Choosing Hybrid

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“The worse the route or driver behavior, the more effective the system, because it doesn’t allow the driver to abuse the truck.”

-Scott Kanne, Wayne Engineering

“There is a trend in developing hydraulic, battery, and ultracapacitor hybrids, and the regulatory agencies want to understand the technologies and their impact on emissions.”

-Andrew Burnette, InfoWedge

The market for hybrid-drive refuse vehicles is gaining momentum as more municipalities complete pilot programs and place their orders. But that’s not the whole story, because hybrid technology has spawned a number of fuel efficiency technologies, and, as would be expected, new designs and approaches are entering the market.

No discussion of hybrids would be complete without covering the progress of Parker Hannifin and Eaton Corp. Both companies are based in Cleveland, OH, and both have been innovators in hybrid-drive technology. In the case of Parker, its RunWise Advanced Series Hybrid Drive began field testing in 2008, and the industry has watched closely. Could the concept of using recovered brake energy stored in a hydrostatic mechanism (or more commonly called a hydraulic system) deliver significant fuel savings? And, of course, could the savings deliver a reasonable return on investment? And are there competitors with other technologies? Well, those are three complicated questions that could all be answered, respectively: definitely, maybe, and most assuredly. But more information would help if it’s time to consider adding a hybrid to your fleet. So let’s take a deeper look.

Parker took the question of fuel efficiency off the table in March 2012 when it announced the results of a year’s worth of pilot tests in several communities in South Florida. The RunWise system as installed on Autocar E3 refuse vehicles averaged 43% reduced fuel consumption compared with their conventional diesel counterparts. Testing included monitoring brake wear, and an independent party verified that the replacement cycle for brakes on the E3s lengthened from 12 weeks, to 102 weeks.

The results are all the more impressive when compared with Parker’s first field trial in Texas, where an E3 spent 10 days of evaluation with a private fleet operator on an existing route of 1,200 homes. The E3 turned in fuel savings of 27%, plus 3% more cans and 3% more tonnage collected per day. Parker credited the test in Texas and four other states as helping to improve quality and develop product enhancements, though details weren’t specified.

The benefits of pickup and tonnage gains makes the case for an overall boost in fuel economy, according to Parker. For example, the results of fuel economy monitoring during field tests in Michigan measured an average savings of 38%. But factoring in the overall increase in pickup and tonnage equals a new adjusted average fuel savings of 45%. Then, too, there are significant benefits of lower emissions, and lower wear and tear on engines that are assisted in launching the truck.

Reduced emissions have been a mainstay of justification for the high cost of hybrid technology, and the benefit was cited as a factor in purchasing more E3s by officials in the city of Miami (five vehicles) and Miami-Dade County (six vehicles). Other municipalities placing orders include Texas, North Carolina, Florida, and Indiana. At its debut in Indianapolis, IN, the addition of a Runwise Hybrid refuse truck to the city of Seymour’s fleet demonstrated that hybrid technology can also rack up green mileage with the media.

At a well-attended event for television and the press, the Greater Indiana Green Cities Coalition hailed the acquisition of an E3 as the first to be deployed in the entire Midwest and a demonstration of dramatic fuel savings and significantly reduced emissions. According to Kellie Walsh, executive director of Greater Indiana Clean Cities Coalition, assisting coalition members in the deployment of alternative fuels and technology is part of the mission. Moreover, the deployment of an E3 is a boost to the state because 90% of the components making up the vehicle were built and installed by workers in Indiana’s green transportation industry.

“The City of Seymour is using the truck in a curbside recycling program,” says Walsh. “Originally they were using a pickup truck towing a trailer and driving behind the refuse vehicle, so this is really huge for them and it’s allowed them to keep the program free to residents.” Acquisition of the E3 was funded in part by a grant from Lt. Gov. Becky Skillman’s Office of Energy Development, and it’s notable that the E3 hybrids have attracted grants or supplemental funding at many cities and counties where they’re operating.

