Cases Made For CNG As An Alternative Fuel

Fleet managers, no matter the industry or size of fleet, generally have a long list of priorities and concerns that keep them fully engaged in their work. While not necessarily the top priority (or concern), the costs associated with keeping any type of fleet fueled is certainly something that gets a lot of attention, and rightly so.

In the United States, where cheap oil and gasoline prices have been the norm the last few years, the pressure on fleet managers to find alternative fuel sources has lessened a bit. However, fuel prices are very cyclical, so many fleet professionals are also looking ahead to see what other options might exist. Given this, a growing market exists today for vehicles powered by alternative fuels, including compressed natural gas.

CNG is made possible by compressing natural gas to less than one percent of its standard atmospheric pressure. The result is an odorless, colorless, and tasteless fuel consisting mostly of methane, but one that burns more efficiently and cleanly than either gasoline or diesel.

Incentives play a role

CNG-powered service vehicles, in particular, are currently being used by an increasing number of private sector and government entities, especially in locales where special vehicle fuel systems are required and/or incentivized. One of the reasons for this is the potential cost savings CNG fuel systems can offer.

For example, CNG Now, an industry-sponsored educational Web portal (www.cngnow.com), says CNG costs about 50 percent less than gasoline or diesel fuel, and produces up to 90 percent fewer emissions than gasoline. So the cost savings and decrease in pollutants emitted over the long-term can be substantial, especially for entities with large vehicle fleets.

According to CNG Now, the history of natural gas as a transportation fuel actually dates back to the Second World War, though natural gas vehicles now feature safer, more reliable systems. More than 12 million CNG-powered vehicles are now on the road worldwide, but only about 250,000 of them are in the United States. Nonetheless, the U.S. has experienced an average growth rate of 3.7 percent in CNG-powered vehicles per year since 2000, though this pales in comparison to the global growth rate of 30.6 percent per year over the same time period.

One entity that has benefitted directly from this growth is the City of Kansas City, Mo., which has been investing in an alternative fuel program for nearly 20 years in response to concerns regarding local air pollution. Today, the city uses approximately 620,000 gallons of CNG annually, which accounts for 26 percent of the total fuel used.

Bigger fleets more likely to benefit

“We currently have 235 CNG vehicles spread across many departments,” says Samuel Swearngin, fleet administrator for the City of Kansas City’s Fleet Services Division. “In the early days we had more light duty CNG vehicles, now we focus more on heavy-duty trucks.”

Swearngin says the best results have come from using CNG to power dump trucks and other large utility trucks, as these larger vehicles can accommodate the CNG fuel tank package without much impact on overall performance. He points out that CNG tanks are bigger and heavier, so for truck applications the frames have to be stretched a couple of feet to make room. These larger fuel tanks are a downside, Swearngin admits, but it’s not enough to outweigh the cost savings he believes are associated with using CNG.

“CNG fuel is much cheaper and cleaner than gasoline and diesel; and the new heavy duty CNG truck engines perform better than diesel for the type of driving we have in municipal applications,” says Swearngin, who notes that his department outsources the CNG fueling component, so there is no on-going station maintenance.

But in an environment where government budgets are stretched thin, how has Kansas City been able to invest in this technology and build-up such a large CNG-powered fleet?

“Historically, CNG has been a third of the cost of conventional liquid fuels,” explains Swearngin, who says the city plans to purchase more CNG heavy-duty trucks. “In the best application, CNG trucks will have an ROI (return on investment) in about two years, while other applications take longer. The more the truck is used, the faster the ROI.”

Need for extra tank space a factor

Despite the potential fuel-cost savings, other things must be taken into account before switching a fleet over to CNG. For example, there might be costs associated with regulation compliance (like gross vehicle weights), as well as space cost trade-offs given the need for larger vehicles — both of which are issues for a truck up-fitter, like Illinois-based Knapheide Manufacturing Company in Quincy, which frequently deals with servicing customers interested in acquiring CNG-powered vehicles.

“CNG tanks need a lot more space, so the cost of a CNG system is very dependent on the size and number of tanks,” says Chris Weiss, vice-president of engineering at Knapheide (www.knapheide.com), which is a certified installer for Ford CNG systems. “We have some standardized approaches, but the trucks we do are really customized to customer specs, with range and capacity being two of the biggest factors.”

While Knapheide has the capability to design its own CNG systems, it currently takes the technology of others and integrates that into up-fitted vehicles, Weiss says. At present, Knapheide does both conversions and custom designs of CNG trucks at fleet volumes.

The company doesn’t require extra time to integrate CNG into a vehicle. Given this, Weiss says, Knapheide’s lead-time for CNG vehicles is about 14 weeks, about the same for any other standard work truck. Bottom line, though, the long-term cost savings associated with CNG remains one of the main considerations for fleet managers looking to switch to an alternative fuel, Weiss says.

“In the United States, most fleets are driven by pure fuel costs. So fleet managers are constantly looking at the total cost of doing business and there are advantages to using CNG-powered vehicles. However, there are also some fleets driven by the environmental impact benefits of CNG,” says Weiss, adding that low oil and gas prices have reduced orders for CNG vehicles, although he predicts they will eventually rebound as oil prices recover.

Tank maker responds with lighter option

Like Knapheide, Worthington Industries Inc. (www.worthingtonindustries.com) also has a stake in the alternative fuels marketplace, especially given its expertise in manufacturing pressure cylinders used in CNG fuel systems. A Tier 1 OEM automotive supplier headquartered in Columbus, Ohio, Worthington has been producing CNG cylinders since the 1960s and currently has more than 1,000 active tank models. However, growing demand for options with more fuel capacity has led Worthington to introduce a new lightweight, large diameter, 26.2-inch model tank, ideally suited for Class 8 heavy-duty and/or refuse trucks used on longer routes.

“Our use of seamless aluminum liners is what differentiates us in the marketplace,” explains Chris Hanners, an alternative fuels product manager at Worthington. “These new tanks offer superior impact tolerance, superior heat tolerance, and superior fast-filling ability in hot and cold weather … so our tanks allow you to get more fuel on-board thanks to their heat dissipation capabilities, which is important for fleet managers.”

Safety is a top priority for Worthington, which is why its CNG tanks are of aviation grade quality standards, Hanners says.

Worthington currently manufactures around 85 million pressure vessels per year and has hundreds of thousands of CNG tanks in service right now, many used on a variety of service-related vehicles, Hanners adds. Given the growing interest in alternative fuels, Worthington also recently announced the acquisition of dHybrid Systems, a Salt Lake City, Utah-based industry leader in the design and manufacture of CNG fuel systems.

“Low oil prices have had an impact on the alternative fuels movement, but we strongly believe in this market and believe it will continue to grow over the long-term,” Hanners says.

Mark Yontz is a freelance writer from Urbandale, Iowa.