By Treena HeinFeatures Rental Equipment Tech tips electrification
Hybrid power could be the compromise between utility and sustainability.
When they send out hybrid equipment with customers in most winter conditions, rental business owners in Canada can take heart – performance should be solid.
In the battle against climate change, converting all our power supllies to electricity is key because electricity can be generated by clean sources such as hydroelectric, nuclear, solar and wind. That’s why governments are urging equipment manufacturers to introduce electricfied options, and most have responded with lithium-ion battery designs.
Of course, any battery pack is going to perform better during winter in warmer areas of the country like southern B.C. or southern Ontario but, as J.P. Ouellette explains, “hybrid performance would be equivalent or better.”
Ouellette, who is the business development manager at M-K Power Products in Mississauga, Ont., adds that “all batteries are affected somewhat in extreme cold weather. But the need to just warm up a slight bit initially at the beginning of operation is like any other engine in similar conditions.”
Hybrid equipment is attracting strong current interest across Canada’s rental sector as it’s increasingly popular among customers who want to show the public they are going greener. Ouellette notes that certain customer groups may require specific hybrid solutions for various worksites due to the goals and mandates of corporations or local governments.
He also explains that because the battery power in hybrid machines lowers the overall horsepower required to run a machine, hybrid systems typically cause any piece of equipment to drop down an emissions category, “thus making it easier to comply with regulations.” For example, in applications requiring an engine of 56 kilowatts or more due momentary high loads, it’s possible to consider installing a hybrid engine of less than 56 kilowatts. Kubota has also given the example of a three-cylinder engine equipped with Kubota’s Micro-Hybrid system, which can achieve similar levels of performance as a conventional four-cylinder engine.
To make sound equipment investments, rental firm owners also need to keep a close eye on hybrid technology as it evolves. Ouellette foresees that over the next few years, there will be improvements in battery storage and more battery power (and also, hybrid systems will surely decrease in size, as any new technology tends to do). But even at today’s level of technology, he believes everyone should now be actively investigating hybrids. “It is the future of our industry,” he says, “and rental companies need to be prepared for what is coming.”
Grant Van Tine, product manager of electric vehicles for John Deere, says many customers are curious about the benefits of hybrid machines and want to try them before they buy them. “Rental companies have a great opportunity to enable contractors to put hybrid machines into their operations on a rental basis and experience first-hand the benefits they can offer in terms of performance and fuel savings,” he says. “Hybrid machines are easy to integrate into any fleet, given the similarities in operation, maintenance and fueling.”
As to whether there are hybrid equipment options in development or on the market that use propane or liquid natural gas, Ouellette can report that Kubota is starting with diesel hybrids since most of its customer base already uses diesel but at the same time he believes there are future opportunities for all fuel types. He notes that the LNG and propane power spark engines will be able to be mated to hybrid systems in the near future, just like combustion engines can be mated now.
Currently, Deere hybrids support the use of petroleum diesel, renewable diesel/hydrotreated vegetable oil and certain blends of biodiesel. Deere is investigating and testing additional alternative fuels for potential future use.
High on hybrid
Genie is one aerial manufacturer that is particularly enthusiastic about hybrid power on its MEWPs, offering the Z-60 and Z-45 articulated boom lifts in FE versions designated “fuel-electric.” The company says the diesel engine can power the batteries to full charge in about four hours and operate for twice as long in full hybrid mode as a full diesel with half the fuel. Genie’s design allows the operator to switch between full electric, full diesel and hybrid running modes. So the user can go full electric for indoor work where exhaust is not allowed, full diesel for tough rough terrain conditions, and hybrid to maximize run time. That kind of flexibility is critical to a rental store, allowing it to offer the same machine for almost any application. A quick search reveals several other major aerial OEMs are offering hybrid versions, including JLG, Snorkel and Sinoboom.
Engine performance and maintenance
Similarly to overall performance, Ouellette reports that hybrid equipment engines achieve the same or better performance levels as combustion engines. “The power is on tap in the hybrid system, ready to assist the moment it’s required,” he explains. He adds that in certain hybrid architectures like the Kubota P2, you can also have an electric-only mode or engine-plus-electric boost.
Ouellette points to the model he represents as an example of the latest technology. The Kubota V3307 Micro-Hybrid system includes an AC synchronous motor generator, a DC/DC converter and a 48-volt lithium-ion battery along with a 74.3-horsepower model V3307 diesel engine to provide 10 kilowatts of power assistance during peak overloads. The Micro-Hybrid prototype debuted at ConExpo in 2020, and is intended for wheel loaders, rollers, excavators, forklifts and generator sets. It’s slated to be in production in early 2024.
In general, most of the maintenance considerations with hybrid systems concern keeping the batteries in good shape. Regarding Kubota systems, Ouellette adds that replacement of the micro-V belt for some motor-generator configurations may be required, and eventually a battery replacement as well, “but these systems are designed for long life and durability.”