For example, sanitation department officials at the city of College Station, TX, reported that a grant was needed for their new E3, as its price was about $380,000, well over the $270,000 cost of a comparable diesel truck without a hybrid system. A grant from the US Department of Energy (DOE) for $110,000 made the purchase possible. Other principal hybrid supporters with grant money include the US Army National Automotive Center (NAC), and Pasadena, CA-based, CALSTART’s Hybrid Truck Users Forum.

As a member-supported organization of more than 140 firms, fleets, and agencies worldwide, CALSTART packs a strong punch as a successful advocate of high-tech, clean transportation. And it has the prize money to match, with a 2012 budget for incentives of about $11 million. In 2009, CALSTART and the NAC provided funding for the New York City Department of Sanitation’s launch of a pilot program, to test three hybrid-drive refuse trucks. The Crane Carrier Corp., of Tulsa, OK, supplied two Mack Trucks vehicles with its systems: one hydraulic-based, the others with parallel electric power trains that convert braking energy to electricity stored in lithium-ion batteries.

In August 2012, the NY Sanitation Department announced the acquisition of five more Mack hybrids-all equipped with electric power trains. Mack describes the technology as a joint development of Mack and its parent company, Volvo. Mack also announced that later it would supply New York with an additional 14 hydraulic system-based hybrids.

There’s no official announcement of how New York is funding the latest acquisitions, but if it were testing Autocar E3s, leasing would be an option. In May 2012 Parker Hybrid Drives Systems announced a leasing program with Wells Fargo Equipment Finance for select Autocar dealerships in the US. Parker Hybrid Drives System general manager Shane Terblanche noted that leasing could have a positive impact on preserving capital at commercial haulers. He also announced an ongoing effort by the company to reduce the cost of its hybrid drives by refining the system’s hydraulic accumulator.

California has another interesting funding option that offers significant opportunities. The Eaton Corp. (manufactures of the Hydraulic Launch Assist power system) is joining with the California Hybrid Truck and Bus Voucher Incentive Project (HVIP) to assist California-based fleets in purchasing low-emission, fuel-efficient medium- and heavy-duty hybrid vehicles.

The HVIP program was developed to speed up the introduction of hybrid trucks, and offers financial incentives ranging from $10,000 to $45,000 for eligible vehicles. Eaton is competing head to head with Parker, and the company has tallied more than 6,000 of its hybrid systems in use on buses, delivery trucks, recycling trucks, refuse vehicles and other commercial applications.

According to Corey Moore, global marketing leader for the commercial vehicles segment at Eaton, the HLA was the first step in saving fuel while reducing emissions and maintenance, but it’s not the last. “We have found that in the right application the HLA has a strong value proposition, but it requires a duty cycle that is just right, otherwise the payback can diminish,” Moore explains. “After two and a half years, we’re finding that we can offer a much lower investment and significantly quicker payback by addressing the onboard compaction handling hydraulics.”

Eaton’s solution is to replace the traditional fixed displacement gear and vane pump in standard power takeoff systems with a variable-displacement piston-type pump. Eaton calls the product “Power On-Demand” and it operates by using load-sensing valves and manifolds, so it consumes almost no power at idle, yet ramps up quickly to match the load that’s applied to the system. The design eliminates over-speed control valves, and it allows the packer mechanism to work at all engine speeds. Packing at idle is simple due to the POD’s ability to match engine power by utilizing constant torque controls.

The POD system has many applications, notes Scott Kanne, vice president of sales and marketing, Wayne Engineering, Cedar Falls, IA. Wayne Engineering designs and builds MSW collection vehicles, such as its Curbtender Auto Side Loader, first offered in the 1970s, and more recently, commercial-class front loaders and full-size rear loaders.

“Large refuse collection trucks benefit from the HLA system but they also benefit from POD technology,” says Kanne. “It’s one of those things that were really excited about and it works with front-end loaders or automated side loaders, and now we are finding that it can deliver the same or better results with rear end loaders. And the worse the route or driver behavior, the more effective the system, because it doesn’t allow the driver to abuse the truck.”

