Natural Gas Vehicle Technology Forum 2012 Meeting Summary

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TheĀ 2012 Natural Gas Vehicle Technology Forum (NGVTF) meeting focused on research and development needs within the natural gas vehicle industry, for both compressed natural gas (CNG) and liquefied natural gas (LNG), and in both heavy-duty and light-duty applications. Much of the discussions centered on Class 7 and Class 8 trucks. Much of today's CNG and LNG fueling infrastructure development is now taking these vehicle types into account during station design. Representatives from GE and Ryder gave presentations at the meeting and indicated that natural gas as a vehicle fuel is positively impacting in their bottom lines.

Natural Gas Engines

Meeting participants discussed the yet-to-be-released Cummins/Westport ISX 12G natural gas engine, which continues to draw significant interest from fleets across the country. This spark ignited engine can be operated using either CNG or LNG. It is expected to have a considerable impact in the marketplace, because it will likely meet the operating requirements of fleets that use 80,000 GVWR Class 8 trucks. The currently available Cummins/Westport ISLG 8.9L engine lacks sufficient horsepower and torque for loads on the heavier end of the spectrum for this vehicle type; it is very well suited for lighter loads, in both refuse and transit applications, for example. Doosan Infracore spoke about its ongoing development of its GL11K natural gas engine. This engine is primarily targeted to the transit sector, with the ability to expand to other markets at a later date.

Across multiple engine sizes and applications, many of the meeting participants expressed the desire to see engine offerings from a greater selection of manufacturers. Many are optimistic that growth in the market will facilitate such diversification, particularly in heavy-duty applications.

Fuel Prices and Vehicle Production

The price of natural gas as a commodity continues to be the main driving force within the industry. Larger vehicles, which use higher volumes of fuel per vehicle than smaller vehicles do, realize faster returns on investment. Often, fleets with large vehicles also operate smaller support vehicles, and this provides an opening to increase the market share for light-duty vehicles. Chrysler, through its RAM brand, entered the market this year with the only factory produced 5.7 L V-8 pickup truck.

Prior to MY12, Honda had been the only OEM to offer a production-line CNG vehicle. Ford offers CNG vehicles through its Qualified Vehicle Modifier (QVM) program and offers trucks in the F250/350 class with gaseous prep-ready engines. Ford is using the 6.2L engine for this platform. It is also offering the Transit Connect with the 2.0L gaseous prep engine. Ford continues to offer the 5.4L V-8 and 6.8L V-10 as a gaseous prep-ready engine for light- and medium-duty applications. General Motors offers its Chevy Express/GMC Savana and Chevy Silverado/GMC Sierra for CNG operation, both utilizing the 6.0L V-8 engine. These vehicles are produced by GM and then sent to its authorized upfitter. At this point, the natural gas fuel system is installed and then shipped to the selling dealer. This is one step short of being produced on the assembly line.

Vehicles are serviced and supported through authorized dealers. These same models (with the same engine size) are also available with gaseous prep-ready engines for purchasers who may wish to go the EPA/CARB conversion route. Ford, GM, Chrysler, and Honda all offer seamless warranties and ordering processes for their customers.

Vehicle Maintenance and Safety

Meeting presenters discussed considerations and challenges associated with maintenance facilities that service CNG and/or LNG vehicles. This is thought to be one of the primary hurdles for natural gas vehicle deployment. Authorities having jurisdiction (AHJs), in many cases local fire marshals, enforce the safety codes applicable to maintenance facilities. Codes used by the AHJs may vary from one jurisdiction to the next, and this is a source of confusion for fleets and facilities managers, particularly with regard to cost implications.

Another source of confusion and variability from one jurisdiction to the next stems from AHJs interpretations of the codes, which can also influence costs. Meeting presenters indicated that the availability of a guidance document for AHJs would be of great benefit, and could potentially improve the facility upgrade process for many fleets.

Compressed Natural Gas Cylinders

Presenters and participants also discussed CNG cylinder end of life (EOL) at great length. This is a concern not only in the United States, but also elsewhere around the globe. The greatest concern relates to cylinders that are known to have issues and should already have been taken out of service but are still in operation. We know that many of these cylinders are still in the market. Also of concern are cylinders currently in service that have reached their EOL.

Additional concerns arise in regard to the replacement of expired cylinders. In many cases, there are suitable replacement cylinders on the market, but they may not fit properly or have the correct valves or shut-off provisions. It is possible that, by removing the original cylinders, the vehicle becomes less safe. The challenge is that many of these cylinders were built specifically for OEM configurations that are no longer available.

Protocols must be established to identify expired cylinders and remove them from service. Potentially, this could be accomplished through the vehicle registration process administered by local departments of motor vehicles, or perhaps through some type of radio frequency identification (RFID) system. Both of these have significant challenges related to the feasibility and cost of implementation.

Summary by John Gonzales, National Renewable Energy Laboratory