Volvo Construction Equipment partnered with Waste Management (WM), the California Energy Commission and CALSTART to put its LX1 prototype electric hybrid wheel loader to the test: field test, that is. The company showcased the LX1 at a media event in July at WM's Redwood Landfill in Novato, CA.
Made up of 98% new parts, the LX1 prototype series hybrid has a fundamentally new machine design. It incorporates a driveline that consists of electric-drive motors mounted at the wheels, electric-driven hydraulics, a battery energy storage system, a significantly smaller diesel engine and new machine architecture including a new design of the lifting unit.
Decoupling all of its systems allowed for the physical architecture of the machine to change. “And that’s one of the big points that’s different about this wheel loader vs. the conventional and even some of the hybrid wheel loaders that are on the market today,” Scott Young, Volvo CE’s Director of Electromobility, told media at the event.
The electric motors drive each of the wheels and by having each of those four wheels drive independently, Volvo CE was able to change the frame of the machine.
With its electrically driven hydraulic system, Young explained “we were able to get more efficiency out of each of the subsystems.”
The LX1 prototype features a 3.6-L diesel engine compared to the 13-L on the baseline machine, the Volvo L150 wheel loader. “A machine that would do the work of this machine,” Young said, “it would generally have an 11 or 13 [liter engine].”
The LX1’s wheel hub motors allow the loading unit to be brought back farther into the machine, so that a smaller machine can do the work of a larger machine (one size larger, according to Volvo CE). Decoupling offers flexibility in terms of where things can be placed. “They’re not mechanically coupled together [so] we get modularity,” he explained. “And that modularity we see as something to really scale well not only for the wheel loader, but for other products.”
That higher efficiency offers ease to tune the machine to the operator needs. During field testing, if the operator needed something changed on the machine, Volvo CE engineers could access the software and adjust the machine to operator needs. “So we see a great opportunity in terms of tuning to the customer’s application,” Young said.
Collaborating on sustainability
Field testing of the LX1 prototype begin in late 2016. Volvo CE partnered with its customer Waste Management, which carried out the field tests, along with CALSTART, which conducted emission tests on the machine, and the California Energy Commission, which helped fund the LX1 project. Since the end of 2016, the LX1 has performed hundreds of hours of real work in two applications at Waste Management facilities in California.
The target set for this project was a 35% fuel efficiency improvement.
Testing began at the Redwood Landfill and Recycling Center, a green waste composting site in the northern part of California. Both fuel efficiency and greenhouse gas (GHG) emissions tests were conducted at the facility, and the results so far show an average improvement of 50% in fuel efficiency, which is equal to a reduction of 35% in fuel consumption and GHG emissions. The second test site was the Moreno Valley Transfer Station, which is a waste transfer site in southern California. The LX1 achieved an average fuel efficiency improvement of around 45%. Official results were to be provided to the California Energy Commission and CALSTART in September 2017.
In addition, there was a huge reduction in noise pollution compared to its conventional counterparts, according to Volvo CE.
The LX1 was also tested in Sweden and achieved similar results to those at the WM field test sites. In addition to checking the LX1’s efficiency in a real-life application, Volvo CE also sought operator feedback. “It’s fantastic to get this operator feedback to feed our future development projects [to] our engineers in Sweden,” Young said.
According to John Meese, WM’s Senior Director Heavy Equipment, being able to use available new technologies as a company “can improve our services to our end user—our customers—through our operations being enhanced. This was a project we thought would work for us.”
Each of the WM facilities had different needs from the wheel loader. At the Redwood Landfill, “we wanted that machine to be as nimble as possible," Meese said. "The electric drive that this gives us…we go from standing still to max operating, say speed, very, very quickly.”
He explained that Volvo CE was able to tweak the operation of the hydraulics to suit what the operator needed. In Redwood, there is a need for the bucket to fill or go up or dump faster, but that’s not necessary in Moreno; things might need to be slowed down there. “The design capabilities of this loader fit both operations very well with just a few tweakings of the software," Meese said.
The future for hybrid technology at Volvo CE
As far as exploring hybrid technology beyond wheel loaders, Young told Truck & Off-Highway Engineering that Volvo CE sees “an opportunity across all product lines we have today, but we are exploring things specifically in the haulers, excavators and wheel loaders at this time.”
To make hybrids more attractive compared to conventional technology, Volvo CE’s Kent Meyers, Director, Advanced Engineering Projects, said, "probably one of the biggest things is making it cost effective. Take this machine, it’s got a lot of new technology—98% of it is new. But I think getting something like this to a price point that the general population can afford, and is willing to pay for, is going to be one of the key hurdles.”
While it remains to be seen whether the LX1 wheel loader will make it from a research project to production, the enthusiasm about the machine and its future potential was apparent in Novato.