Once regarded as a fuel appropriate for firing boilers and power plants, natural gas has moved quickly to the fore as the fuel of choice for a newly arriving engine technology that delivers high-torque, heavy-duty performance.
Ray Burke, who was a manager of waste truck fleets for over 20 years, saw, firsthand, a decade-long metamorphosis of fueling opportunities that made it happen. It all began on a day in the mid-1990s, when the city of Palm Desert, CA, asked if his smoky, oily trucks of that era—which were daily plying their routes through pristine desert air—could possibly switch to something cleaner. Burke, then with Waste Management Inc., embraced the challenge—and thus became manager of the first trucks in the nation to try natural gas as a workhorse fuel for trash hauling.
Alas, things went rather badly. The first-generation engines and bodies arrived; Burke then promptly found himself the first of a number of case histories around the country, at that time, falling victim to wobbly prototype technology he remembers now as “undependable, underpowered” and lacking durability.
The earliest engine-makers scurried off in defeat—except for one, Cummins-Westport Inc. Cummins stayed, and continued struggling. Eventually, as Burke recalls, the Vancouver, B.C.–based firm was forced to rework its CNG-powered design through several generations.
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Photo: E-Z Pack
Fort Lauderdale's Choice Environmental operates 11 E-Z Pack NGVs |
Around 2003, he says, performance improved noticeably.
Then, in 2007 came the breakthrough “ISL G” model—a power plant “that really worked,” he says with real admiration. Today, after three full years of proving itself in many locales, “all the tech issues with the engine have been ironed out, and it’s been performing extremely well ever since,” he says.
Burke departed Waste Management to join Clean Energy Fuels (Seal Beach, CA), a firm that was positioning itself to service the phenomenal “next big thing” for the industry—CNG fueling of heavy-duty trucks—on a big scale.
This year, he forecasts, out of a total of 8,000 new trash trucks of all kinds that will likely be purchased, more than a quarter—2,500 or so—will be fueled with natural gas instead of diesel; he bases this on his own count of several large announced purchases. Before 2007, total annual sales for the natural-gas category “were maybe 300.”
As of late 2009, Clean Energy Fuels had signed its first trash fleet contract in Florida; this was subsequent to recent deals in New York, New Jersey, Washington, Colorado, and Idaho. Burke recounts: “In the last two years this thing has gone from, ‘Well, we don’t quite trust it, and body manufacturers don’t understand installing tanks,’ to the point that everybody is jumping back in.”
Clearly, something happened in 2007 to rocket the sales, in a few scant years, to a nearly tenfold surge.
That “something” was, single-handedly, the ISL G, he says. It’s now found inside no fewer than five trash truck makers’ product lines of refuse truck bodies. “Almost every company is looking at natural gas, for all the obvious reasons,” he notes. “It’s clean and domestic… Many regions are now starting to mandate it. Cities and lots of companies are making the transition—even small companies. If you talk to people who are actually using the trucks, they love them. They think they’re fabulous.”
Jeff Campbell, Cummins-Westport director of product marketing, is certainly enjoying the success and adulation. Since the new engine model came out, company sales have increase 50% each year, he says. Perhaps half of all the natural gas engines he’s producing are being put into refuse trucks. Already, about 10,000 of the nation’s total fleet of 170,000 trash trucks are fueled by natural gas, and—indicative of the epoch-making ISL G’s impact in itself—about 40% of these 10,000 are equipped with his new system.
Powerwise, at 9 liters, it produces 320-horsepower and 1,000 foot-pounds of torque, yielding, he says, “very diesel-like performance characteristics.” The previous model, at 8.3 liter, got 280 horsepower—“not quite big enough for many trucks,” he acknowledges, but the latest incremental boost has made all the difference.
On top of this, the ISL G’s use of a three-way catalyst, introduced three years ago, makes it the first EPA-certified 2010-compliant engine.
Now combine these developments with a serendipitous confluence of fuel price trends. In mid-2008, diesel prices shot up to new heights; shortly thereafter came the global downturn, and gas dropped to very appealing new lows.
