Coming of Age

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Hybrid trucks were coming on strong, very strong, this time last year, as the 2008 rendition of the Work Truck Show demonstrated.

There were vendors aplenty and an upbeat mood in the air. Everyone knew that commercialization of this once exotic technology was just around the corner.

And even last October, the annual national meeting of the Hybrid Truck Users Forum in South Bend, Indiana, was a wildly successful affair that some 550 people attended. The hybrid truck looked like a real player, with momentum behind it.

"We’re so close to the tipping point, to commercial success, but we’re not there yet," said John Boesel, president and CEO of
CALSTART, in his opening address to that meeting last fall.

The HTUF event is organized by CALSTART, which is a California-based non-profit organization that works to develop and implement clean, efficient transportation options, working with manufacturers and end users alike. HTUF is an offshoot, a user-focused coalition, North American in scope, that aims to speed the commercialization of hybrid trucks.

Boesel said the hybrid industry would be well established when 2000 to 3000 trucks a year are built. He envisioned a 30 percent hybrid share of the work-truck market and 5 percent of the heavy-duty market by 2020.

Things have slowed down a bit in the intervening months — chopped budgets have slowed the pace of sales, and low diesel prices have extended payback periods, making the switch to hybrid less appealing — but one research outfit sees good things coming soon. 

Kenworth’s largest-ever hybrid truck order
will put 185 diesel/electric and hybrid tractors
in the Coca-Cola Enterprises fleet this year

In a report on the commercial vehicle hybrid industry, NextGen Research of Oyster Bay, N.Y. says the global commercial hybrid vehicle market will triple from 8,653 units in 2008 to more than 27,000 in 2013. The study says the market will begin to grow more quickly in 2010, as the ­global economic downturn ends and the testing of hybrid vehicles in commercial fleets is completed.


Not long ago it was FedEx and UPS that led the hybrid way, but nowadays there’s equally serious activity at outfits like Wal-Mart  Coca Cola, and the U.S. military. The latter has been much involved with CALSTART and appears to be Mack’s main hybrid customer. The truck-maker recently delivered its first diesel-electric hybrid refuse truck to the US Air Force (USAF). The TerraPro low-entry truck is the fifth hybrid that Mack has built for them, the rest already in operation around the country.

This one has a rear-loading refuse packer body and a 325-hp MP7 engine. Its Mack hybrid electric powertrain features an integrated starter, alternator and motor that assists the MP7 in providing torque to the wheels. Using regenerative braking, the conceptual cornerstone of the hybrid idea at large, braking energy is captured and stored in lithium-ion batteries. The system is expected to improve fuel economy by 20-30 percent while reducing maintenance costs.

In a different world, late last year UPS announced the order of seven hydraulic hybrid vehicles, in the form of the ­traditional brown UPS curbside van. Using an Environmental Protection Agency patent for the hydraulics, the trucks are the result of a partnership between UPS, EPA, Navistar, which supplies the chassis, and Eaton, which supplies the powertrain. The first two are in service in Minneapolis now.

It’s a ‘series’ hydraulic hybrid in which a small but efficient diesel engine is combined with a hydraulic propulsion system, replacing the conventional drivetrain and transmission. Hydraulic pumps and storage tanks capture and store braking energy, as with a diesel/electric hybrid. But in this case, the diesel is used to periodically recharge hydraulic pressure and can thus be run at a very efficient steady rpm. It can also be shut off when stopped or decelerating.

The guess is an upcharge of about $7,000, but tests of a prototype in Detroit for the last 18 months show spectacular fuel savings of 40-50 percent, fully 60 ­percent in the lab. Emissions show a reduction of 30-50 percent. The advantage of the hydraulic answer compared to electric is a matter of simpler technology in general, with no complex electronics to develop and then manage.

"There’s no question that hydraulic hybrids, although little known to the public, are ready for prime time use on the streets of America," says David Abney, UPS’s chief operating officer. "We’re not declaring hydraulic hybrids a panacea for our energy woes, but this technology certainly is as promising as anything we’ve seen to date."

And Coca Cola Enterprises (CCE) plans to deploy another 185 hybrid electric trucks across the United States and Canada this year. When they’re all on the road, the fleet will have 327 diesel/electric delivery trucks, the largest such fleet in North America. It has 142 hybrids running now. This new order is for 150 Kenworth T370 diesel-electric tractors, CCE’s standard bulk delivery unit, and 35 T370 hybrid straight trucks. The hybrid tractor is said to use about 30 percent less fuel and produce some 30 percent fewer emissions than standard tractors. It uses electric power at speeds below 30 km/h.

