London, UK: Systems using the kinetic energy available from truck axles have been around for a long time but have never proved popular with operators. Until now that is.
What’s changed is the ability to more easily use the electricity generated from a trailer axle to power equipment such as fridges which are now increasingly electrical rather than diesel powered.
There is also the attraction to adopt systems that cut carbon emissions. Operators are spoilt for choice with systems from fridge makers Carrier Transicold and Thermo King, as well a trailer builders such as Schmitz Cargobull, Krone, SDC, Montracon, and others.
Krone was awarded the European Transport Prize for Sustainability in 2014 for recuperation technology used in a Krone prototype Cool Liner trailer. “The innovation related to aerodynamics, recuperation and telematics uses various means to enable the time and energy consumption of the trailers to be significantly reduced,” Frank Albers, sales manager, Krone, said.
Dutch trailer maker, Valx has an axle generator in 2020 configured to electrically power on-board fridges. Valx sales director, Martin van Willigen, said that with an integrated power generation system fitted to the axles of trailing equipment, there are opportunities, in theory, for fleet operators to achieve significant operational and fuel efficiencies, especially if this technology could be used to share the load of connected systems that draw electricity. Valx showed the concept at the IAA Commercial Vehicles Show in 2012.
UK operator Fowler Welch tested a kinetic energy-powered fridge trailer from International Refrigeration Cooling. The trailer uses a system developed by International Refrigeration Cooling from a US design, sold and supported in the UK by Montracon, which demonstrated a similar trailer at the CV Show.
“The guys at Fowler Welch saw the potential and approached us to develop the trailer for their operation,” says Brian Arnold, president, of British-based International Refrigeration Cooling, talking to Cold Chain News. “Thermo King stepped in and helped develop the control system that allows the fridge unit to interact with our system based on high and low voltage and allows the system to switch back and forth between diesel and electric automatically,” he says.
The system lends itself to retrofit, as was the case with the Fowler Welch test unit. The generator attaches to one of the trailer axles with clamps and a few spot welds. The system converts kinetic energy from the wheels to generate electrical power which allows the fridge to run while the vehicle is in motion. The system also charges in-built batteries from as little as 5-7 mph allowing up to 90 minutes of stationary power before the hybrid motor kicks in.
The fridge electric motor is changed from the standard alternating current unit to a direct current unit to allow it to take power from the generator. The fridge is still able to use shore-based power supplies with an inverter to convert the AC to DC.
The trailer, which operates from Fowler Welch’s Spalding depot, was retrofitted with the new system which adds 500kg to the trailer’s unladen weight. The trailer had a Thermo King SLXe 50 Spectrum S3 fridge with the next generation, low global warming potential refrigerant, R452A.
In the United States, where the system has been operating over the past three years, McDonalds, among others, uses it to power tail lifts and pallet trucks. “McDonald’s has been able to reduce the idle time of trucks, that typically make 30 drops a day, by 14 hours per week. That’s provided quite substantial savings,” Arnold says.
The Fowler Welch installation is not a prototype but a production ready system, Arnold says. “We have volume production. We are good and ready to go ,” he says. Payback on the system varies with the particular operation but typically is within 140,000 miles; that’s less than a year in Fowler Welch’s case, he says.
The key advantages of International Refrigeration Cooling’s auxiliary charging system are reduced fridge fuel consumption, reduced CO2 emissions and far less noise when the fridge is on electric power. Initial noise measures show the unit producing 56dB at 15 feet with doors open. “And we can get better than that with some additional measures,” Arnold says.
Paul Allera, head of fleet, Fowler Welch, said: “The new trailer enables us to manage deliveries in areas with noise restrictions by negating the use of the unit’s diesel engine to power the trailer and it decreases the volume of fuel needed, helping us to reduce CO2 emissions and operating costs.”
Carrier Transicold won the John Connell Innovation Award from the Noise Abatement Society for its system that converts kinetic energy generated by the trailer axle and brakes into electricity, stored in a battery to power the fridge. The E-Drive technology eliminates the noise producing mechanical drive train and diesel engine. The unit is certified as operating below the Piek 60dB(A) standard.
BPW’s E-Power axle, which converts energy from the vehicle and its braking system into a continuous power source for trailer fridges, is the latest innovation for Thermo King.
The AxlePower technology is an integrated system combining Thermo King hybrid or fully electric trailer fridges, BPW’s E-Power axle energy recovery system, and battery storage.
The system stores the energy generated while the vehicle is rolling or braking in a high voltage battery and reuses it to power the fridge. The AxlePower system is tractor-independent, which makes it easy to deploy across the customer’s fleet, Thermo King says. The technology also offers immediate compatibility with all Thermo King and Frigoblock trailer refrigeration units.
Francesco Incalza, president, Thermo King, Europe, Middle East and Africa, said: “Today, combining our expertise, research and development with BPW, we’re introducing new technology that turns the energy typically lost by a trailer during transit into into clean, sustainable power for trailer refrigeration units.”
The possibility to recover and reuse energy makes the AxlePower system an ideal solution to increase the sustainability of all types of trailer journeys. With silent running and no CO2 emissions when operating from the battery-pack, this technology allows customers to easily run inner-city deliveries, including in ultra-low emission zones, Thermo King says.
Laurent Debias, VP product management and marketing at Thermo King, said: “The AxlePower technology represents a significant advancement in both operational flexibility and long-term sustainability of refrigerated trailer fleets. Enabling this form of electric power supply recovering energy that would typically be lost, allows for significant emissions and cost gains during every single journey. This is especially important in a price competitive industry like commercial transport.”
Krone and its Dutch partner THT received an award for the Cool Liner “THT New Cool”. Krone converted the Cool Liner to electric operation in cooperation with the electric specialist THT. The second trailer axle was converted to a recuperation axle, which feeds electrical energy to a battery pack mounted longitudinally under the trailer. The third-generation energy storage unit, which weighs 320kg, supplies the all-electric refrigeration unit with electricity with the help of intelligent control electronics, so that the “THT New Cool” Cool Liner does not need a diesel unit at all. The total weight of the fully electric refrigerated trailer is the same as that of a conventionally refrigerated trailer with a full diesel tank.