And—as if this weren’t enough—federal legislation now contributes a magnanimous $32,000 incentive credit to every purchaser of engines powered with this “alternative” fuel.
Campbell loves the fruits of company persistence: “We’re pretty excited,” he says.
For its part, one of the biggest and most successful NGV trash truck body makers, McNeilus, assembles a typical line of front, rear, and side loaders, all with the new engine. Lately, McNeilus’ Jeff Swertfeger, director of marketing and communications, reports selling hundreds of them. Most notably, trash fleets for downtown Chicago are transitioning to CNG, he reports.
Mack Trucks Inc. last year introduced its TerraPro low-entry model refuse truck, also powered with the ISL G. Mack senior vice president of product portfolio management Tom Kelly anticipates that expenses will come out “comparable to diesel in terms of cost over the life of the vehicle.” Mack is also working with Volvo to develop a landfill-gas-fueled product that offers fuel production technology optimized for the landfill use, the company reports.
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Photo: Republic Services
Allied Waste at Boise, ID, is replacing its older diesels with NGVs. |
Operationally, these engines, with their eerily muted and smokeless characteristics—so out of character for trucks—are proving extremely popular with drivers and crews as well. Swertfeger observes that “Engines are so much quieter, it’s incomprehensible. You can’t believe it. Guys are starting to fight for the NGV units, because the work atmosphere is so clean and quiet. They love not getting pummeled with high-decibel engine roar and soot. It really is the slick nickel.”
Scott Edelbach, general manager for Vocational Energy, a truck fleet services provider in Tampa, FL, points out that natural gas is suddenly more desirable, vis-à-vis diesel, for another reason: As of 2010, the latter are burdened with carrying SCR pollution controls. These entail doing considerably more maintenance and carrying around an extra 30 gallons of diesel exhaust fluid, which freezes at 15°F—another issue with which to contend.
Gauging Tank Options
With such a radically different fuel on board, tank size, positioning, construction and numbers will each become critical factors to weigh. Selecting and implementing tank parameters will probably constitutes the most dramatic change, at least in truck body considerations, Swertfeger suggests.
Tanks and the attached routing pipes and hardware are typically either integrated right on the truck assembly line (as at McNeilus) or, quite often, are sent out to a third-party upfitter, he says. Either way, placement and attachment deserve attention. As “pressure vessels,” he says, they’re usually positioned, in a rear-loader truck, directly behind the cab “or up on the front of the body”; on front loaders, they’re almost always on top. Spacewise, “you don’t really lose anything” this way. But owners should take note of the added height and potential restrictions on usability.
On rear-loaders, tanks are usually mounted in front of and above the cab, “so it kind of gives the truck somewhat of a canopy look.”
Tank sizing, too, is a consideration. Comparatively, natural-gas systems suffer a 10% to 15% disadvantage on power output compared with diesel. So, additional volume—whether CNG or LNG—must be carried to achieve the same range. The usual conversion strategy seeks “diesel gallon equivalency,” or DGE. “We normally shoot for between 60 and 75 DGE,” Swertfeger says, meaning that sufficient tankage must be positioned somewhere onboard to get this.
Of course, installing tanks and pipes requires proper engineering, design, training, and quality control, adds David Myers, who is sales manager for Alt Fuel Products in Riverside, CA. His firm is the world’s largest manufacturer of carbon composite cylinders, marketed as the Luxfer brand. With improper workmanship, CNG, being gaseous, could be vulnerable to leakage, especially given the stresses of hauling over unpaved surfaces. For strength and lighter weight than steel, AFP’s Luxfer uses a seamless aluminum liner wrapped with carbon fiber and epoxy resin. The most popular size is 200 liters, which equates to 15 DGE; hence, “strapping four of them together on top of a cab gives you 60 DGE,” he says.
Some fleets need longer range, and with an extra tank get 75 DGE. Another option is the use of LNG with its increased energy-density.
