Fuel for thought: The latest innovations in CNG fueling systems for collection vehicles
Eight years ago, with fuel prices as a driving factor, the WCA Waste Corporation began transitioning its fleet to CNG. “For those like myself who were early adopters, there were some struggle years,” says Jason Saunders, WCA’s vice president of fleet and procurement.
His advice to solid waste operations today: “It’s a great time to contemplate CNG.”
The company has transitioned 16% of its fleet to CNG. Industry experts observe a broad rate of adoption, based on innovations in everything from CNG trucks to fueling and maintenance.
Bill Zobel, vice president for market development and strategy at Trillium CNG, notes that the value proposition of the fuel is largely driven by its low cost and its consistent pricing.
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“Compressed natural gas, especially in today’s market, is a lot less than traditional petroleum fuels in terms of cost at the pump as primarily driven by the fact that it’s not a petroleum-based product,” says Zobel.
“It’s not tied to the price of oil,” he adds. “Rather, it’s tied to the US natural gas markets which should provide very stable pricing and if you forecast that forward, they’re expected to be very stable for the foreseeable future. That presents fleets that are looking for some kind of price certainty and less volatility in their fuel pricing [with a] real opportunity to move over to the fuel.”
Innovations are occurring with CNG vehicles and fueling infrastructure, Zobel points out.
Case in point: the recently-introduced Cummins Westport ISX12 G for natural gas—which is 90% lower in its emissions profile than any petroleum fuel diesel engine with which it would compete within the marketplace, remarks Zobel.
It is a clean alternative for refuse operators who operate in tight urban environments in concentrated neighborhoods with some air quality concerns, he adds.
WCA started transitioning to CNG at its urban environments in Florida and Houston. While the trucks serving the company’s more rural locations are still predominantly diesel, WCA is committed to replacing 10% of its fleet per year, says Saunders.
“Not only is it cheaper even when diesel is at its lowest, but it’s also much more stable and much more predictable than diesel, so it’s easy to forecast your infrastructure costs,” he adds.
A mid-sized Houston-based solid waste management company, WCA serves eight states, primarily in the south. It has 3,000 employees, a half-billion in annual revenues, 30 hauling companies, 14 landfills, and a fleet of 1,000 trucks.
While there are “pretty significant investment” costs in installing onsite fueling for CNG, the return on investment is realized in the reduction of fueling time, says Saunders.
“Our drivers simply park the trucks, plug in, and it will slowly fuel their trucks overnight,” he says of the fueling stations.
Saunders says his operation is also finding that “maintenance costs long-term on a CNG truck versus diesel have flip-flopped where CNG is more desirable from a cost per operating hour and a cost per maintenance hour.”
WCA has converted to CNG by acquiring both new trucks or competitors, says Saunders, adding, “it’s typically not cost-effective to do retrofits unless it’s in the long-haul trucking aspects.”
WCA mitigated the infrastructure costs by applying for state incentives through Texas or Florida “when we really didn’t know the long-term benefits of CNG versus diesel,” says Saunders.
“Most people got into the market as we did as early adopters based on incentives through the state,” he adds. “Longer term, as we discovered that CNG does pencil out two to three years down the road, we were able to say without state incentives in the current marketplaces where CNG is available and where we’ve got sizable fleets, it’s still worth making the investment.
“It may not pencil out until four years down the road versus two or three with incentives, but ultimately, most of our trucks are on a 10- to 12-year replacement life cycle, so the upfront additional infrastructure costs still balance positively for us.”
WCA has partnered with Autocar for all of its chassis and with Heil body manufacturing. The company also has relationships with Cummins, its CNG engine manufacturer, and Momentum Fuel Technologies as the provider of the CNG onboard storage systems.
Jim Elias, director of energy services for the quasar energy group, notes that gas is depressurized when loaded into CNG trailer tanks (maximum at 3200 psi shutoff) and then re-pressurized when offloaded at an existing CNG fueling station. A trailer is filled with the equivalent of 1,000 gallons of gasoline a day.
