Have you heard? With all the cutting-edge technology invading the trucking and transportation sectors, it wouldn’t be long before trailers became their own self-sustaining power source. Trailer OEMs are hard at work figuring out how to get the most out of their trailer configurations.
One trailer manufacturer has developed a refrigeration system that replaces the diesel tank with swappable battery modules that can be charged by capturing kinetic energy from the wheels and transferring that energy to the refrigeration module. Do we live in the 21st century, or what?
Certainly, most of the discussion around electrification of tractor trailers has centered around the rigs themselves. Tractor units have been evolving at leaps and bounds, with OEMs increasingly finding unique ways to electrify their vehicles. And with states like California pushing the industry to make change, it is no surprise that manufacturers are answering the call.
The Trailer Takes Center Stage
Today, tractors are not the only factor in discussion. Some companies feel they can develop the trailer to play a more important role in sustainable transportation. And this could be through more than just aerodynamic add-ons. While aerodynamic accessories have come a long way, there is plenty more trailer real estate to use for sustainable goals.
As we discussed earlier, a lot of the conversation right now is how to capture wasted kinetic energy to power reefer units. The company that is pioneering this methodology for green efforts, but it also eliminates the average trailer wright on a reefer trailer by nearly 1,200 pounds. This is no small number. Removing that kind of weight can have a big impact on fuel economy. And for trucking companies using this technology on an electric or hydrogen-powered truck, you have net zero emissions.
The key innovation in this type of technology is the use of alternators. Alternating devices can be attached to disc brakes on the trailer. Much like the way Priuses use disc braking energy for power, a convertor catches the energy and stores it in the battery for on-demand energy. This all happens within a closed system inside the trailer.
Using these technologies also allows OEMs to make use of old or discarded batteries. Since the battery units are in the trailer, second-life batteries are an easy option. This eliminates another environmental problem of how to deal with battery waste. Giving them this kind of second life helps keep the system closed.
Meet the eTrailer
Advanced trailer electrification technologies are important at the point of delivery. Consider that there is generally a shortage of cold storage space at grocery stores. It is not uncommon for reefer trucks to be waiting for hours in a lot, burning a lot of diesel fuel as they sit idle keeping things cold. Not only is this a fuel economy problem, it is a noise, health, and environmental problem.
Another country addressing these problems is Germany by partnering with a Chinese battery maker on what they are officially dubbing an “eTrailer.” The eTrailer utilizes an electric drive train that replaces one of the trailer’s standard axles with an electric axle. When used in combination with a diesel rig, the system creates an electric plug-in hybrid loop.
The company developing this system states that when used with adaptive aerodynamics and a software-based intelligent control for the electric auxiliary drive, trucking companies using the system could see fuel savings of up to 40% for each unit using the system.
The advanced eTrailer is designed to respond to specific truck driver behaviors and patterns. It is coupled to the tracker using an integrated electric drive train and transmission system. The entire system can manage energy resources intelligently, using machine learning, as the truck driver completes their route. Systems like these both lower operating costs and improve fleet efficiency.
Now the company is developing an enhanced, 300 kWh lithium iron phosphate battery with cell to pack technology. This is seriously futuristic stuff that could have a significant impact on emissions and overall fuel usage across a fleet.
Say Hello to the EHub
Seems like every new advance in just about every industry has an “e” at the beginning of its name! Our latest example is the EHub for trailers, which is a motor/generator package mounted at the wheel-end within the space between the axle spindle and brake shoes. The company behind this setup deftly used existing space instead of requiring tractor design changes.
The EHub system can generate power directly from the rotation of the wheels, whether on regional or urban delivery routes. The system can supply enough power to the reefer unit throughout the day. And when the battery is at full charge, the system can be used to power auxiliary systems on the trailer, such as lighting or adaptive aerodynamic systems.
Even better, battery-powered trailer solutions are practically noiseless. This creates a lot of possibilities for trucking companies delivering at times of night where noise restrictions come into play. Integrated controls built into the system allow for a regenerative braking or propulsion assist mode. This enables the system to make use of all the power captured throughout the day and further optimize fuel savings.
The Power of Solar
We have talked before about how solar is being utilized in trailers. This is an ongoing trend. Companies are getting in on the solar game, with one developing a trailer entirely covered in solar cells. The energy harvested from the solar cells turns the rig into a plug-in hybrid truck.
In Sweden, where the setup is being tested, trucks are returning an average fuel savings of 5 to 10%. In Sweden, there is enough sunlight from spring to autumn to generate energy. And even in the summer, when the sun is weaker, there is enough energy to provide a significant boost when these trailers are used.
In Spain, where the sun is plentiful, test companies are seeing savings of 10 to 20%. Unlike Sweden, southern Spain has 80 more hours of sunlight, which provides an excellent training ground for technologies of this type.
Manufacturing industries have a lot of experience designing solar cell concepts for boats and caravans, but usually only as reefer power sources and cookers, but not the actual powertrain. With the latest advances in technology, that paradigm is changing.
Trucks utilizing the novel solar concept being tested in Sweden and Spain are running 18-meter long solar cell trailers with a total area along each side of 140 square meters. It is expected that the trailers being tested in Sweden will provide up to 14,000 kWh of power for their big rigs.
Fortunately, this test will provide a lot of answers to other OEMs who want to develop these kinds of technologies. Research projects like these provide data on whether a trailer can feed electricity directly into the grid when fully charged and the truck is parked. Integrations like this into existing power grids will be critical to get these systems off the ground and adopted by large, medium, and small trucking companies alike.
Fancy New Axle Configurations
One part of the tractor trailer that seemed destined to never change until the age of electrification was the powertrain. Drive axles have remained largely unchanged for a very long time. But now, thanks to new entrants into the market, intelligent electric axles represent a new front in the sustainability push for big rigs and trailers.
Intelligent electric axles are designed to replace what are now called “passive” axles on tandem trailer setups. By creating an intelligent axle setup, you essentially turn your tractor-trailer combo into a hybrid setup. This can save up to 20% on average fuel costs, according to the companies developing these products.
Between electrified hybrid drivetrains, solar, and other innovations, expect to see the standard big rig setup continue to evolve. As we move towards an automated and greener future. OEMs and trucking companies will need to partner up to ensure sustainability goals are met while trucking companies still get the performance and capabilities they need out of their big rigs.