AFP’s inventory includes 30 or so sizes, lengths, and diameters, to accommodate numerous designs, as efficient use of space is the prime consideration.
Regardless of the body manufacturer, all tanks are mounted either with straps that go around them, or by resting in aluminum blocks that hold them by the cylinder neck.
Total truck weight is also always a key number; GVW limits apply, and exceeding them can incur a citation and fine. Steel tanks and tubes are of heavier gauge; hence, the fleet owner may decide there’s an advantage in paying for lighter, composite materials.
Industry-standard pipes and fittings for gas should be made of stainless steel, rather than conventional steel, adds Mark Hurt, of SSP Fittings in Twinsburg, OH. “Natural gas has natural chemicals that erode carbon steel, and you get rust and things that cause problems,” he says. When shops do makeshift conversions from one fuel to the other, failure to use stainless steel is a common mistake, he finds.
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Photo: SSWR
Speciality Solid Waste & Recycling is operating NGVs in Sunnyvale, CA. |
LNG, CNG, and Engine Conversions
“The engine doesn’t care” which state the fuel is in, when stored,” notes Richard Kolodziej, president of NGVAmericva,
www.ngvamerica.org, the vehicle trade association. “By the time it gets to the firing cylinder, it’s vapor anyway. Some waste haulers prefer LNG for reasons of local availability or the greatly reduced stored volumes, increased payloads, and lower front-end costs.
Mark Hurt, whose company does CNG engine conversions for smaller vehicles, notes that LNG seems to be the storage-state of choice for trucks outputting 400 hp and above; below 250 horsepower, CNG is preferred; in between, it’s a tossup.
Skip Baker, president of Baker Equipment in Richmond, VA, also converts utility vehicles’ gasoline engines to run on CNG; he utilizes BAF Technologies’ Calcomp engine systems and Baytech Corp.’s CNG fuel injection systems, both of which are certified to meet current EPA and California standards.
Baker and Hurt each do engine conversions, which are quite commonplace with pickups and vans. Both men would like start doing trash trucks too—but the heavy-duty engines and emissions controls present a challenge.
Meanwhile, another conversion shop–Fyda Energy Solution Inc., of Pittsburgh—anticipates being the first to offer a retrofit conversion for popular Mack engines, a makeover enabling dual fueling, sometime this year.
FES president Paul Naman explains that, “Without hurting the engine, we will turn it into dual fuel to run on natural gas and/or diesel,” at a cost of about $50,000 maximum, depending on catalyzers and fuel tank configurations. The conversion itself consists of engine modifications, an injection system, electronic control nodules, and fuel tanks; it’s based on a system imported from Europe and used there for eight years now, he says. Conversions should qualify for a $25,000 federal alternative fuel grant program, and, thanks to fuel price advantages, total cost-recovery should arrive in 12 to 18 months.
On a contrasting note, though, speaking from his longstanding experience in New England, Michael Manning, director of marketing and business development for AVSG LP in Boston, considers engine conversions somewhat “iffy.” Having been involved with natural gas fleets since 1993, and as the former manager for Boston’s utility program for gas-fueled fleets, he says of conversions: “Possible—yes. But not so practical, operationally… The concept certainly will work. But most trash vehicles are pretty beat up,” and hence are not really worth the retrofit investment. He adds: “In my 17 years, I’ve seen the good, the bad, and the ugly in CNG fueling. If a fleet manager came to me and said, ‘We’d like to repower our vehicles,’ I would tell them, ‘Wait until it is time to do retirement of vehicles—and then do the transition.’” At which time: “Order new trucks, direct from the factory.”
All in all, he adds, “A transition to CNG or LNG is a quantum leap for most fleets It’s an incredible change for management of company for operations,” and to a lesser extent for customers.
How About Maintenance?
Besides the foregoing fueling/tankage issues, another novelty with gas is going to be spark plugs. Maintenance-wise, they add a dimension that diesels lack.