Biogas utilized as transportation fuel such as CNG has significantly higher revenue potential than biogas utilized for offsetting natural gas expenses for boiler or pump engine fuel, notes Dave Baran, director of project development, quasar energy group.
FirmGreen develops and commercializes technologies to process waste products into vehicle fuels and alternative energy.
The company’s technology converts solid, liquid, and gaseous hydrocarbons from available renewable resources such as landfill gas, wastewater, and biomass into electricity and clean biofuels.
Steven Wilburn, president and CEO, says the company upgrades the biogas to the equivalent of pipeline quality natural gas “and from there, we can go to compressed natural gas by adding compression stations, we can inject it into a pipeline to be distributed to CNG stations as renewable fuel, or we can further upgrade the methane and reform it into hydrogen fuel.”
Wilburn points out that the inherent innovations in CNG in the solid waste industry focus on the two forms of biogas that are available from organic waste material that’s deposited either in the landfill or into an anaerobic digestion process.
Landfills have represented more legacy in the application of technologies such as that of FirmGreen’s in upgrading the biogas from landfills into CNG.
Autocar manufactures heavy-duty CNG trucks for the solid waste collection market. The company approaches the trucks as an integrated solution of a truck, engine, fuel storage tank, and fuel management module, notes Marc de Smidt, vice president of ATX Refuse Engineering for Autocar, adding that the company relies on a few other companies to provide input.
Autocar installs diagnostic and fuel management modules in each truck to enable operators to monitor engine performance and gas usage.
Some CNG suppliers have recently moved from analog to digital systems with a built-in controller, says de Smidt, adding that the company provides special electric connectors with defined pins to hook up either system without necessitating splicing or wiring. An interface is provided on the J1939.
Autocar also provides a complete kit to any fuel management module supplier to do a direct bolt up and connect up to its system, says de Smidt, adding that the trucks’ current display is programmable for analog or digital for a multitude of suppliers.
“The system will automatically detect and configure to display their fuel gauge levels and range to zero,” he adds.
The approach addresses one of the prime barriers to entry, which is “making provisions in your software
for multiple different methods of transferring information into the truck,” says de Smidt.
Adam Burck, vice president, brand management for GVW Group, points out that there’s been a significant volatility in diesel prices in the past year, with diesel up 54% while CNG prices are effectively flat.
“It is disruptive to haulers using diesel and if they’re able to switch to CNG, there are substantial benefits to them for many reasons,” he says.
On the other hand, switching to CNG “can be challenging,” says Burck.
“There are not only changes in the trucks but in the fuel supply, the maintenance facilities, and the training,” he says, adding that Autocar endeavors to help end-users through the process of switching to CNG.
That includes helping end-users install their own CNG plant, produce their own CNG from landfill gas or use a local source of CNG “because they can often get the trucks faster and evolve to their own fueling location,” says Burck. “If you don’t have CNG fueling facilities already in your area, it can be tricky.”
Using landfill gas directly to power trucks has a few inherent challenges, says de Smidt.
“There are specific cleanliness levels required for gas engines in terms of the cleanliness of the gas and pollutants that may or may not be used in these trucks,” he says. “A facility with commercially available gas has those cleanliness labels under control whereas, with landfill gas, you need special scrubbing and cleaning of those gases.”
Louis-Charles Lefebvre, regional sales manager for Eastern Canada and international sales manager for Labrie, says the company offers customized solutions in that a CNG tank can be mounted nearly anywhere on a truck: backup cabs, roof models, frame rail mounts, and tailgate mounts.
The company can create solutions ranging from a small capacity to large capacity to run a truck for 14 hours without any problem, says Lefebvre.
The company also uses Type 3 cylinders for their resistance to cold weather and a front of the body deflector that prevents branches knocking on the CNG tanks, he adds.