With the lower investment and quicker payback Eaton predicts that the market for its POD will be broad, but what about other benefits, such as oil changes and hydraulic maintenance? According to Robert Golin of Eaton’s Hydraulics Group, the traditional method of having the pump pushing hydraulic oil through the entire system regardless of whether it’s needed creates many problems. “Think of what that does to the system with heat and pressure and then during operations you get big spikes in his system,” says Golin. “It can cause premature failures, such as in the rear cylinder seals, valves, and an overall breakdown of the hydraulic system are all factors. Because this is a different kind of technology, we eliminate shocking the system with pressure spikes and the mechanical impact when a cylinder slams shut somewhere. With the older technology it happens thousands of times a day so it’s as hard on the system.”

Using the POD as something of an input location for assisting the engine is also the strategy behind the HEAD Hydraulic Hybrid Drive System, a product from Effenco Inc., of Montreal, Canada. But reclaimed braking energy provides the power. Although the HEAD System starts with the familiar method of storing kinetic braking energy for use in hydraulic pumps, it differs from other parallel systems, says, Simon Poulin, sales director. “We’re the only hybrid system that focuses on assisting the auxiliaries through the power takeoff unit. We have a hydraulic engine that is attached to the transmission with a direct link to the crankshaft, and it helps by powering the crankshaft turn and directly assisting the hydraulic pump for the auxiliary operations. If there is no auxiliary activity we could assist the engine with launching the vehicle.”

The HEAD system is designed for installation or retrofitting on any chassis, and the parallel configuration ensures that it won’t affect the truck’s reliability. After 2.5 years of testing with municipal and private haulers, with performance savings of 15% to 25%, Poulin says the company expects to have 50 of its systems on the road for 2013. New customers include the municipalities of Ottawa and Edmonton in Canada, plus some private haulers in Canada and the US.

Those customers can expect a 3.5- to 4-year payback on their investment, Poulin adds. And pilot programs with CNG hybrid vehicles in California show that fuel savings from the HEAD system can help to reduce the number of fueling stations required for a fleet of CNG trucks. Savings should increase in February 2013 when the company introduces a feature that shuts off a trucks engine when it’s stationary.

As the hybrid technology marketplace grows, Eaton and others also see a growing role for batteries. In August 2012, Eaton announced a $2.8 million project with the DOE Advanced Research Projects Agency, targeting battery size reductions and predictive performance management.

Batteries play a major role in the HybriDrive technology from BAE Systems, of Wayne, NJ. In mid-2011, BAE announced an agreement with refuse vehicle manufacturer Crane Carrier to integrate a heavy-duty hybrid electric propulsion system into one of its vehicles. The new parallel system is the latest member of BAE Systems HybriDrive family, and has its roots in the company’s HybriDrive series product, currently deployed in more than 3,500 transit buses across North America and Europe. The partners are targeting commercial launch in mid-2013 with production commencing in the fall for the 2014 model year.

“We’ve been developing this parallel system about three years now to meet the specific needs of the vocational truck market in refuse collection and pickup and delivery and construction vehicles,” says Mike Mekhiche, director of products and technology at BAE. “It’s scalable based on the vehicle’s size and duty cycle, and in our track testing through 16 duty cycles the performance demonstrated an average of 30% savings on fuel.”

The BAE strategy for scalability includes four transmissions and two sizes of electric generators rated at 70 kW with 400 m of torque, or 110 kW with 800 m of torque. “Then you have the battery storage system,” Mekhiche explains. “Because we want to make sure to leverage economies of scale for the refuse collectors that have the highest cost, we keep the components common. So a Class 6 vehicle could select a smaller transmission and the 70-kW machine. Or if it’s a Class 8 vehicle, by using the 110-kW generator with a larger transmission it could keep the same electronics and battery. So you get enhanced vehicle drivability and highest fuel economy possible for that vehicle with an optimized system that was scaled to the specific vehicle and duty cycle. At the same time you’re not losing anything in having to customize the electrical system and battery because those are common across all the vehicle classes.”