Maintenance time is also saved in a hybrid system. Because there’s no after-treatment emissions device (Selective Catalytic Reduction) for diesel engines 56 kilowatts or larger, diesel engine fluid top-up is not required. Kubota’s new D1803 P1 hybrid engine has a maintenance-free design and a beltless motor generator. It was previewed at ConExpo 2023 and will likely be produced starting in 2025. It’s a turbocharged engine with a turbo after-cooler and DOC-only after-treatment with an output of 49.6 horsepower at a rated speed of 2,700 RPM. The motor generator offers an additional boost of 10 kilowatts when needed with a 48-volt lithium-ion battery pack.
Kubota states that it’s considering how to approach Micro-Hybrid retrofit as a kit, but nothing has been decided on this since the system is in the initial phases of commercialization (production early 2024). The combined size of the Micro-Hybrid components (converter, battery and motor generator) is similar to that of a common rail engine.
Adding a Micro-Hybrid kit to existing equipment would enhance value with minimal cost. There is no impact on power take-off, so the system can also be added for applications currently under development by OEMs (no need to change product design, and Kubota will offer a package of the required peripheral components). As to whether it’s wise for rental companies to add the Micro-Hybrid components to their existing Kubota equipment next year, a Kubota representative suggests that a more successful early approach would likely be found in re-powering large fleets, “where there is some volume to the opportunity.”
The D1803 P1 Hybrid engine can also be installed into existing applications by OEMs, as can the D1105 P2 Hybrid starting in or around 2025 (date to be determined).
Rental companies should consider that equipment already equipped with a Kubota engine can be converted to Micro-Hybrid by installing three main components (converter, battery and motor generator), in total a size similar to that of a common rail engine. This allows equipment owners to enhance the value of their existing applications with a minimal development cost. There is no impact on power take-off, so it can be used for both existing applications or for applications currently under development. There’s no need to change product design, and Kubota offers a package of the required peripheral components.
The D1803 P1 Hybrid engine can also be installed into existing applications by OEMs, as can the D1105 P2 Hybrid starting in 2025, when it will be launched. Offering a rated output of 24.8 horsepower at 3,000 RPM, the D1803 P2 has a one-way clutch that is incorporated into the Kubota-supplied gearbox. The P2 Hybrid system from Kubota offers the ability to switch between engine drive and electric motor drive while in operation. The engine can be used when moving between locations, but if there are areas where emissions or noise are a concern, the engine can be stopped and switched to the electric motor.
Deere announced three additional hybrid models at ConExpo that will be available soon: 744 and 824 X-tier wheel loaders and 850 X-tier dozer, which when launched will bring Deere’s total to five hybrid models. As announced with Deere’s “Leap Ambitions,” Deere is planning to have over 20 diesel-electric and battery electric models by 2026. The John Deere E-Drive (hybrid) models are designed to work and are tested in the same conditions as their diesel equivalents,” says Van Tine. “Collectively, the 644 X-Tier and 944 X-Tier E-Drive wheel loaders have accumulated over three million customer hours working in the same environments as loaders with conventional drivetrains. Generally speaking, hybrid machines are more efficient and offer greater performance than conventional machines. By eliminating the torque converter in the drivetrain, hybrids allow more power to be delivered to the ground, improving performance.”
Hybrid generators and lifts
Hybrid generators (diesel with battery energy storage systems or BESS) are currently offered by many rental stores in Canada. These units consist of a battery system, inverters and load-sensing controllers that automatically switch power sources to maximize efficiency. When the diesel generator is in use due to battery depletion or high loads, excess power from the diesel motor recharges the BESS. When the load is lowered, the generator is shut off and the BESS carries the load on its own.
Of course, maintenance is less with hybrid generators compared to all-diesel systems. The diesel runtime is reduced, which means longer service intervals, lower consumption of oil and filters and longer equipment lifespan. In July, United Rentals released a white paper, “Hybrid Power Solutions: The Future of Portable Power,” and stated that “in a recent project, a large construction customer reduced cost by 34 percent and reduced generator runtime by two-thirds.”
United Rentals’ hybrid generator, which has a high-density lithium battery system, offers 40 to 60 kilowatts of power output and provides between 60 and 120 kilowatt-hours of storage. The company has recently reported that about a third of its national motorized fleet is now hybrid or electric.
Diesel engine recharge of the batteries is also offered with Genie’s fuel-electric boom lifts, which have been on the market since about 2020. Among the three hybrid models, two articulating, the Genie Z-60 FE hybrid boom lift works on any surface including soft and loose rough terrain and operates for more than a week on a tank of fuel and a full day’s shift on one battery charge.
These lifts automatically turn on the generator only when needed. The electric motor/generator feeds the battery and drives a hydraulic pump that powers the machine’s lifting movements. The battery also powers the unit’s four AC drive motors that also serve as generators by recuperating energy produced during braking, which charges the batteries.
Hybrid power is still relatively new in the construction equipment sector and many OEMs seem more focused on providing electric-only solutions. But in a world where we need to reduce emissions but still need to get things done in the cold, hybrid power may be a critical answer.
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