PNGV’s Response to the Fifth Report
In its previous five reviews, the National Research Council Standing Committee to Review the Research Program of the PNGV made a number of recommendations, which are documented in published reports (NRC, 1994, 1996, 1997, 1998, 1999). In the fifth report, the committee made specific recommendations related to each of the technologies under development and general recommendations for the program as a whole. Appendix B contains a letter from PNGV to the committee chairman documenting PNGV’s responses to the major recommendations in the Executive Summary of the fifth report (NRC, 1999). PNGV’s responses indicate that the PNGV agrees, for the most part, with the committee’s recommendations and has responded favorably to the committee’s suggestions. Discussions of PNGV’s responses to the technical suggestions and recommendations in the fifth report are incorporated in the corresponding technical sections in chapters 2 and 3.
The following comments relate to two of the major recommendations from the fifth report (the responses below can also be found in Appendix B):
Recommendation. The federal government agencies involved in the PNGV program should review how future emissions requirements (especially NOx and particulates), fuel economy, and carbon dioxide emissions, as well as fuel quality, will affect the choice of the compression-ignition direct-injection engine as the most promising short-term combustion engine technology; a program plan that responds to that assessment should be developed. The PNGV, especially the U.S. Department of Energy and the Environmental Protection Agency, should work closely with the California Air Resources Board on these issues.
PNGV’s Response. In response to pending Tier 2 federal emissions regulations, the PNGV partners have adopted a more aggressive R&D program to reduce NOx and
particulate emissions from the CIDI engine while maintaining its inherently high efficiency and low carbon emissions. Within the Low Emissions Partnership (LEP) lean NOx catalyst and non-thermal plasma cooperative research efforts, a new goal of 90 percent or greater NOx conversion is being considered and selective catalytic reduction (SCR) is being added to the NOx reduction strategies. Fuels and aftertreatment programs continue to be more closely linked to minimize in-cylinder emissions while optimizing the performance of new clean fuels as emission control reductants. Two new three-year cooperative agreements to develop emission control systems for the Ford and DaimlerChrysler PNGV engines have brought the expertise of catalyst suppliers more directly into the program. In addition, the DOE has been working with EPA, Engine Manufacturers Association (EMA) members and emission control manufacturers through the Diesel Emission Control Sulfur Effects (DECSE) project to determine the effects of sulfur in diesel on emission control devices.
The committee is not convinced that PNGV has conducted an adequate analysis of how emission requirements, fuel economy, carbon dioxide emissions, and fuel quality will affect the choice of the CIDI engine. As the committee noted in previous chapters, meeting the Tier 2 emission standards with a CIDI engine will be a formidable challenge, especially in the time frame of the PNGV program. The committee understands that the setting of the Tier 2 standards, although not supported by robust statistical analysis and analytical data, was driven by broad considerations of public health and air quality (Federal Register, 1999). Given the impact of these standards, the committee’s recommendation from the fifth report has become even more important. However, PNGV did not provide a program plan that responds to the recommended assessment.
Recommendation. Without compromising proprietary information of the USCAR partners, the PNGV should conduct in-depth cost analyses and use the results to guide subsystem and vehicle affordability studies.
PNGV’s Response. PNGV agrees that it needs to conduct in-depth cost analyses. This necessarily occurs at the vehicle and subsystem levels. The vehicle-level analyses, completed in 1998, are company and configuration specific and thus can only be reviewed in the individual company proprietary sessions. The PNGV directors used the information from their proprietary analyses to jointly develop subsystem-level cost targets for generic fuel cell and hybrid-electric vehicles.
Each technical team used the targets from these generic models to optimize their respective subsystems. An update of the subsystem cost analyses will be presented by the Technical Teams at the November 1999 Collaborative Peer Review.
The projected production costs of all candidate PNGV vehicles presented to the committee far exceed the cost objectives of the program, which are for a vehicle with equivalent costs of ownership, adjusted for economics, to a 1994 family sedan. The committee received cost estimates for some candidate vehicles from some of the PNGV participants. Because cost is a critical factor, the
committee has requested a detailed review of future cost projections as soon as possible. These projections are extremely important as the program moves toward the development of the production prototype vehicle and as cost reduction becomes an increasing priority.
The committee is also concerned that PNGV has not provided a systematic analysis of the relationship between proprietary cost analyses and the cost targets for vehicle technology subsystems. If the subsystem cost targets are credible, then they should add up to an affordable cost for the vehicle.