However, notes Cummins-Westport’s Campbell, comparative maintenance comes out pretty close anyway, both on cost and labor. “Service intervals are the same,” he says, “and both get the same warranty.”
Looking at the recent past, Scott Edelbach observes that, “Anecdotally, fleet managers are seeing a maintenance savings cost-per-hour on NGVs versus the 2007 [emission compliant] diesel engine,” already for the past several years.
At the 15,000-hour interval, a diesel “will show much more deposits and particles,” i.e., causing wear and added work., athough natural gas, “is 90% cleaner and wouldn’t leave much buildup and deposits,” he says. Hence, a costly engine overhaul could well be bypassed altogether. One fleet manager for a national trash-hauling firm reported to Edelbach that, out of 140 CNG trucks owned since 2000, only two needed major overhauls after a decade.
All in all, the more significant maintenance wild card these days is SCR, urea, and diesel particulate filters; none of these is needed on a natural-gas engine, but all are, as of 2010, on a diesel.
What About Cost?
As for comparative pricing, Manning suggests that a standard diesel vehicle priced $150,000 to $175,000, if outfitted with CNG options, will cost another $35,000 to $55,000. To justify the premium, some big advantage is necessary. Privately owned fleets can reap the above-noted $32,000 federal tax credit—a magnanimous sum he rightly calls “incredible.” However, city fleets don’t need tax breaks. Hence, three-way deals will likely be arranged between OEMs, vendors, and municipalities, to enable swapping of this credit.
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Photo: SWACO
This natural gas-powered vehicle is ready for action. |
Operationally, the cost of both fuels works out historically pretty close. But looking forward, the prospects for much cheaper natural gas are rosier than ever, thanks to the Marcellus shale deposits, located underground in much of the Northeast.
Manning observes: “In my 17 years in the natural-gas industry, I have never seen the supply of natural gas in the US so positive. A phenomenal amount of gas will be coming to market—as much as a 75-100-year supply,” he says.
And it’s likely to stay below $6 per million Btus for some time, compared to much higher prices throughout the past decade.
Even better, multiple tax breaks are coming due for passage in 2010; they’ll likely push net natural gas cost lower, through 2027. (See H.R. 1835.)
Increased Options
Royal Disposal and Recycling, headquartered in Fulshear, TX, just outside of Houston, purchased four CNG-powered rear loaders from McNeilus in recognition of a recent situation affecting operations. Co-owner Charles Gregory remembered the difficulty in finding diesel fuel during Hurricane Ike and vowed the refineries would never again hold him captive.
“When the hurricane hit, the refineries shut down, and it made it very difficult to maintain operation. We were pretty much on our own and we made the decision then and there that we would reduce our dependence on both our refineries and foreign oil,” say Gregory. Longer intervals between oil changes, the dramatic reduction in noise, and the huge savings in fuel cost were additional factors that played into the decision, Gregory says.
In sum: Now, more than ever, natural gas looks like the truck fuel for America’s future.
Making the Transition
Two years ago Chris Martin was president of a one-truck operation called CleanScapes of Seattle; a year later he was launching 75 clean, new, aesthetically eye-catching CNG vehicles across the city, after winning the trash contract of a lifetime. The deal didn’t hinge on buying CNG-fueled trucks, but that certainly helped, he says. In any case, Martin and Seattle have now accomplished “the largest CNG transition in the country” to date, he’s been told.
In selecting what to buy, Martin looked over potential OEM components available à la carte, from which one can, in effect, design and build a composite on a platform, not unlike picking toppings for a pizza: “First the chassis and engine, then the body gets put on, then fuel tanks.” But after further review he thought better. “Okay, now there’s three people to point fingers at each other, instead of one party.” That’s not so good.
Conversely, buying a preintegrated package from one vendor meant “everything was engineered to work together… right out of the factory.” He liked that much better, so opted for what turns out to be virtually the only mated chassis and fueling system in this particular niche, anywhere. It’s from Crane Carrier in Tulsa, OK, on which is mounted a body from waste-truck industry-leader McNeilus.