Wal-Mart’s fleet now has this International in the fleet,
sporting ArvinMeritor’s first hybrid electric powertrain.

Perhaps the most aggressive fleet in terms of testing better-than-diesel power options is Wal-Mart’s transportation arm, which runs nearly 7200 heavy-duty trucks in North America. It managed a whopping 25 percent increase in efficiency between 2005 and 2008, surpassing one of its stated sustainability goals. The company aims to double fleet efficiency by 2015, from a 2005 baseline. Hybrids are part of this effort, along with biofuel and natural gas, but also more intelligently designed delivery routes and more efficient trailer loading.

Its most recent test acquisition is an interesting one, namely a full-propulsion ArvinMeritor hybrid system in an International ProStar that will initially operate in Detroit. This dual-mode diesel-electric hybrid is said to be the first vehicle of its type, and its the first Meritor diesel-electric drivetrain

"While most hybrid systems today are best suited for start-stop applications, our hybrid drivetrain is specifically designed for linehaul, over-the-road trucks, the largest segment of the commercial vehicle population," says Carsten J. Reinhardt, president of ArvinMeritor’s Commercial Vehicle Systems business.

The dual-mode hybrid drivetrain combines both mechanical and electrical power. Under 48 mph, or 77 km/h, the truck is powered entirely by an electric motor and a bank of lithium-ion batteries, which are recharged through regenerative braking and/or an engine-driven generator. As the tractor hits highway speed, the drivetrain phases to diesel power, using the electric motor only as required.

The key differentiation of this system, says ArvinMeritor, is its ability to run in zero-emissions mode in a wide range of situations, allowing the truck to operate in places where emissions are restricted, like a port or urban area. The batteries also provide continuous power for hotel loads during an overnight rest period, eliminating the need for engine idling or other anti-idling systems. Electrification of accessories such as the air and AC compressors offers further efficiency benefits.

The Meritor hybrid drivetrain was developed in collaboration with Navistar and Cummins and consists of a proprietary motor/generator unit with high-capacity lithium-ion batteries, as well as the overall power-management system.

Peterbilt is also very active with Wal-Mart, and it’s in the process of delivering five Model 386 tractors with diesel-electric hybrid power systems developed by Eaton and PACCAR.


Given the cost of entry, serious explorations in hybrid technology have been mostly a big-fleet playground. And American at that. But there’s one interesting exception in Victoria, B.C., where R&B has what’s being called the cleanest refrigerated delivery truck on the continent. The company, run by Paul Cunnington, is a delivery agent for Clark Freightways. It has 28 trucks on the road, this one being the only diesel/electric hybrid.

Cunnington’s class 7 Freightliner M2e 106 straight truck uses a small Cummins engine and the Eaton hybrid system. It also has an interesting electric refrigeration unit powered by the hybrid system, eliminating the need for a second diesel engine. It should save as much as 35 ­percent in fuel costs and reduce greenhouse gas emissions by more than 20 tonnes a year.

That all-electric reefer unit is made by Aura Systems of California , which is predominantly a maker of mobile-power electric generators for military use. More recently involved in truck refrigeration after the acquisition of Global Refrigeration, it makes the ‘Oasis’ midrange truck unit as seen on the R&B vehicle. Intended to run electrically off a PTO-driven generator, it was modified in this case to get power from the hybrid system. And it probably has a big future in either form.

Introduced last September, with capacities of 15,000-20,000 BTU/hr, it’s on the road in more than 100 trucks so far. Aura says Penske, Ryder, Idealease, and smaller regional leasing companies have agreed to provide a leasing option for this system for select customers. Coming noise and emission regulations will very likely make this sort of product very popular. Aura conservatively estimates shipping over 700 systems in 2009 and 2000-plus in 2010. It will also introduce a trailer system in the first half of this year.

R&B Trucking notwithstanding, it’s likely that we’ll have to depend on large companies such as Coca-Cola and Wal-Mart to advance the hybrid truck commercialization process for now. They’re hurting too, of course, but they have deep pockets. Enviable, eh?

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Rolf Lockwood is editor emeritus of Today's Trucking and a regular contributor to

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