factor of driving with the powered trailer, and the fact that it reacts to engine braking just as much as it does to the brake pedal, meaning that it's more relaxing to drive down a hill than an unpowered heavy trailer.

And then there's "shopping cart mode" – which uses a similar control approach to let you disconnect a fully-loaded trailer from the truck and push it around manually like a hand trolley, with the electric motors helping all the way. This system appears still to be at the prototype stage, but you can get an idea of what it'll be like in the video below.

And Range is building it for future flexibility beyond just the fact that it'll work easily with electric or hydrogen-powered cabs. The battery pack, for example, could be adapted to power a refrigerated trailer. The system has been set up to make it possible, some time in the future, to integrate it with other control systems that might allow larger logistics operations to have trailers move around certain facilities by remote control or autonomously.

"We are beginning to deploy these with our first customers this year, and the goal here is to start scale production in 2024, probably late 2024," says Javidan. "We'll start seeing these things in volume on the roadways, I'd say, in early 2025."

There's no information as yet on the price of the trailers, but given the epic amounts of fuel a typical semi burns in a year, we imagine the business case over time will look pretty dang decent. This seems to us a great way to begin soft-decarbonizing land transport operations without needing big infrastructure changes or the retirement of existing trucks. We look forward to seeing how things develop for Range.

Source: Range Energy