Size-wise, Martin picked smaller, more nimble trucks, suitable for tight Seattle neighborhood streets. Travel distances to the city’s outlying transfer stations is a mere 15 minutes, so bodies don’t need to haul so much tonnage. Staying compact also saved onboard weight, allowing room for welding on the largest integrated CNG tank option offered.
Why do this?
“Just to ensure that we had two days’ worth of fuel on the trucks,” Martin replies. This precaution seemed wise to him, in the eventuality that fuel supplies might ever be interrupted, as could happen for any number of reasons. With huge storage capacity on board, he’d have a second full day’s worth of gas as backup.
As for the fueling station, which was built by Clean Energy: it has suffered virtually zero downtime to date and works continuously, 24/7.
One final and major factor to weigh carefully, Martin advises, is the need to retrofit maintenance bays: by converting to CNG from diesel, “You introduce a whole new building code requirement,” necessitating things like “gas detection alarms, explosion-proof lighting and fans, and automatic venting systems that kick on to vent that gas.” These, he adds, are not necessarily cheap. However, purchase of each truck was nicely offset by $40,000 worth of tax credits.
A contrasting approach was taken by the city of Lake Jackson, TX, a fairly early CNG adopter, notes director of public works Craig Nisbett.
The change-over began a decade ago, with 20 light-duty pickups converted; in 2002 the department added garbage trucks; as of 2010 the last diesel has been retired, and now Nisbett’s fleet of 15 is all-gaseous.
Mechanical problems did come up at first, but were traceable to an odd batch of solenoid valves. After replacement, things went fine, and every original truck is still running daily service for the city, says Nisbett.
His latest, bought in 2010, is a Heil packer body, mounted on an Autocar frame with the department’s now-standard Cummins-Westport engine for power.
Nisbett says he’s been extremely pleased with Heil’s 25-cubic-yard rear-load packers, mainly for crunching at a higher compaction-rate than the previous type he had (a now defunct brand). Daily routes weren’t being finished, he says, “so in the middle of the day we would have to go to the landfill and dump and come back and finish the route—which basically is an hour turnaround time every time.” Running back-and-forth so much, “you’re killing your vehicle time, and you also have a driver to pay,” he says.
But with the Heil’s bigger muscle, “generally speaking, we make it all the way through the day’s route and just dump at the end of the day.”
In switching to Heils (which are, he concedes, pricier) compaction wasn’t the only consideration, but when it came time to cost-justify them to the budgeters, “I think that’s what put us over the hump,” along with the brand’s reputation for being sturdy, well built, “and able to last a while. We had always wanted the Heils,” he says, but frugality ruled. “Now though, I think we’re a little more long-sighted on purchasing.” Since purchasing his first, he’s acquired six more, including a shiny new one in 2010.
Other purchases over the years include multiple Crane Carrier chassis with some John Deere and some Cummins engines, and some Macks. The latter run heavier commercial trash routes, and the Autocar Crane Carriers power the residential runs.
This motley parade of mixed chassis and bodies didn’t come about so much by conscious game plan, he says, but as a reflection of the industry’s consolidations and morphing of brands.
As for tankage decisions, here, he says, you should first calculate carefully “how many gallons of fuel do you need, and work with your supplier on where are you going to stick it on the chassis.”
He’s not saying his department erred, but he suspects that “people tend to overestimate the amount of fuel they should carry—and there’s a cost for doing that. So, don’t spec more fuel on board than you need.”
All in all, the ownership experience has been entirely positive, and nothing negative. “Drivers like them because they’re quieter, and supervisors like them because they fuel overnight and you don’t have to queue up at diesel pumps,” i.e., wasting the time of people who are on the clock.
Costwise, Nisbett’s experience was rather different from Martin’s in Seattle: Being a public agency, a write-off for him is useless—but he’d love to learn how it’s done by others. “Despite what anybody says,” he concludes, “our experience is you’re going to pay $50,000 extra for a CNG garbage truck.”