While the expense involved in CNG is in a solid waste operation building its own station, “the ROI on the kits you install on a truck is probably three to four years, depending on how much you’re burning and the price of oil,” says Lefebvre.
Companies such as Omnitek help CNG end-users adopt vehicles to accept the fuel. Omnitek converts heavy-duty diesel engines to natural gas engines and builds new natural gas engines and generators.
Thus, the company can convert truck engines as well as compact equipment and generators used at landfills.
“The owners of the vehicles don’t have to buy completely new vehicles because the lifespan of these engines is so long,” notes Werner Funk, the president and CEO of Omnitek. “It makes sense to convert rather than to buy a new vehicle.
“It’s more or less like an engine overhaul. The engine gets completely rebuilt with new pistons, new valves and everything and the diesel components are replaced with our engine management system components.”
The process takes between 7 to 10 days per engine, Funk adds.
Omnitek converted several Waste Management solid waste trucks in San Diego, CA, a few years ago.
Funk points out that the operation has its own fueling infrastructure in the yard, something that’s necessary in order to operate a CNG fleet. Another converted fleet in Virginia also has its own infrastructure.
“If you don’t have that infrastructure in place, you have to have a gas station that’s large enough where you can drive in with a truck like that and not all CNG stations have that capability,” he says.
Energy security is one of the prime reasons solid waste fleets are converting to CNG, notes Funk.
“There’s always been the thought we should move away from diesel or petroleum-based energy sources and since the US has so much natural gas, using the natural gas helps with the larger policy of energy independence and energy security,” he adds.
“Sometimes companies like Waste Management have access to liquefied natural gas (LNG) that is made from the methane that comes off the landfill. That makes the fuel pretty inexpensive to a company that has that capability.”
Fuel management technology continues to improve in the marketplace, says Kyle Edington, Worthington Industries’ marketing manager for alternative fuels.
“Worthington has focused on improving the distance a natural gas vehicle can travel and reduce downtime for CNG fleets associated with preventative maintenance functions,” he adds.
Its cylinders feature fiberglass overwrap.
“The addition of a semi-transparent sacrificial layer made of fiberglass increases the speed of cylinder inspection,” says Edington. “Fiberglass has traditionally been used in the transit bus markets but only recently been introduced to the refuse market. The additional layer reduces the amount of time needed to inspect CNG fuel systems.”
With respect to fuel management, the company’s new top of body fuel system features redesigned, simplified plumbing designed to optimize gas flow for better performance.
“Matched with Worthington’s fuel management module, the fuel system will maintain proper pressure to the regulator at 200 psi,” says Edington.
The industry is evolving in the refueling space, says Zobel.
“When the solid waste industry first converted their fleets over to natural gas fuel, they were working on the largest facilities first—collection facilities with 70 to 150 trucks. Years ago, the equipment we were using on the refueling side for the large facilities wasn’t a great fit for the smaller operator with 10 to 20 trucks. It was just too expensive.”
Now small fleets that want to move over to natural gas “have a very cost-effective solution on the refueling infrastructure side to meet those needs,” says Zobel.
Because solid waste trucks can time fill, they can use smaller systems without the requirement for the same capacity, he adds.
Trillium has been able to package up smaller compressors available on the global market that typically weren’t very common in the US to work for smaller fleets, meeting an end-user demand, Zobel says.
“From a cost basis, it reduces the cost of just the compression component 30 to 50 percent over what would have been a traditional system three to four years ago,” he adds.
As CNG systems evolve and there is a broad rate of adoption, one of the few barriers left is resistance to change, notes Zobel.
“Diesel is the fuel folks are comfortable with. They understand how it works,” he says. “What I think folks struggle with most is understanding what it takes to move traditional fuel over to an alternative fuel like natural gas.”
Clean Energy provides vehicle fuel turnkey services, including designing, engineering, building, operating, and maintaining CNG and LNG fueling stations for heavy-duty applications including solid waste collection vehicles.