The weight and driving options are also key features. Says Mekhiche, “When you talk about our electric hybrid it has a weight of less than 400 kg, or around 800 pounds, versus hydraulic systems that can weigh 3,000 pounds. And it’s all done through electric wiring and not limited in terms of storage, because we have enough energy stored in the battery for the entire duty cycle. We’re seeing a payback of three years in some cases and no more than five years, so it’s an extremely attractive solution from the life cycle cost of maintenance and all the benefits of reduced emissions, fuel economy, noise pollution, and enhanced torque and acceleration.

With the battery’s reserve of storage energy and a clutch on both the engine side and transmission side, BAE’s system allows a driver to turn the engine off and drive the vehicle. “It’s quiet and can run for several hundred yards,” says Mekhiche. “The driver can also put the engine in idle mode where it’s running but quieter and consuming less fuel, then bring most of the power from the battery to operate with less noise than when the engine revs up and down.” In a refuse vehicle application the HybriDrive can support up to 15 mph between stops in a duty cycle without any impact. The battery is lithium-ion based, liquid cooled, and sealed. It’s mounted directly on the chassis of the truck to withstand shock and pollution.

The two clutches also allow the driver to operate the electric motor to power up to four power takeoff units. “We have the ability to electrify loads on the vehicle and use the battery for compacting and hydraulic power operations,” says Mekhiche. “We now expect to go to full-scale production by the end of 2014. It’s similar to what we’ve been doing with the bus business which is partnering with original equipment manufacturers that install our solution in their assembly lines for shipping to their customers.”

Progress in Europe and China
A hybrid system with a similar approach to the BAE philosophy is available to refuse vehicle operators in Europe. In May of 2009, Volvo partnered with Geesink Norba, a Netherlands-based manufacturer, to offer the UK’s first “plug-in” electric waste collection vehicle. The trucks use an electric motor to power the hydraulics for loading, compacting, and short-distance driving. Customers include the London and Paris divisions of Veolia Proprete.

In May 2011, Dow Kokam, France, put a totally electric refuse collection truck into operation in a Paris suburb. Dow Kokam develops and manufactures advanced battery solutions for the transportation, defense, industrial and medical industries. The 26-ton truck can travel up to 44 miles per hour fully loaded, and its lithium-ion batteries are rated at 250 kWh, enough to operate the truck through an eight-hour work shift. Dow Kokam’s large-format, flat-cell battery system offers a 10-year usable life and an energy density rating of 140 watt hours per kilogram of specific energy. The liquid-cooled lithium ion battery uses thermal management to extend the system’s lifetime and allows operations in diverse operating temperatures.

The project looks to be a step forward for all electric refuse vehicles in Paris, but if we step backward to 1914, we find that Paris officials put all-electric refuse trucks on the city’s streets, for much the same benefits as today. The vehicles featured front-wheel drive, with a separate motor for each wheel. The batteries sat in a compartment directly over the front wheels. Hydraulics were nonexistent, and the operator had to hand crank the tipping mechanism to empty the truck. Back in the US, Dow and the DOE’s Oak Ridge National Laboratory are working together to enhance the company’s capabilities to develop and commercialize advanced lithium-ion batteries.

In Beijing, China, where air quality and vehicle emissions are major issues, the Beijing Environment Sanitation Engineering Group recently launched a fleet of 1,060 all-electric refuse vehicles. The trucks were developed in China, and the majority are designed to cover up to 62 miles on a full charge.

As battery and drive-train technologies continue to evolve, could we see the balance of power lean more toward electrical systems with less of a reliance on fossil fuel power? In fact, the shift could be similar to what we’re seeing with the rapid growth of natural-gas technology.

Such companies as Dow and Eaton continue with aggressive battery research programs and strong support from the US DOE and other agencies. But it’s also a fact that the DOE is funding a $39 million program to increase the fuel economy of Class 8 vehicles by 50%.

The research is lead by Cummins, but includes such companies as, Peterbilt Motors Co., Bridgestone, and VanDyne Super Turbo. The initial target is long-haul over-the-road trucks, but engine efficiency is a major part of the research, and the results could well find their way to the refuse industry. So no matter the fuel, the industry’s future certainly looks to be one of higher mileage and lower emissions.

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