The key for solid waste and recycling fleet operators is knowing the right questions to proactively pose before and during the specification process, particularly when it comes to the CNG fuel tank.
Wayne Powers
Solid waste and recycling firms continue to consider compressed natural gas (CNG) as an alternative to gasoline and diesel for their heavy-duty fleet vehicles for many reasons, including lower fuel costs and reduced emissions. But fleet operators who take an active role in the fuel system specification process of their new CNG-dedicated vehicles can gain maximized driving range, increased safety, improved total cost of ownership and reliable performance over thousands of miles of driving. The key for solid waste and recycling fleet operators is knowing the right questions to proactively pose before and during the specification process, particularly when it comes to the CNG fuel tank.
The Case for Being Proactive
A CNG vehicle uses an engine that has been configured to operate on the pressurized gas. The CNG fuel system is separate from the engine and comprises several components, including hose assemblies, tubing, electrical, hardware, fuel management module, regulators, cabinet and the fuel tank. The chassis manufacturer, the body manufacturer or a third-party upfitter, may integrate the CNG system into a heavy-duty truck.
The fuel tank is arguably the most important of the CNG system components; for example, a refuse collection truck will not move an inch without fuel. But choosing a specific type of fuel tank—particularly its size and construction—is typically not high on the priority list for fleet operators. Nevertheless, fleet operators should proactively communicate the type of fuel tank they require in the CNG fuel system, just as they would specifically request other components, like the transmission, tires and suspension, all of which have implications on the performance, fuel economy and ultimate profitability of the vehicle.
There are different CNG fuel tank types available, each offering a range of sizes, price points and advantages. Since fleet operators have a choice, they should examine their options and advocate for the tanks that make the most sense for their operation.
Questions to Ask About CNG Tanks
So what questions should a fleet operator ask a dealership regarding fuel tanks for their heavy-duty fleet vehicles during the specification process? Consider the following a starter list:
- What type of CNG fuel tanks will be specified? CNG fuel tanks are designed to store the pressurized gas at 3,600 psi, and there are different technologies designed to do that. For example, Type III fuel tanks feature a carbon fiber reinforced aluminum liner that eliminates gas permeation (i.e., gas dissipation through the liner). Factors to consider when choosing between tank technologies include things like the importance of vehicle weight, which is directly influenced by tank weight, and the fleet’s need for fast-filling, or the quick-fueling process that typically takes less than an hour. (Note that this is different than time-filling, which typically takes place over several hours.) The aluminum inner liner of a Type III tank helps dissipate the heat generated during fast-filling, which enables optimal fueling capacity and can translate to increased driving range and fewer fueling stops.
- What impact will extreme weather and driving conditions have on the fuel tanks? Keep in mind that heavy-duty vehicles used in solid waste or recycling applications face severe-duty conditions on an almost daily basis, including everything from extreme heat and cold to low-hanging tree limbs. The choice of CNG fuel tank has implications for those situations. For example, there are no filling restrictions on Type III CNG fuel tanks in hot or cold ambient conditions, and what is more, the, gas-tight aluminum inner liner prevents flexing and fracture of the outer composite shell if there is an impact.
- How will the CNG driving range claims be validated? This question comes down to accountability. If a claim is made about the anticipated driving range of a CNG vehicle, fleet operators should ask for validation in the form of referrals, examples and math. For example, there may be a reference to rated DGE (or diesel gallon equivalency), which is based on the water volume of the CNG fuel tank at 100 percent fill efficiency. But remember, CNG is a gas, so a fleet operator’s counter question should be focused on what the usable DGE is, which provides a more accurate prediction of eventual driving range.
- How will the product be supported? Regardless of the type of tank a dealer or fuel system provider specifies, it is important to know how a fleet operator will be supported in the event that mandatory inspections uncover unusual wear. That not only includes support from the dealer or fuel system provider, but also the fuel tank manufacturer. What is the manufacturer’s longevity and ability to support the long-term use of the tank, including technical expertise and customer service?
Transitioning Your Fleet
These are not the only questions a fleet operator should ask. How fuel tanks can help manage a fleet’s costs should also be paramount, especially how a CNG fuel tank contributes to a fleet’s total cost of ownership (TCO). Further questions about durability should also be addressed, particularly compliance with NFPA 52 regulations, because an important part of the cost equation for fleet operators is liability avoidance.
Factors such as fuel costs, fueling infrastructure and overall maintenance are crucial when considering a CNG fleet for solid waste and recycling firms. But it is also important to review fuel system component details. Fuel tank choice alone will impact long-term vehicle performance, including safety, ROI and reliability. Once a particular tank has been identified, that choice should be communicated to the dealer during the specification process. | WA
Wayne Powers is the Alternative Fuels General Manager for Worthington Industries (Columbus, OH) and leads the strategic growth and day-to-day operations of the company’s Alternative Fuels business. He has led diverse teams of product managers, engineers, marketers and operations experts to develop and market Worthington’s alternative fuels portfolio, which includes compressed natural gas (CNG), propane autogas (LPG) and hydrogen fuel storage technology and platforms, as well as CNG fuel systems. Wayne is responsible for Worthington’s Alternative Fuels business in domestic and international markets, including oversight of the company’s U.S. and European manufacturing operations. He can be reached at [email protected].