Solid waste vehicles are a good fit for CNG because they are a return to the base fleet, notes Mike Cecere, East Coast regional manager for Clean Energy. The majority of stations Clean Energy constructs for its end-users are time fill stations.
“There is a lot of downtime on a garbage truck, so we take advantage of that,” says Cecere, adding that diesel-fueled trucks pull into a yard at the end of the day and sit in a queue for hours as individual trucks fuel up before parking.
CNG time-fill stations eliminate that, he adds.
“At the end of the day, the drivers park their truck in their spot, hook up a hose to the front of the truck, and walk away,” says Cecere. “We set the compressor to kick on during off-peak hours so it cuts electricity costs in half. It reduces operating costs and overtime expenses as all of the trucks fuel up at the same time.”
Depending on the fleet and the size of the compressors, an entire fleet can fuel up from four to eight hours, says Cecere.
Cecere notes that any solid waste operation fleet of at least 20 trucks can justify building its own fueling station onsite.
“They are burning enough fuel to get the ROI not only on the truck side but on the station side as well,” he says, adding that current oil prices means solid waste collection operations using CNG are cutting fuel savings in half.
Cecere also says CNG-fueled vehicles are easier to maintain because they don’t have the particulate traps, filters, or urea as found in diesel-fueled vehicles. Nor do drivers have to mitigate a regeneration light when it activates on a diesel vehicle dashboard, he adds.
ET Environmental is a general contractor that provides design-build work for the solid waste industry.
While in general, CNG parts haven’t changed significantly over the past few years, there have been some continual incremental improvements on the controls and communications pieces, says Steve Arnold, vice president of engineering for
“There are requirements because of the lighter than air fuel that we need to make sure that there are no emission hazards and that there is a proper alarm system installed in these garages,” says Arnold.
ET Environmental also is engaged in value engineering, examining the reliability of the systems by using ventilation systems and gas detection alarm systems.
“The alarm systems are more sophisticated now than they have been in past years in the way they communicate and in their remote visibility,” says Arnold. “They can be monitored remotely for both functionality and for alarm conditions.”
That mitigates a challenge from the past in that if there had been a malfunction, it may not have been corrected for lack of that realization, says Arnold.
For those operations seeking to make the switch, the first step for a waste operation is to ensure the customer is going to be comfortable with the fuel, says Zobel.
“In most cases, these folks pass through their fuel costs to the municipality they serve. They want to make sure that they’re still able to do that,” he adds.
The next step is to evaluate the replacement cycle for a fleet’s vehicles.
“You want to see at what point in the cycle you’re going to be able to start transitioning these vehicles from traditional fuel to alternative fuel and what that transition cycle might look like,” says Zobel, adding that many fleets will transfer large numbers of vehicles simultaneously.
Then, a solid waste operation needs to ensure there is a fueling scenario that serves the needs of the fleet.
“If you’re a smaller refuse operator looking to convert three to four trucks a year over the next 10 years, then you’re probably not going to have enough critical mass to build your own onsite time-filled system for several years,” says Zobel.
“You don’t have enough fuel to justify the cost of that infrastructure in the short term. So short term, if you can use a public access network or a facility like a Trillium facility close to your operation, then you can fuel there in the short term until such a point that you hit critical mass and you can put in the facility for yourself and capture those economic benefits.”
Zobel says more than half of the country’s states have adopted a 2,000-pound weight exemption for alternative fuel vehicles.
“One of the concerns about moving over to natural gas is the weight of the fuel system that’s on board the truck,” he says. “Natural gas trucks use large composite cylinders and a valving system to store the fuel on the truck and compared to a diesel tank has an incremental weight penalty about 1,000 to 1,500 pounds. It’s called a weight penalty because it takes off the amount of cargo of paid freight that you can put on that vehicle.”
The weight exemptions that have been passed by the states allow refuse collection vehicles a weight level of up to 82,000 pounds, with enforcement varying by state, says Zobel.
This article originally appeared in MSW Management Magazine, February 2019