Most discussion of truck electrification has centered around powering the actual truck or tractor unit. Trailer electrification has mostly involved refrigeration units. But some companies believe the trailer itself can play a role in sustainable transport beyond aerodynamic add-ons.
Ecolution KWH is an e-mobility and power company that has received a U.S. patent for reusing wasted kinetic energy in refrigerated trailers. When combined with an electric or hydrogen-fueled truck, the company says, the Ecolution trailer accomplishes a total elimination of carbon emissions.
Ecolution’s “green perfect cycle” Module Active Response System, or Mars, replaces the diesel tank and transportation refrigeration unit genset typically used in reefer trailers with swappable batteries. As a result, it can reduce the average weight of a refrigerated trailer by 1,200 pounds, according to the company, increasing the hauling capacity of the trailer and delivering greater battery life for the electric truck.
The key innovation, according to the company, is the use of alternators connected to disc brakes in the trailer, sending power through a converter to a battery storage unit for on-demand energy, all within the reefer trailer.
The company now has four patents pending in Germany, Japan, China, and South Korea. The invention, under research and development for five years, now goes into a prototype in the U.S., Europe, Latin America, and Asia.
“The beauty of the discovery is in its simplicity,” said Johanne Medina Then, Chief Executive Officer of Ecolution. “And because the battery unit is located in the trailer, second-life Tesla and other electric vehicle batteries can be recycled, helping to eliminate yet another environmental problem.”
Chief Technology Officer Johnny Then Gautier adds, “The use case for Ecolution is even starker at the point of delivery, where there is a shortage of cold storage space in grocery stores. Reefers are often placed for hours or days in the parking lot, burning diesel to power their generators while they wait. That creates a serious noise, health and environmental problem.”
Trailer Dynamics, a German company, is working with Chinese battery maker Contemporary Amperex Technology Co. Limited (CATL) to develop the Newton eTrailer, which will launch in 2023 in Europe.
The Newton e-Trailer is an electric drive train that replaces one of the trailer’s conventional non-powered axles with an electric axle. In combination with the diesel vehicle, the entire tractor-trailer system is converted into an electric plug-in hybrid.
In combination with adaptive aerodynamics developed by Trailer Dynamics and the intelligent control strategy for the electric auxiliary drive, significant CO2 emission reductions will be achieved and diesel savings in average of 40% are possible, according to the company.
The Newton eTrailer is designed to respond to the driving behavior of its coupled tractor using integrated electric drive trains and provides support for it through an integrated electric transmission system, managing the electrical energy resources intelligently along the entire route. Both sides creatively apply the batteries to semi-trailers, while improving efficiency and also lowering operating expenses.
CATL is developing a 300 kWh lithium iron phosphate (LFP) battery with cell to pack (CTP) technology and cooling liquid for the Newton eTrailer.
Interestingly, U.S. truck electrification company Hyliion got its start developing a trailer product before it turned to the tractor.
As initially conceived, the Hyliion trailer product captured energy during braking and as a tractor-trailer runs downhill, and reapplied energy through a drive axle to help the truck launch and accelerate from a standstill and run uphill.
The Intelligent Electric Axle was a powered axle designed to replace a “passive” axle on a standard trailer tandem, and promised big fuel savings – 10 to 20% from hybrid-powered operation alone.
Hyliion pivoted to a tractor-based hybrid electrified product, this summer launched a fully electrified drivetrain, and just recently went public. But who knows, maybe we’ll see them go back to their roots at some point and add the electrified trailer back into the mix.